Soap, Detergent, Surfactant, Household-Cleaning & Personal-Care Manufacturing HVAC Duct Guide

1. Why soap, detergent and cleaning-products HVAC is its own engineering discipline

Soap, detergent, surfactant and household-cleaning manufacturing is one of the most chemically diverse process industries operating in Australia, and it concentrates more distinct airborne hazards under one roof than almost any other consumer-goods sector. Inside a single plant — the Unilever Australia laundry-powder works at Tatura in regional Victoria, the Colgate-Palmolive site at Villawood in western Sydney, the Reckitt facility at West Ryde, PZ Cussons at Villawood, Pental’s soap and household works at Shepparton, or Symex’s oleochemical and soap-noodle plant at Coolaroo — you can find a 250 °C spray-drying tower throwing off fine combustible detergent powder in one bay, a falling-film sulphonation reactor liberating sulphur trioxide and acid mist in another, a fully enclosed enzyme-dosing booth containing one of the lowest-exposure respiratory sensitisers in the entire occupational-hygiene standard a few metres away, a fragrance-dosing station off-gassing perfume VOC, a saponification line steaming caustic mist, and an aerosol gassing line pressurising air-freshener cans with flammable LPG propellant in a hazardous-area room. Each of these processes carries its own characteristic dust load, fume chemistry, ignition risk, corrosion profile, hazardous-area zoning requirement and material specification.

HVAC ductwork inside a cleaning-products plant is therefore not a commodity item. It is a process-engineering problem that touches AS 3957 combustible-dust deflagration safety, AS/NZS 60079.10.2 dust and AS/NZS 60079.10.1 gas hazardous-area electrical compliance, AS 1940 flammable-liquid and aerosol-propellant control, AS 3780 corrosive-substances segregation, AS/NZS 1715 and AS/NZS 1716 respiratory-protection selection for sensitisers, AS/NZS 2243.8 laboratory fume-cupboard design, and the full suite of SafeWork Australia workplace exposure standards (WES) — from the 2 ppm limit on sulphur dioxide and the 1 ppm limit on chlorine down to the roughly 60 nanogram-per-cubic-metre guideline on subtilisin enzyme dust, all sitting inside the same building envelope and frequently sharing make-up air. A generic commercial fabricator who treats a detergent plant as just another industrial extract job loses money on the first project and walks away from the second, because the duct material, the seam construction, the bonding, the deflagration protection and the corrosion allowance are different in almost every bay.

This guide writes against the full breadth of the Australian cleaning-products sector as it exists in 2026. Spray-dried laundry detergent is the highest-hazard tier — Unilever Australia produces OMO, Surf, Sunlight and the Dove personal-wash range with manufacturing and contract-manufacturing links across Tatura VIC and Minto NSW; Colgate-Palmolive Australia at Villawood NSW produces Palmolive, Dynamo and Cold Power; Reckitt Australia at West Ryde NSW produces Dettol, Finish and Vanish. Soap and oleochemical manufacture is anchored by Pental at Shepparton VIC (Velvet soap, White King, Pears, Jiffy firelighters) and Symex at Coolaroo VIC (soap noodles, fatty acids and oleochemical feedstocks that supply the wider soap industry), with Deluxe Soap and a number of contract soap makers filling out the segment. Liquid and aerosol household-cleaning products come from PZ Cussons at Villawood (Morning Fresh dishwashing liquid, Radiant laundry), SC Johnson Australia (air fresheners, surface sprays, insecticides), Procter & Gamble Australia, and Henkel. Institutional and industrial cleaning chemistry is dominated by Ecolab and Diversey, with Campbell Brothers/Chemlink and a long tail of regional blenders supplying contract and private-label product. The Australian Made Campaign and ACCORD Australasia (the peak body for the hygiene, cosmetic and specialty-products industry) span the whole sector. Geographically the industry clusters around Tatura, Shepparton and Coolaroo in Victoria; Villawood, West Ryde, Minto and Wetherill Park in New South Wales; with further capacity in Brisbane QLD and Perth WA.

Across this entire sector, cleaning-products ductwork must survive five simultaneous demands. Combustible-dust deflagration resistance (AS 3957 dust-hazard zoning, AS/NZS 60079.10.2 Zone 20/21/22, conductive flange gaskets and continuous earth bonding, NFPA 68 vent panels and NFPA 69 isolation on baghouses for spray-dried detergent powder, surfactant powder and sodium percarbonate). Aggressive chemical-fume and corrosion resistance (sulphur dioxide and sulphur trioxide acid mist from sulphonation, sulphuric acid mist, chlorine from sodium hypochlorite bleach, caustic NaOH mist from saponification, ammonia from ammoniated cleaners). High-temperature service (200–300 °C spray-dryer hot-gas inlet and tower exhaust, soap-dryer heat, gas-fired air-heater combustion products). Respiratory-sensitiser containment (enzyme protease, amylase, lipase and cellulase dust at nanogram exposure targets; perfume and fragrance sensitisers). And flammable-atmosphere hazardous-area control (LPG propellant in aerosol filling, ethanol and solvent flash-off, all under AS/NZS 60079.10.1 and AS 1940). Each is manageable in isolation. Together they explain why cleaning-products HVAC is a specialist fabrication discipline rather than a commodity supply.

This guide walks every major process zone and explains what changes about the ductwork. We start with the Australian regulatory backbone, then map the plant section by section — spray-drying tower, sulphonation, enzyme containment, perfume dosing, soap making, powder blending and packing, liquid filling and bleach, aerosol filling, combustible-dust deflagration, and the QC laboratory — then close with the dilution-ventilation calculation method, the SBKJ machine configuration that gives an Australian fabricator the production envelope to serve this market from Box Hill North VIC, commissioning and measurement-and-verification, the standards table, and the energy and sustainability trends reshaping the sector.

2. The Australian regulatory stack — AS 1668, AS 4254, AS 3957, AS/NZS 60079, AS 1940, AS 3780, AS/NZS 2243.8, AS 1375 and the WES

Cleaning-products HVAC in Australia sits at the intersection of more than two dozen overlapping standards and codes. Ignoring any one of them is a notice of non-compliance from SafeWork Australia, the state EPA, or both, waiting to happen. The stack splits into building-code and mechanical-ventilation compliance, occupational-health exposure compliance, combustible-dust safety, hazardous-area electrical compliance, flammable-liquid and corrosive-substances control, laboratory ventilation, fired-equipment safety, and the quality and environmental management systems that wrap the whole operation.

2.1 AS 1668.1 and AS 1668.2 — fire mode and mechanical ventilation

AS 1668.1 covers the fire-mode and smoke-management requirements of air-handling systems, including fire and smoke dampers, fan shutdown and the interaction of the mechanical system with the building fire-safety design. AS 1668.2 is the umbrella mechanical-ventilation and contaminant-control standard. Cleaning-products plants fall under NCC Class 8 industrial occupancy; AS 1668.2 sets minimum outdoor-air and dilution rates and, critically, the methodology for sizing dilution ventilation against contaminant generation rate and the relevant workplace exposure standard. In practice a detergent or soap plant seldom runs near the building-volume minimum — localised exhaust ventilation (LEV) at each dust and fume source drives total exhaust well above the dilution figure. Where AS 1668.2 matters most is make-up air: every cubic metre extracted from a spray-dryer, a powder blender, an enzyme booth, a sulphonation vent or an aerosol gassing room must be replaced by tempered, filtered, controlled-velocity supply air, keeping production zones at the correct pressure relationship to office, laboratory and packing zones and preventing back-migration of dust, acid mist, chlorine or propellant into occupied spaces.

2.2 AS 4254.1 and AS 4254.2 — sheet-metal and flexible duct construction

AS/NZS 4254.1 (sheet metal) and AS/NZS 4254.2 (flexible) govern duct construction across the normal pressure ranges — low pressure (up to 500 Pa), medium pressure (up to 1000 Pa) and high pressure (up to 2500 Pa). Most cleaning-products supply air, general extract and LEV branches sit inside AS 4254 ranges. The hot spray-dryer tower-to-cyclone section, in its insulated heavy-gauge form, sits at the upper end or beyond and requires purpose-engineered construction with expansion provision; AS 4254 picks up again on the cooler side downstream of the cyclone. AS 4254 sets the gauge, reinforcement, joint and sealing requirements that the fabricated duct must meet, and the pressure-test regime (typically 1.5x design pressure held for 30 minutes) that proves it at commissioning.

2.3 AS 3957 — dust hazard areas, the central detergent-plant standard

AS 3957 is the Australian dust-hazard standard and the single most directly applicable document for the detergent and surfactant powder duct designer. It covers combustible-dust deflagration risk and forces the question at every dust-collection point: what is the explosibility of this dust, what is its minimum ignition energy, what is its deflagration index Kst, and what is the engineered deflagration-protection chain between the baghouse and the inbound duct? Spray-dried detergent powder, post-dosed surfactant powder, sodium percarbonate oxygen-bleach, sodium carbonate and many builder and filler blends are combustible organic-bearing dusts. AS 3957 mandates hazard-area zoning — Zone 20 for continuous explosible-dust concentration (the interior of a baghouse, a closed hopper, a blender, a dust main above settling velocity), Zone 21 for occasional release (around an open sieve, a transfer point, a bag-dump station), Zone 22 for unlikely release (the general powder-handling room) — and drives the AS/NZS 60079.10.2 electrical-equipment selection downstream. The answer drives baghouse selection, isolation-valve placement, vent-panel sizing and the bonding-and-grounding of every metre of duct in the dust-laden circuit.

2.4 AS/NZS 60079.10.2 (dust) and AS/NZS 60079.10.1 (gas) — explosive atmospheres

AS/NZS 60079 is the hazardous-area-classification standard, and a cleaning-products plant triggers both parts. AS/NZS 60079.10.2 (combustible dust) classifies the detergent and surfactant powder circuits into Zone 20/21/22 as above. AS/NZS 60079.10.1 (flammable gas and vapour) classifies the aerosol gassing line and propellant store (LPG — propane/butane — and dimethyl ether), the ethanol and solvent areas, and any flammable-VOC handling into Zone 0/1/2:

• Zone 20: Continuous explosible-dust concentration — interior of detergent baghouse, powder hopper, blender, sieve enclosure, dust main above settling velocity.
• Zone 21: Occasional explosible-dust release in normal operation — bag-dump station, open transfer point, immediate area around a sieve discharge.
• Zone 22: Unlikely dust release, short duration — general powder-handling and packing room around the equipment.
• Zone 1 (gas): Flammable gas/vapour likely in normal operation — the immediate envelope around an aerosol gasser head and crimp/seam station, the propellant transfer point.
• Zone 2 (gas): Flammable gas/vapour unlikely in normal operation — the general aerosol gassing room, ethanol-handling areas.

AS/NZS 60079 drives Ex-rated electrical equipment for fans, motors, instrumentation, duct-mounted sensors and lighting inside or near the affected zones, selected to the correct gas group (IIA for propane/butane) and dust group. Ductwork in dust zones must be conductive throughout (316L stainless is the default), continuously bonded with conductive flange gaskets, externally strapped to the building earth grid, and verified at commissioning to less than 1 ohm to ground at every section. Ductwork in the aerosol gas zones must likewise be conductive and bonded to prevent a static spark igniting an LPG leak.

2.5 AS 1940 — storage and handling of flammable and combustible liquids and aerosols

AS 1940 governs the storage and handling of flammable liquids and aerosol products in Australian workplaces, and it is central to the aerosol-filling and solvent areas of a cleaning-products plant. The LPG propellant (a propane/butane blend) is a flammable liquefied gas; the bulk propellant store, the transfer lines and the gasser are all designed under AS 1940 in combination with AS/NZS 60079.10.1 hazardous-area zoning. Ethanol used in glass cleaners and some sprays is a Class IB flammable liquid; fragrance concentrates and solvent carriers may be combustible liquids. Finished aerosol cans are themselves an AS 1940 aerosol-storage class with quantity limits and segregation rules. Each storage and handling point requires bunded containment where liquid, a dedicated LEV branch, segregated storage and AS/NZS 60079 zoning around the immediate work area.

2.6 AS 3780 — the storage and handling of corrosive substances

AS 3780 governs corrosive substances — and a cleaning-products plant is full of them. Concentrated sulphuric acid and oleum for sulphonation, the SO₃ and acid-mist streams themselves, sodium hydroxide (caustic soda) for saponification and liquid-product pH adjustment, sodium hypochlorite bleach and the chlorine it liberates, hydrochloric acid in some descaling and acidic-cleaner products, and ammonia. AS 3780 sets the segregation rules that are the single most important safety principle in the liquid plant: acids and hypochlorite must be stored, bunded and ducted separately so that no single spill, cross-connection or ventilation failure can bring an acid and a hypochlorite stream together and liberate chlorine gas. The corrosive-duty LEV duct material (FRP, high-grade stainless or coated steel) is selected against the specific corrosive in each branch, and the branches are kept physically and aerodynamically separate.

2.7 AS 1530.4 — fire-resistance of building elements and duct penetrations

AS 1530.4 covers fire-resistance testing of building elements, including fire-rated ductwork penetrations through fire compartments. In a cleaning-products plant this matters at every wall and floor penetration between a hazardous production zone (spray-dryer hall, powder-handling Zone 20/21/22, aerosol gassing room, flammable-liquid store) and adjacent office, laboratory, warehouse or evacuation zones. The penetration must be fire-rated — commonly 250 °C/2 hour integrity for the duct itself — with fire dampers complying with AS 1682 and the surrounding wall/floor assembly meeting the fire-resistance level (FRL) called by the building’s National Construction Code approval. The aerosol store, with its large quantity of flammable propellant, drives some of the highest FRLs in the building.

2.8 AS/NZS 2243.8 — laboratory fume cupboards

AS/NZS 2243.8 is the Australian standard for laboratory fume cupboards and is the governing document for the QC and R&D laboratory ventilation in every cleaning-products plant. The lab handles acids, solvents, fragrance concentrates, surfactant samples and analytical reagents; fume cupboards must achieve and maintain a face velocity in the 0.5 m/s band (typically 0.5 m/s average with no point below a specified minimum), with the exhaust ducted in corrosion-resistant material (316L stainless or FRP depending on the chemistry handled) to a dedicated lab-exhaust fan and stack discharging clear of intakes. AS/NZS 2243.8 also governs containment performance testing, monitoring and alarms.

2.9 AS 1375 — industrial fuel-fired appliances (dryers and furnaces)

AS 1375 (the SAA Industrial Fuel-Fired Appliances Code) covers the safe operation of the gas-fired or oil-fired air heaters that supply hot drying gas to the spray-drying tower, the soap dryer and any heated process. It sets purge, ignition, flame-supervision and safety-interlock requirements on the burner and combustion system, and it interacts directly with the HVAC design: the combustion-air supply, the products-of-combustion path through the dryer and into the exhaust train, and the carbon-monoxide and oxygen monitoring on the heated circuit all derive from AS 1375 and the associated gas-installation requirements. NFPA 86 (industrial ovens and furnaces) is frequently used as a cross-reference engineering basis where additional detail is needed on purge cycles and burner-management systems.

2.10 AS 4024, AS/NZS 1715/1716, AS/NZS 3000 and the management-system standards

AS 4024 (safety of machinery) governs guarding, access and interlocks on the duct, fan and collector plant, including the inspection-access ports and personnel-entry provisions. AS/NZS 1715 (selection, use and maintenance of respiratory protective equipment) and AS/NZS 1716 (respiratory protective equipment) govern the powered air-purifying respirators (PAPR) and full-face respirators mandated for enzyme-dosing operators and for any breach of containment around sensitisers, acids or chlorine — the HVAC system reduces the airborne hazard but RPE is the last line of defence and its selection is documented against each task. AS/NZS 3000 (the Wiring Rules) governs the general electrical installation, working with AS/NZS 60079 on the hazardous-area portions. Wrapping all of it, ISO 9001 (quality), ISO 14001 (environmental, tied to the stack-emissions licence) and ISO 45001 (occupational health and safety, tied to the WES air-monitoring regime) are the management-system standards that most Australian cleaning-products manufacturers certify to, and ASHRAE 62.1 is frequently used as a supplementary ventilation-rate reference alongside AS 1668.2. NCC Section J sets the building energy-efficiency requirements that increasingly drive heat-recovery on the spray-dryer exhaust.

3. The spray-drying tower — hot, abrasive, combustible detergent-powder exhaust

The spray-drying tower is the defining process of a powder-detergent plant and the most demanding single HVAC duty in the sector. A hot aqueous slurry — the “crutcher” mix of sodium sulphate, sodium carbonate, sodium silicate, anionic surfactant paste, builder and minor ingredients — is pumped at high pressure and atomised through nozzles into the top of a tall tower. Hot drying gas, generated by a gas-fired air heater and entering at 200–300 °C, rises (counter-current) or falls (co-current) through the falling droplet curtain, flashing off the water and leaving hollow detergent granules that collect at the base. The drying gas leaves the tower hot, humid, and laden with fine detergent powder (fines below 10–20 micron), surfactant fume and the products of combustion from the air heater. That exhaust stream is the problem the duct designer must solve.

The exhaust train is, in sequence, a cyclone (or bank of cyclones) for bulk-fines recovery, a bag filter (baghouse) for the fine particulate that the cyclone misses, frequently a wet scrubber for residual fume, odour and any acidic gas, and finally an induced-draught fan and stack. The duct between the tower outlet and the cyclone is the hardest section. It runs hot, so it must be heavy-gauge insulated aluminised steel or 316L stainless with engineered thermal-expansion provision (bellows joints). It carries hard inorganic fines at velocity, so it abrades — the transport velocity must stay high enough to keep fines entrained (18–22 m/s in the dust-laden mains) but the duct wall and especially the elbows must be specified with an abrasion allowance, generous bend radii and sometimes wear-back elbows. And the fines are a combustible organic-bearing dust, so the entire circuit is designed under AS 3957 and AS/NZS 60079.10.2 with deflagration protection on the baghouse.

Round spiral duct is the correct geometry for the spray-dryer exhaust mains downstream of the cyclone. A round cross-section is uniformly streamlined — there are no flat panels for hard fines to settle on and build a smouldering nest, and the aerodynamic profile holds transport velocity through elbows and branches without the dropout pockets that become deflagration ignition points. The hot heavy-gauge tower-to-cyclone section is fabricated as purpose-engineered transitions and straight runs; the cooler dust mains from the cyclone to the baghouse are spiral. Carbon-monoxide monitoring (WES 30 ppm) on the dryer flags incipient smouldering in the powder bed or the duct, and the air-heater combustion is supervised under AS 1375. Energy recovery from this 150–250 °C exhaust (after particulate removal) is increasingly mandated under NCC Section J and is discussed in the energy section below.

4. Surfactant sulphonation — SO₂, SO₃ and sulphuric-acid-mist acid-resistant ductwork

The workhorse anionic surfactant in laundry and dishwashing products is linear alkylbenzene sulphonate (LAS), and it is made by sulphonating linear alkylbenzene (LAB) with sulphur trioxide (SO₃) in a falling-film reactor. SO₃ is an extremely aggressive reagent; it is generated on site by burning molten sulphur to sulphur dioxide (SO₂) and then catalytically converting the SO₂ to SO₃ in a converter. The process gas streams around the sulphur burner, the converter, the falling-film reactor, the digestion/ageing vessels and the neutralisation stage carry sulphur dioxide, sulphur trioxide and sulphuric-acid mist — all acutely hazardous and savagely corrosive. The SafeWork Australia workplace exposure standard for SO₂ is 2 ppm (8-hour TWA), and for SO₃ and sulphuric-acid mist it is 0.2 mg/m³ — both low, and both demanding tight capture and scrubbing.

The ductwork serving the sulphonation plant cannot be plain carbon or galvanised steel; sulphuric-acid mist destroys ordinary steel rapidly. The correct envelope is acid-resistant throughout — 316L stainless at minimum for the drier process-vent and work-area capture branches, frequently upgraded to higher-molybdenum stainless or to FRP (fibreglass-reinforced plastic) on the wet scrubber inlet and outlet where the stream is saturated with acid mist. The vent gas is drawn to a packed-bed or venturi caustic scrubber sized to pull SO₂ and acid mist reliably below the WES before the cleaned gas reaches the induced-draught fan and stack. AS 3780 governs the storage and handling of the molten sulphur, the oleum and the product acid streams, and demands segregation from any incompatible chemistry elsewhere in the plant. The acid duct is fully welded (no mechanical lock-seam leak path), conductive and bonded, and pressure-tested at commissioning. Continuous SO₂ monitoring at the stack and in the work area, interlocked to trip the process and step up scrubber duty on a high reading, is standard practice.

5. Enzyme handling — the respiratory-sensitiser containment that defines the plant’s hardest LEV

Enzymes are the single most hazardous airborne agent handled in a modern detergent plant, and the LEV that contains them is the most safety-critical ventilation system in the building. Proteolytic and other enzymes — protease (subtilisin), amylase, lipase, mannanase and cellulase — are dosed into laundry powders, laundry liquids, dishwasher products and pre-treaters to digest protein, starch, fat and other stain components. Subtilisin is a potent respiratory sensitiser: once a worker becomes sensitised, vanishingly small future exposures can trigger occupational asthma and allergic rhinitis, and the sensitisation is generally permanent and career-ending for work around enzymes. The accepted airborne action level is extraordinarily low — industry and occupational-hygiene guidance places it around 60 nanograms per cubic metre as a short-term (15-minute) value, roughly one-thousandth of a typical particulate workplace exposure standard and far below the threshold of any general dust-collection system.

This single fact drives the entire enzyme-handling ventilation design. The enzyme containment LEV is completely separate from the general detergent-dust system — it never shares duct, fan or filter with anything else, so that an enzyme breach cannot contaminate, and cannot be diluted-away inside, the bulk powder circuit. Every enzyme dosing, weighing, transfer and addition point is totally enclosed, with high capture-velocity hooded extraction (typically 1.0–1.5 m/s face velocity at the enclosure opening) pulling air inward so no enzyme dust escapes the enclosure. The extracted air passes through HEPA filtration before any recirculation or discharge, because the particle is so hazardous that ordinary bag filtration is insufficient. The dosing operation is conducted in negative-pressure containment booths, and any operator who must break containment wears powered air-purifying respiratory protection (PAPR) selected to AS/NZS 1715 and AS/NZS 1716. Enzymes are supplied to the plant as low-dust encapsulated prills or granules specifically to suppress airborne release, but the ductwork is still designed as if a sensitiser breach is possible: hermetically welded 316L stainless, smooth-bore with no internal ledges where granules could accumulate and later be re-entrained, gentle bends, and a dedicated HEPA-protected fan. The breathing-zone air monitoring around the enzyme area is the most frequent and most carefully managed sampling in the plant’s ISO 45001 occupational-hygiene programme.

6. Perfume and fragrance dosing — VOC and sensitiser fume capture

Almost every cleaning product carries a fragrance, and the perfume-dosing station — where neat fragrance oils and the carrier solvents are metered into the product base — is a concentrated source of volatile organic compounds (VOC) and, frequently, dermal and respiratory sensitisers (limonene, linalool, citral and a long list of regulated fragrance allergens). The fragrance compounds themselves are odorous at extremely low concentrations, so even small uncaptured releases create a strong perfume haze across the plant and a genuine sensitisation and nuisance exposure for operators. The control is a dedicated local exhaust ventilation hood over the dosing, weighing and mixing point, capturing the VOC and sensitiser fume at source before it disperses, ducted in 316L stainless to a fan and, where the VOC load or odour warrants it, to a carbon-adsorption or scrubbing stage before discharge.

The perfume LEV runs on its own branch, separate from the dust and acid systems, because the fragrance oils are organic liquids that would foul a dust baghouse and because the odour load needs its own treatment. The carrier solvents (frequently ethanol, WES 1000 ppm, or a glycol) bring a minor flammability consideration that ties the dosing area into AS 1940 and, depending on quantity and volatility, a Zone 2 classification under AS/NZS 60079.10.1. The duct is conductive and bonded as a precaution against static in the solvent-vapour stream. Because the fragrance allergens are sensitisers, source capture (not dilution) is the mandated primary control, with the same engineering logic as the enzyme system though at a less extreme exposure target.

7. Soap making — saponification caustic mist, glycerine, heat and soap dust

Soap manufacture — Pental at Shepparton VIC (Velvet, Pears), Symex at Coolaroo VIC (soap noodles and oleochemical feedstock), Deluxe Soap and the contract soap makers — runs a different hazard profile from synthetic-detergent manufacture, dominated by caustic mist, heat and soap dust rather than combustible-powder explosion. The core reaction is saponification: fats and oils (tallow, palm, coconut and other triglycerides) are reacted with sodium hydroxide (caustic soda, NaOH) to produce soap and glycerine. Continuous saponification and the subsequent neutralising, washing and drying stages run hot and handle strong caustic. The airborne hazard at the saponification and caustic-handling stages is sodium-hydroxide mist — the SafeWork Australia WES for NaOH is 2 mg/m³ (peak limit), and caustic mist is corrosive to the respiratory tract and to ordinary duct steel. The caustic-handling and saponification vents are captured to 316L stainless LEV and scrubbed.

Downstream, the neat soap is dried (vacuum spray-drying or atmospheric drying) into soap pellets or noodles, then milled, plodded, extruded, cut and stamped into bars or sold as noodles to other manufacturers. The drying and finishing stages generate heat (and water vapour and glycerine carry-over from the dryer) and soap dust at the noodle, flake, milling, stamping and packing stations. Soap dust is captured by LEV hoods over each dust-generating point, ducted at 18–22 m/s transport velocity to a cyclone and baghouse. Soap dust is combustible (it is an organic fatty material), so although it is generally less aggressively explosible than spray-dried synthetic-detergent powder, the dust circuit is still assessed under AS 3957 and the baghouse is fitted with appropriate deflagration protection where the dust-hazard analysis calls for it. The soap dryer’s heat source is supervised under AS 1375, and the warm glycerine-laden dryer exhaust is a candidate for heat recovery.

8. Powder blending, post-dosing and packing — detergent dust and enzyme-dust LEV

After the spray-dryer produces base powder, modern detergent manufacture rarely stops there. The base granule is conveyed to blending and post-dosing, where heat-sensitive and reactive ingredients that cannot survive the dryer — enzymes, perfume, sodium percarbonate or perborate oxygen-bleach, bleach activators (TAED), anti-foam, optical brighteners, colour speckles and dry surfactant — are dosed onto or blended with the base powder. The blended product is then conveyed to packing, where it is filled into cartons, bags, pouches or tubs. Every transfer, blend, dose and fill point is a dust-generation source, and the dust is the combustible spray-dried detergent powder plus whatever has been post-dosed into it — including, critically, enzyme dust.

The blending and packing LEV is a network of capture hoods over each dust point — blender charge and discharge, conveyor transfer, bag-dump stations, sieve discharges, packing-machine fill heads — ducted at 18–22 m/s transport velocity into a cyclone and baghouse, all assessed under AS 3957 and zoned Zone 20/21/22 under AS/NZS 60079.10.2. The general detergent-dust WES (treated as a nuisance/particulate limit around the sodium-carbonate figure of 10 mg/m³ inhalable, with the deflagration hazard the governing design driver rather than the toxicity) sets the capture target for the bulk powder. But the enzyme post-dosing point is the exception that dominates the design: it is enclosed and served by the completely separate enzyme containment LEV described in section 5, never sharing duct with the bulk powder system, because the enzyme sensitiser exposure target is three orders of magnitude lower than the bulk-dust target. The packing area, where operators spend full shifts, carries the most intensive breathing-zone monitoring outside the enzyme room. Smooth round spiral duct is again the correct geometry to avoid dropout pockets and smouldering nests in the combustible-dust mains.

9. Liquid filling — minor VOC, sodium-hypochlorite bleach chlorine off-gas and ammonia

The liquid side of a cleaning-products plant fills dishwashing liquid, fabric softener, liquid laundry detergent, surface sprays, bleach and a range of speciality cleaners. Most liquid filling is a comparatively low-hazard operation — minor VOC flash-off from fragrance and solvent across the open filler, captured by light LEV over the filling heads. Two streams are the exception and demand serious corrosion-resistant ventilation: bleach and ammoniated products.

Liquid bleach is sodium hypochlorite solution. During filling and bulk storage it slowly off-gasses chlorine, and if it is ever brought into contact with an acid — a spill, a wrong-line cross-connection, or an acidic product such as a toilet cleaner sharing a line — it liberates chlorine gas rapidly and dangerously. Chlorine is acutely toxic: the SafeWork Australia WES is 1 ppm. It is also corrosive to most metals, and chloride attacks ordinary 304 and 316 stainless over time through pitting and stress-corrosion cracking. The bleach filler, the hypochlorite bulk storage and the dosing area therefore need a dedicated corrosion-resistant LEV: capture hoods over the filler heads and storage vents, ducted in FRP or chlorine-rated coated duct (FRP is common on the wet, chlorine-laden sections precisely because chloride pits stainless), to a packed-bed caustic scrubber that holds the stack discharge below the WES. AS 3780 governs the corrosive-substances storage and, above all, the segregation: hypochlorite must be stored, bunded and ducted entirely separately from any acid stream so that a single ventilation or containment failure can never bring the two together. Chlorine monitoring with alarm at the filler and storage area is standard, and the room ventilation is arranged for rapid purge in an upset.

Ammoniated cleaners (some glass and multi-surface products) off-gas ammonia, WES 25 ppm, which is corrosive and pungent and — like hypochlorite — must never share duct with a chlorine stream (ammonia and chlorine react). Ammonia capture follows the same corrosion-resistant LEV principle on its own dedicated branch. The general fabric-softener and dishwash filling lines, with only minor VOC, sit on lighter LEV in 316L stainless, with the make-up air balanced under AS 1668.2 so the filling hall stays at the correct pressure relationship to the warehouse and office.

10. Aerosol filling — LPG propellant flammable hazardous-area design

Aerosol products — air fresheners, spray-and-wipe surface cleaners, oven cleaners, insect sprays, fabric refreshers — are the most explosion-hazardous operation in the cleaning-products sector, and the hazard is the propellant. The propellant is almost always LPG (a propane/butane blend) and sometimes dimethyl ether (DME); all are flammable gases. The single governing fact is the lower explosive limit (LEL): butane and propane form a flammable atmosphere with air at concentrations from roughly 1.8–2.1% by volume upward, and because LPG is denser than air, any leak during gassing sinks and pools at floor level. The aerosol gassing room is therefore a hazardous area under AS/NZS 60079.10.1 — typically Zone 1 in the immediate envelope around the gasser head and crimp/seam station where a release is likely in normal operation, and Zone 2 across the surrounding room where a release is unlikely — with the bulk propellant store designed under AS 1940.

Every electrical device inside the classified zones — extract fans, motors, lighting, instrumentation, duct-mounted sensors — must be Ex-rated to the zone and to gas group IIA (propane/butane), in accordance with AS/NZS 60079 and AS/NZS 3000. The ventilation is engineered on AS 1668.2 dilution principles to ensure that the worst-credible leak is diluted well below the LEL at any normally-occupied position — the conventional design target is to keep concentration below 25% LEL everywhere a person could be. Because LPG sinks, the extract is taken at low level (floor-level extract grilles and trenches) rather than at the ceiling, ducted in conductive, continuously-bonded, spark-free 316L stainless to an Ex-rated extract fan discharging to a safe high-level external location away from intakes and ignition sources. A high air-change rate is provided continuously while the line runs, with LEL gas detection interlocked to escalate ventilation, stop gassing and alarm on a rising reading. Propellant simple-asphyxiation in confined low spots (a pit, a sump, a trench) is a secondary hazard managed by the same low-level extract plus oxygen and LEL monitoring and AS 2865 confined-space controls. The conductive, bonded duct is not optional here: a static spark from an ungrounded duct in an LPG-vapour stream is a credible ignition source, and the bonding-to-earth verification (below 1 ohm at every section) is a safety-critical commissioning item.

11. Combustible-dust deflagration — AS 3957, AS/NZS 60079.10.2 and the NFPA 68/69 protection chain

The combustible-dust deflagration hazard runs through the whole powder side of the plant — the spray-dryer exhaust, the cyclone and baghouse, the blending and post-dosing circuit, the packing dust system, the surfactant-powder handling and the sodium-percarbonate oxygen-bleach handling. Spray-dried detergent powder, surfactant powder and percarbonate are combustible organic-bearing dusts (percarbonate additionally is an oxidiser, raising the stakes). When such a dust is suspended in air above its minimum explosible concentration inside a confined volume — a baghouse, a duct, a blender, a hopper — an ignition source can cause a deflagration; and a primary deflagration that bursts a vessel can loft settled dust off ledges and floors to feed a far more destructive secondary explosion through the building. This is the scenario the entire dust-system design exists to prevent.

Australian detergent plants treat their powder circuits under AS 3957 (dust hazard areas) and AS/NZS 60079.10.2 (combustible-dust hazardous-area classification), and use the international engineering references NFPA 68 (deflagration venting) and NFPA 69 (explosion prevention by inerting, oxidant concentration reduction, or suppression) for the protection design. The process starts with a written dust hazard analysis (DHA) that establishes, for each dust, its deflagration index Kst, its minimum explosible concentration, its minimum ignition energy and its ignition-sensitivity, and that maps every point of dust generation, accumulation, potential ignition and potential propagation through the plant. The protection of the ductwork and collectors then combines several engineered layers: explosion-relief vent panels sized to NFPA 68 on baghouses and large vessels, directed to a safe location; explosion-isolation valves (chemical-suppression barriers, fast-acting flap valves or rotary valves, selected against the dust Kst and the duct size) installed between each collector and its inbound duct so a deflagration in the baghouse cannot propagate back along the main and into the building; rigorous elimination of ignition sources (Ex-rated electrical equipment to the zone, full earth-bonding of every conductive duct section to below 1 ohm to ground, conductive flexible connections, bonded and grounded rotary valves and screw conveyors, and good housekeeping to prevent settled-dust nests); and smooth round spiral duct geometry that holds transport velocity and avoids the dropout pockets where dust settles, smoulders and ignites. The isolation-valve interlock pre-trips on flame or pressure rise sensed inside the collector. Carbon-monoxide monitoring (WES 30 ppm) on the dryer and any thermal source provides early warning of incipient smouldering before it becomes an ignition event.

12. QC and R&D laboratory fume cupboards — AS/NZS 2243.8

Every cleaning-products plant runs a quality-control and product-development laboratory, and its ventilation is governed by AS/NZS 2243.8. The lab handles concentrated acids and caustics for titration and analysis, organic solvents for extraction and chromatography, neat fragrance concentrates, surfactant actives, hypochlorite and a range of analytical reagents — a chemistry mix as varied as the plant itself, but at small scale and high concentration. The fume cupboards must achieve and hold a controlled face velocity in the 0.5 m/s band (commonly an average of 0.5 m/s with no point falling below a specified minimum, verified by the AS/NZS 2243.8 containment and performance tests), with continuous face-velocity monitoring and audible/visual alarms on low flow.

The fume-cupboard exhaust is ducted in corrosion-resistant material selected against the chemistry handled — 316L stainless for general solvent and mixed duty, FRP or a fluoropolymer-lined duct where concentrated acids or hypochlorite are routinely handled — to a dedicated laboratory-exhaust fan and stack that discharges clear of all building air intakes and at sufficient velocity and height to disperse safely. The lab exhaust is kept entirely separate from the process LEV systems. Make-up air to the laboratory is tempered and balanced so the room stays at slight negative pressure relative to adjoining offices, and the fume-cupboard extract is the dominant exhaust path. For the highest-hazard analytical work, ducted fume cupboards (not recirculating filtered cabinets) are mandatory, and the duct, fan and discharge are designed and commissioned as a single system under AS/NZS 2243.8.

13. Workplace exposure standards and the dilution-ventilation calculation

Source capture by local exhaust ventilation is always the primary control in a cleaning-products plant, because it removes a contaminant at high concentration in a small airflow at the point of release. Dilution ventilation — flooding a space with clean air to keep the average concentration below the workplace exposure standard — is the fallback for diffuse, low-toxicity releases that cannot be captured at source, such as ethanol or fragrance-solvent flash-off across an open liquid-filling line, or trace ammonia from a glass-cleaner blend. AS 1668.2 sets the method.

The required dilution airflow follows directly from the contaminant generation rate and the target airborne concentration. The governing relationship is Q = (G × K) / C_target, where Q is the volumetric dilution airflow, G is the mass generation rate of the contaminant, C_target is the design airborne concentration, and K is a mixing-efficiency safety factor (commonly 3 to 10) applied because real rooms never mix perfectly and because peaks exceed the average. The design target concentration is set well below the WES — typically one-tenth — to protect for imperfect mixing, transient peaks and overlapping exposures. Worked example: for a process releasing ethanol vapour at a measured rate, with the ethanol WES at 1000 ppm and a design target of one-tenth (100 ppm) and a mixing factor applied, the dilution airflow is the generation rate divided by the design concentration, multiplied by the mixing factor — a calculation that typically returns a large airflow, which is exactly why dilution is expensive to run (it tempers and moves a great deal of air) and why source capture is always preferred where it is feasible.

The same relationship sizes dilution for the other diffuse contaminants in the plant against their WES values: ammonia (25 ppm), carbon dioxide build-up in occupied spaces (5000 ppm), and perfume VOC (treated against the relevant component limits). It is essential to understand where dilution is not acceptable as a primary control. For respiratory sensitisers (enzyme, at roughly 60 ng/m³) and for acutely toxic gases (SO₂ at 2 ppm, chlorine at 1 ppm, SO₃/sulphuric-acid mist at 0.2 mg/m³), dilution can never be relied upon — containment and source capture are mandatory, because the consequence of a single elevated exposure (permanent sensitisation, acute chemical injury) is too severe to manage by averaging. The following WES values anchor the plant’s design and its breathing-zone monitoring programme: sulphur dioxide 2 ppm; sulphur trioxide / sulphuric-acid mist 0.2 mg/m³; subtilisin enzyme respiratory sensitiser approximately 60 ng/m³ (note the nanogram scale — three orders of magnitude below ordinary dust limits); chlorine 1 ppm; ammonia 25 ppm; sodium hydroxide / caustic mist 2 mg/m³; ethanol 1000 ppm; LPG / butane / propane treated as a simple asphyxiant with the LEL as the governing design limit; detergent and sodium-carbonate dust 10 mg/m³ inhalable (with deflagration the governing driver); carbon monoxide 30 ppm; carbon dioxide 5000 ppm.

14. The SBKJ machine line for cleaning-products duct fabrication

Fabricating cleaning-products-grade ductwork in an Australian shop requires the right machine fit, the right process discipline and the right documentation. The duct must be hot-and-abrasion-capable for the spray-dryer exhaust, acid-and-chlorine-resistant for the sulphonation and bleach branches, hermetic for the acid, caustic, enzyme and perfume branches, conductive and bonded for every dust and aerosol-gas zone, and traceable for the ISO 9001 / ISO 45001 quality and safety audit. The SBKJ Product Catalog 2026 covers the full envelope from Box Hill North VIC:

SBAL-V — auto duct line with stainless option, handling galvanised and 304/316L stainless from 0.7 mm to 1.6 mm. Used for the bulk of supply and general extract ductwork, the 316L hermetic envelope for acid, caustic, enzyme and perfume LEV, and the rectangular sections that feed the stitch welder. TDF flange formed in line.

SBAL-III — heavy-gauge auto duct line for 1.6–2.0 mm work. Used for the insulated hot spray-dryer tower-to-cyclone mains, large baghouse-inlet mains, and the heavy general-exhaust mains downstream of the cyclone and dryer cooling section.

SBSF-1525 — longitudinal stitch welder laying a continuous TIG bead on the lock-seam joint. Travel speed 600–900 mm/min on 1.2 mm 316L with argon shield gas at 12 L/min. The critical machine for hermetic acid-mist (sulphonation), chlorine (bleach), caustic-mist (saponification), enzyme-containment and perfume LEV duct — the continuous bead leaves no mechanical lock-seam leak path.

SB-ZF1500 — longitudinal stitch welder for trunk-main continuous TIG seam, running in-line with the SBFB-1500 spiral former. Used for combustible detergent-dust mains and acid-mist mains above 1000 mm diameter, giving the double-bond (mechanical spiral lock plus continuous TIG weld) construction that the deflagration and corrosion duties demand.

SBFB-1500 — spiral tubeformer producing spiral round duct 80–1500 mm diameter in 0.6–1.5 mm galvanised, aluminised or stainless. The single most-used machine for cleaning-products duct: spray-dryer exhaust mains, detergent-dust collection mains, soap-dust mains, blending and packing dust mains and acid-mist scrubber mains. Round spiral geometry holds transport velocity and avoids dropout pockets in combustible-dust service.

SBPC1500 — plasma cutter handling stainless and Inconel up to 25 mm thickness with HD plasma quality. Used for spray-dryer tower-hood transitions, cyclone transitions, acid-mist and bleach scrubber inlet/outlet cones, custom hot-face transitions and the stainless transition pieces that integrate metal mains with bought-in FRP on the wettest acid and chlorine sections.

SBLR-600 — lock former producing Pittsburgh lock and snap-lock longitudinal seams for rectangular duct, with the heavy-gauge tooling set for 1.2 mm 316L hermetic and corrosion-resistant service.

SBTF-1500/1602/2020 — spiral former family for trunk mains 1500–2000 mm diameter, used for centralised dust circuits serving multiple dryers or blenders, large baghouse-inlet trunk mains and supply trunk mains at the highest-volume installations.

The combined machine fit delivers the production envelope to cover every duct requirement across every Australian cleaning-products operator — from the Unilever powder works at Tatura and the Colgate-Palmolive site at Villawood, to Reckitt at West Ryde, PZ Cussons at Villawood, Pental at Shepparton, Symex at Coolaroo, SC Johnson, Procter & Gamble Australia, Henkel, Ecolab and Diversey.

15. How the major Australian operators differ from an HVAC perspective

The Australian cleaning-products sector is not one HVAC problem but four overlapping ones, and each named operator sits at a different point in the mix.

15.1 Unilever Australia — OMO, Surf, Sunlight, Dove (Tatura VIC, Minto NSW)

Unilever Australia spans spray-dried laundry powder (OMO, Surf), liquids, and the Dove personal-wash range, with manufacturing and contract-manufacturing links across Tatura in regional Victoria and Minto in south-western Sydney. The dominant HVAC loads are the spray-drying tower exhaust (hot, abrasive, combustible-dust), the enzyme containment LEV (the sensitiser hazard in laundry powder), perfume dosing LEV, and the blending-and-packing dust system, all under AS 3957 and AS/NZS 60079.10.2 with NFPA 68/69 protection on the baghouses. A hot, dusty, deflagration-controlled plant requiring the full spray-dryer and combustible-dust envelope.

15.2 Colgate-Palmolive Australia — Palmolive, Dynamo, Cold Power (Villawood NSW)

Colgate-Palmolive Australia at Villawood NSW produces the Palmolive, Dynamo and Cold Power ranges across powder, liquid and personal-care formats. The HVAC stack mirrors Unilever’s on the powder side — spray-dryer exhaust, combustible detergent-dust collection, enzyme containment and perfume LEV — with additional liquid-filling LEV. Villawood is one of the long-established western-Sydney detergent sites and a benchmark for combustible-dust and enzyme-containment practice.

15.3 Reckitt Australia — Dettol, Finish, Vanish (West Ryde NSW)

Reckitt Australia at West Ryde NSW produces Dettol, Finish (automatic-dishwashing products, heavily enzyme- and bleach-active) and Vanish (oxygen-bleach stain removers, sodium-percarbonate-based). The HVAC emphasis here is strongly on enzyme containment, sodium-percarbonate oxidiser-dust handling (combustible and oxidising, demanding careful dust-hazard analysis), and perfume LEV. Percarbonate handling sharpens the deflagration and reactivity case under AS 3957.

15.4 PZ Cussons — Morning Fresh, Radiant (Villawood NSW)

PZ Cussons at Villawood NSW produces Morning Fresh dishwashing liquid and the Radiant laundry range. The HVAC profile leans liquid — dishwash and liquid-laundry filling LEV (minor VOC), perfume dosing LEV, with corrosion-resistant branches for any bleach or pH-adjustment chemistry — a lighter overall stack than a spray-dryer plant but with the same hermetic-stainless and corrosion-resistant fabrication discipline on the active branches.

15.5 Pental — Velvet, White King, Pears, Jiffy (Shepparton VIC)

Pental at Shepparton VIC is the classic Australian soap-and-household manufacturer — Velvet and Pears bar soap (saponification, caustic mist, soap drying and dust), White King bleach (sodium hypochlorite, chlorine off-gas, corrosion-resistant LEV), and Jiffy firelighters. The HVAC stack combines saponification caustic-mist LEV, soap-dust collection, and the corrosion-resistant chlorine LEV of the bleach line — a caustic-mist, moderate-dust and chlorine-corrosion plant rather than a high-temperature spray-dryer plant.

15.6 Symex — soap noodles and oleochemicals (Coolaroo VIC)

Symex at Coolaroo VIC is the upstream oleochemical and soap-noodle producer that supplies fatty acids, glycerine and soap base to the wider industry. The HVAC stack is dominated by saponification and fatty-acid processing caustic mist and heat, soap-noodle drying and dust, and the high-temperature, heat-recovery-rich exhaust of the oleochemical splitting and distillation columns. A caustic, hot, dust-and-fume plant feeding the rest of the sector.

15.7 SC Johnson, P&G, Henkel and the aerosol/liquid majors

SC Johnson Australia (air fresheners, surface sprays, insecticides) brings the aerosol-filling LPG-propellant hazardous-area HVAC to the fore — AS/NZS 60079.10.1 Zone 1/2, AS 1940 propellant storage, floor-level Ex-rated extract. Procter & Gamble Australia and Henkel span powder, liquid and personal-care formats with the corresponding mix of dust, perfume and corrosion-resistant LEV. The aerosol operators are where the LEL-driven hazardous-area design dominates over dust and corrosion.

15.8 Ecolab, Diversey and the institutional blenders

Ecolab and Diversey produce institutional and industrial cleaning and sanitising chemistry — concentrated liquids, some powder dosing, strong acids, caustics and chlorine-release products for food-industry, healthcare and commercial cleaning. Their blending plants combine concentrated-liquid handling LEV, minor powder-dosing dust collection, and a broad corrosive-chemical LEV demand under AS 3780, with the segregation of acid, chlorine and ammonia streams the central safety principle. Campbell Brothers/Chemlink and the regional contract blenders sit in the same category at varying scale.

16. Commissioning, monitoring and AS/NZS measurement-and-verification

Commissioning cleaning-products ductwork is more demanding than commissioning generic industrial HVAC, because the consequence of getting it wrong spans deflagration, acute chemical injury and permanent sensitisation. The compliance documentation required at handover includes pressure-test records (1.5x design pressure for 30 minutes per AS 4254) on every branch; earth-bonding verification at every flange (resistance below 1 ohm to ground) on every dust and aerosol-gas duct; conductivity verification on every conductive flexible connection; NATA-certified airflow balance against the design schedule for every LEV hood, fume cupboard and dilution system; the AS 3957 dust-hazard analysis tied to the AS/NZS 60079.10.2 zone map; the AS/NZS 60079.10.1 gas zone map for the aerosol and solvent areas; scrubber-performance verification proving SO₂ (2 ppm), sulphuric-acid mist (0.2 mg/m³) and chlorine (1 ppm) discharge below the WES; LEL-detection commissioning on the aerosol line; and the enzyme containment-and-monitoring verification proving the sensitiser exposure target is met.

Ongoing monitoring runs daily, weekly, monthly and annual cycles. Daily: continuous gas monitoring at the operator interface (SO₂ at sulphonation, chlorine at the bleach line, LEL at the aerosol gasser, CO at the dryer), pressure differential across each baghouse (alarm at ±25% of design), and stack particulate monitoring per the state EPA licence. Weekly: visual inspection of duct interiors at access ports for powder accumulation (the smouldering-nest check), condition of bonding straps and conductive flange gaskets, and condition of scrubber packing. Monthly: airflow-balance verification at key LEV branches and fume cupboards, explosion-isolation-valve and fire-damper actuation tests, fan-vibration measurement. Quarterly: NATA-certified breathing-zone air sampling against the WES for every operator-occupied zone — with the enzyme area sampled most intensively — fed into the ISO 45001 occupational-hygiene system. Annual: full system pressure test, full bonding-resistance re-verification, scrubber re-packing and caustic make-up, baghouse vent-panel and isolation-valve inspection, and Ex-equipment inspection per AS/NZS 60079.17. Every length of duct SBKJ supplies is delivered with mill certificate, fabrication date, pressure-test record, earth-bonding verification at every flange and AS/NZS-compliant labelling — the foundation paperwork the operator integrates into its ISO 9001, ISO 14001 and ISO 45001 audit pack.

17. Standards and workplace-exposure-standard reference table

The following table consolidates the standards, codes and exposure limits referenced throughout this guide, mapped to the cleaning-products process zone each one governs.

Standard / limit	Scope	Cleaning-products application
AS 1668.1	Fire mode of air-handling systems	Fire/smoke dampers, fan shutdown across the whole plant
AS 1668.2	Mechanical ventilation & dilution	Make-up air, dilution-ventilation calculation against WES
AS/NZS 4254.1 / .2	Sheet-metal & flexible duct construction	Gauge, reinforcement, sealing, pressure test on all duct
AS 3957	Dust hazard areas	Detergent/surfactant/percarbonate combustible-dust zoning
AS/NZS 60079.10.2	Explosive atmospheres — dust	Zone 20/21/22 powder circuits, baghouse, blender, dust mains
AS/NZS 60079.10.1	Explosive atmospheres — gas	Zone 1/2 aerosol LPG gassing, ethanol/solvent areas
AS 1940	Flammable & combustible liquids/aerosols	LPG propellant store, ethanol, aerosol-can storage
AS 3780	Corrosive substances	Sulphuric acid, oleum, caustic, hypochlorite segregation
AS 1530.4	Fire resistance of building elements	250 °C/2 h fire-rated duct penetrations at compartments
AS/NZS 2243.8	Laboratory fume cupboards	QC/R&D fume cupboards, 0.5 m/s face velocity
AS 1375	Industrial fuel-fired appliances	Spray-dryer & soap-dryer air-heater burner safety
AS 4024	Safety of machinery	Guarding, access ports, interlocks on duct/fan/collector
AS/NZS 1715 / 1716	Respiratory protective equipment	PAPR for enzyme dosing, acid, chlorine breach
AS/NZS 3000	Wiring rules	General electrical install; works with AS/NZS 60079
NCC Section J	Building energy efficiency	Spray-dryer exhaust heat-recovery drivers
ASHRAE 62.1	Ventilation for acceptable IAQ	Supplementary ventilation-rate reference
ISO 9001 / 14001 / 45001	Quality / environmental / OHS	Management systems, emissions licence, WES monitoring
NFPA 68 / 69	Deflagration venting / explosion prevention	Vent panels & isolation on combustible-dust baghouses
WES — SO2	2 ppm (8-h TWA)	Sulphonation process & work-area capture
WES — SO3 / H2SO4 mist	0.2 mg/m³	Sulphonation acid-mist scrubber
WES — subtilisin enzyme	~60 ng/m³ (respiratory sensitiser)	Enzyme containment LEV — nanogram scale
WES — chlorine	1 ppm	Sodium-hypochlorite bleach filling/storage
WES — ammonia	25 ppm	Ammoniated-cleaner filling
WES — NaOH / caustic mist	2 mg/m³	Saponification, soap caustic handling
WES — ethanol	1000 ppm	Glass-cleaner & solvent flash-off dilution
LEL — LPG/butane/propane	Simple asphyxiant + LEL ~1.8–2.1% vol	Aerosol propellant — design below 25% LEL
WES — detergent/Na2CO3 dust	10 mg/m³ inhalable	Powder handling (deflagration governs design)
WES — CO	30 ppm	Dryer smouldering early-warning monitoring
WES — CO2	5000 ppm	Occupied-space build-up dilution

18. Spray-dryer heat recovery and process-ventilation energy

The spray-drying tower is the single largest energy consumer in a powder-detergent plant, and its exhaust is the single largest recoverable heat stream. The air heater burns gas to raise the drying-gas inlet to 200–300 °C; the tower exhaust still leaves at 150–250 °C after the product has dried. Discharging that heat to atmosphere is both an operating-cost and a carbon penalty, and NCC Section J increasingly requires that it be addressed in new and refurbished plant. The standard recovery route is a heat exchanger downstream of the particulate-removal stage (after the cyclone and baghouse, so the recovery surface does not foul or abrade) transferring heat from the cleaned exhaust into the incoming combustion or process air, or into plant hot-water and space-heating loads. The recovery duct and exchanger must still be corrosion-aware — the exhaust can carry residual surfactant fume and acidic combustion products, and cooling it risks dropping below the acid dew point and condensing corrosive liquid, so the exchanger material and the minimum metal temperature are engineered to stay above the dew point.

Beyond the dryer, process-ventilation energy is dominated by the large volumes moved through the dust, scrubber and dilution systems. Every cubic metre of make-up air that replaces extracted air must be filtered and frequently tempered, so the most effective energy strategy is the same as the most effective hygiene strategy: maximise source capture (small airflow at high concentration) and minimise dilution (large airflow at low concentration). Variable-speed drives on the LEV and dilution fans, interlocked to run only when the served process is operating, cut fan energy substantially across a plant that historically ran fixed-speed fans continuously. Heat recovery on the general extract (via run-around coils or thermal wheels, kept off the corrosive and dust streams) recovers tempering energy from the bulk air changes. The duct itself contributes through low-leakage construction — a hermetically welded 316L main loses far less conditioned or extracted air than a poorly sealed lock-seam duct, which is both an energy and a containment benefit.

19. Sustainability, concentrated formulas and the refill trend

The cleaning-products sector is in the middle of a sustainability-driven reformulation that is reshaping its manufacturing — and therefore its HVAC. The dominant trend is concentration: laundry liquids, dishwashing liquids and surface cleaners are being concentrated to reduce water, packaging and freight, with refill pouches and refill stations reducing single-use packaging. Concentration shifts the manufacturing balance away from high-volume water removal (less spray-drying energy per unit of active delivered) and toward precise handling of more-concentrated actives, surfactants and fragrances — which raises the per-handling-event exposure and tightens the LEV requirement at dosing and filling even as total throughput volume falls. Compaction of powders (smaller-dose “ultra” powders and tablets) similarly concentrates the dust hazard into smaller, more potent quantities.

Enzyme and bio-based actives are growing as replacements for harsher chemistry and phosphate builders, which increases the prominence of the enzyme containment LEV that already defines the plant’s hardest ventilation. Fragrance reformulation toward allergen-reduced and naturally-derived profiles keeps the perfume LEV in focus. On the propellant side, the long-running shift in aerosols toward compressed-gas and bag-on-valve systems and away from LPG reduces (but does not eliminate) the flammable-propellant hazardous-area burden, while DME and LPG remain widespread. Each of these reformulations feeds back to ductwork: more hermetic stainless for concentrated actives and enzymes, sustained corrosion-resistant capacity for the acid, caustic and chlorine chemistries that are not going away, and the heat-recovery and variable-speed energy measures that the sustainability and NCC Section J agenda now expect as standard in new fabrication.

20. Green Star, NABERS, DDA accessibility and the building envelope

New and refurbished cleaning-products manufacturing and warehouse buildings are increasingly delivered to Green Star (the Green Building Council of Australia’s rating tool) and benchmarked under NABERS (the National Australian Built Environment Rating System) for energy and water performance. For the HVAC fabricator this translates into demands for low-leakage duct construction (hermetically welded mains lose less conditioned air and score better on the energy model), heat recovery on the spray-dryer and general exhaust, variable-speed fan operation, and documented commissioning and measurement-and-verification that feed the rating evidence. The ISO 14001 environmental-management system and the state EPA stack-emissions licence sit alongside these ratings.

Accessibility is governed by the Disability Discrimination Act and AS 1428.1 (design for access and mobility), which apply to the office, amenities, control-room and accessible-route portions of the building. While AS 1428.1 does not dictate process-duct routing, it constrains the placement of plant, risers and access ways through occupied and public-facing areas, and it interacts with the mechanical design where ducts, plant rooms and service risers pass through or adjoin accessible routes and amenities. A competent fabricator coordinates duct routing and plant-room access with the accessibility design so that maintenance access to fans, dampers and access ports does not compromise an accessible path of travel.

21. Industry bodies, competitive positioning and the SBKJ offer

The Australian cleaning-products sector is represented by ACCORD Australasia, the peak national industry association for the hygiene, cosmetic and specialty-products industry, which covers formulators, manufacturers and ingredient suppliers and engages on regulation, sustainability and product stewardship. The Accord-linked programmes and the Australian Self-Medication Industry (ASMI, for the adjacent self-care and personal-health products that some of these manufacturers also produce) shape the regulatory environment in which the plants operate. The Australian Made Campaign certifies and promotes locally manufactured product, a positioning that matters to several of the named soap and cleaning brands. Standards Australia publishes the AS/NZS standards that govern the HVAC; SafeWork Australia sets the workplace exposure standards; the state EPAs licence the stack emissions; and the Green Building Council of Australia and NABERS administer the building-performance ratings.

From a competitive-positioning standpoint, the cleaning-products HVAC market rewards fabricators who understand the chemistry, not just the sheet metal. A generic commercial duct shop can quote a galvanised supply-air job, but it cannot correctly specify a hermetically welded 316L acid-mist main for a sulphonation plant, an FRP-integrated chlorine LEV for a bleach line, a deflagration-protected combustible-dust circuit for a spray-dryer, or the totally-enclosed HEPA-protected enzyme containment that the sensitiser hazard demands — and it cannot produce the bonding, pressure-test and material-traceability documentation that the ISO 9001/14001/45001 audit and the AS 3957 dust-hazard analysis require. SBKJ Group’s position is to give Australian fabricators the machine envelope (SBAL-V, SBAL-III, SBSF-1525, SB-ZF1500, SBFB-1500, SBPC1500, SBLR-600, SBTF-1500/1602/2020) to fabricate every one of those duties locally, to specification, with the documentation built in — from Box Hill North VIC to detergent, soap, surfactant and household-cleaning plants across the country.

22. Compliance checklist for cleaning-products duct fabrication and commissioning

A short-form compliance checklist for cleaning-products ductwork commissioning, suitable for inclusion in handover documentation:

• AS 1668.2 mechanical ventilation — design extract, dilution and make-up air calculations documented for every zone against the relevant WES.
• AS 4254 duct construction — pressure-test certificates at 1.5x design pressure for 30 minutes on every branch.
• AS 1530.4 fire resistance — fire-rated penetrations certified at 250 °C/2 hour at every fire-compartment boundary, with AS 1682 fire dampers.
• AS 3957 dust hazard areas — written dust hazard analysis covering Kst, minimum ignition energy, minimum explosible concentration and the deflagration-protection chain.
• AS/NZS 60079.10.2 (dust) — documented Zone 20/21/22 map for every powder circuit with electrical-equipment selection per AS/NZS 60079.0–.31.
• AS/NZS 60079.10.1 (gas) — documented Zone 1/2 map for the aerosol LPG gassing line and solvent areas, gas group IIA equipment.
• AS 1940 flammable & combustible liquids/aerosols — LPG propellant, ethanol and aerosol-can storage documented and segregated.
• AS 3780 corrosive substances — sulphuric acid, caustic, hypochlorite and ammonia storage and LEV branches documented and segregated so acid and chlorine streams never combine.
• AS/NZS 2243.8 fume cupboards — documented face velocity, containment test and dedicated exhaust path for QC/R&D laboratory.
• AS 1375 fuel-fired appliances — burner purge, flame supervision and interlocks documented on the spray-dryer and soap-dryer air heaters.
• AS/NZS 1715 / 1716 respiratory protection — PAPR and respirator selection documented for enzyme dosing and any acid/chlorine breach task.
• AS 2865 confined-space entry — permit system for baghouse, scrubber, tower and propellant-pit entry.
• NFPA 68 deflagration venting and NFPA 69 explosion prevention — vent panels and isolation valves documented for every combustible-dust collector.
• Scrubber performance — verified SO₂ below 2 ppm, sulphuric-acid mist below 0.2 mg/m³, chlorine below 1 ppm at discharge.
• Enzyme containment — verified sensitiser exposure target met, dedicated HEPA-protected system, separate from bulk dust.
• Bonding verification — resistance below 1 ohm to ground at every flange and isolation valve on dust and aerosol-gas duct; conductive flexible-connection conductivity tested.
• ISO 9001 / 14001 / 45001 — material traceability, emissions-licence evidence and quarterly breathing-zone WES sampling documented.
• NABERS / Green Star — low-leakage construction, heat recovery and variable-speed evidence where the building is rated.
• NATA certification — final commissioning balance and breathing-zone sampling certified by a NATA-accredited laboratory.

Compliance documentation is the bridge between the fabricated ductwork and the operator’s ongoing regulatory obligation. Every length of ductwork SBKJ supplies to an Australian cleaning-products fabricator is delivered with mill certificate, fabrication date, pressure-test record, earth-bonding verification at every flange and AS/NZS-compliant labelling — the foundation paperwork the operator integrates into its dust-hazard analysis, hazardous-area dossier and ISO management-system audit pack.

23. Closing — SBKJ engineering support for Australian cleaning-products manufacturing

The Australian soap, detergent, surfactant and household-cleaning sector is reformulating and re-equipping simultaneously — concentrating product, growing enzyme and bio-based chemistry, tightening energy and emissions performance, and replacing ageing first-generation HVAC infrastructure across the established Victorian (Tatura, Shepparton, Coolaroo) and New South Wales (Villawood, West Ryde, Minto, Wetherill Park) manufacturing clusters and the Queensland and Western Australian capacity beyond them. Every one of those transitions exposes the limits of generic commercial HVAC and demands purpose-engineered ductwork that meets the full standards stack in this guide — combustible-dust deflagration protection for the spray-dryer and powder circuits, acid-resistant construction for sulphonation, corrosion-resistant construction for bleach and caustic, totally-enclosed containment for enzyme, and Ex-rated hazardous-area construction for aerosol propellant. The SBKJ Group engineering team in Box Hill North VIC is positioned to support Australian fabricators serving this sector with machine supply (SBAL-V, SBAL-III, SBSF-1525, SB-ZF1500, SBFB-1500, SBPC1500, SBLR-600, SBTF-1500/1602/2020), engineering documentation, commissioning support and ongoing technical advisory across every process zone described in this document.

We will be exhibiting at ARBS 2026 in Sydney in May with the full SBKJ machine portfolio plus cleaning-products-specific reference samples covering hermetically welded 316L acid-mist and enzyme-containment envelope, combustible-detergent-dust spiral with deflagration-protection detailing, hot spray-dryer exhaust transitions, and FRP-integrated chlorine LEV. Pre-show meetings with Australian cleaning-products fabricators, machine OEM partners and existing customers are scheduled across the week.