EN 12845 Annex G — Aerosol Product Storage

An aerosol can bursts in a fire and flies up to 5 m while still alight — on site people call it a fire rocket. Annex G classifies aerosol storage into three levels, each with its own design criteria. Getting the classification wrong means opening up the entire rack.

A personal care products distribution warehouse had standard OH3 sprinklers. The stock changed — hairspray and deodorant cans arrived — and the design was never updated. Eight months later a spark from a charging unit ignited one can; within three seconds the neighbouring can burst and a bundle of flame shot 4 m upward. The sprinklers operated, but the OH3 density of 5 mm/min could not absorb that energy. Within twelve minutes 1200 m² of warehouse was destroyed. Annex G is mandatory for aerosol storage; an ordinary hazard classification is simply inadequate.

Aerosol level classification

Level	Contents	Typical products	Fire behaviour
1	Water-based, non-combustible	Water-based mousse, water-based room spray	Cans burst but do not spread fire
2	Moderately flammable (< 50 %)	Some cosmetics, some paints	Burst and ignite the immediate area
3	Highly flammable (≥ 50 %)	Hairspray, deodorant, automotive sprays, insecticides	Rocket effect, flying 3–5 m

The manufacturer's safety data sheet determines the level. Where there is doubt, assume Level 3.

Design densities

Level	Max. storage height	Density	Area	Duration
1	4 m	7.5 mm/min	260 m²	60 min
2, unracked	3.8 m	12.5 mm/min	260 m²	90 min
2, racked with in-rack	7.6 m	12.5 mm/min at ceiling plus in-rack	260 m²	90 min
3, unracked	1.5 m	12.5 mm/min	360 m²	90 min
3, racked with in-rack	4.5 m	12.5 mm/min at ceiling plus in-rack at every level	360 m²	90 min
3, ESFR alternative	10.7 m	K360 ESFR at 3.5 bar	12 sprinklers	60 min

In-rack sprinkler rules

• Level 2: a horizontal line at every level above 3.8 m storage height
• Level 3: a horizontal line at every level above 1.5 m — mandatory
• Spacing: no more than 3 m between heads
• K-factor 80 or 115 (15 mm)
• Minimum operating pressure 2 bar
• Fast-response bulb, RTI ≤ 50
• Water shields, to protect the goods below from dripping

Cut-off barrier design

A Level 3 aerosol block is separated from other commodities and from the external wall by a barrier at least 9 m high, with 60 min fire resistance (REI 60) and a 0.9 m gap left below the sprinklers at the top. Where two Level 3 blocks sit side by side, a 9 m barrier is needed between them as well. Barriers may be suspended from the ceiling or built up from the floor; suspending them is generally more practical.

Field error — mixed stock

A shopping centre logistics warehouse received mixed store deliveries — sometimes textiles, sometimes cosmetics at Level 2 or 3, sometimes documents. The design was OH3. Stock rotation was fast and nobody knew what would arrive on a given day, so aerosol cans ended up placed at random. That practice breaks the Annex G isolation principle outright. The solution was to build one part of the facility to Annex G Level 3, confine aerosols to that area and separate it with a cut-off barrier. Stock management has to be disciplined.

Explosive atmospheres and deflagration

Aerosol cans use LPG (propane or butane) as propellant. A damaged can leaks, and in an enclosed room an explosive atmosphere forms at 1.8–9.5 % by volume. The ATEX Directive (2014/34/EU) may classify a Level 3 store as Zone 22. Precautions:

• At least 4 air changes per hour by mechanical ventilation
• LPG gas detection integrated with the fire alarm panel
• Explosion-protected lighting and electrical installation
• Static earthing of doors and racking
• Roof deflagration venting panels to EN 14491

Worked water demand

Level 3, racked, with in-rack protection over 360 m²: ceiling 12.5 × 360 = 4500 L/min, plus eight in-rack heads at 80 L/min = 640 L/min, plus 500 L/min for hose reels, giving about 5640 L/min. Over 90 min that is 508 m³. That is roughly two-and-a-half to three times the OH3 figure most logistics facilities are built around; Level 3 aerosol protection demands serious capacity.

Passive measures

• Storage height limit marked and visibly signed
• Fire load in kg/m² tracked
• Damaged cans moved immediately to a separate disposal area
• Hot work prohibited inside the store
• Forklift battery charging in a separate room
• Absolute ban on smoking and any source of flame
• Trained staff, with a drill every three months

Comparison with NFPA 30B

NFPA 30B, covering the manufacture and storage of aerosol products, is the detailed counterpart to Annex G. The three levels are the same, but NFPA gives more weight to ESFR solutions — a Level 3 store is typically twelve K360 ESFR heads at 3.5 bar. NFPA 30B accepts a 25 ft (7.6 m) barrier height where EN 12845 requires a stricter 9 m. International retail chains operating in Turkey generally apply NFPA 30B with the FM Global interpretation.

Turkish regulation and local practice

BYKHY gives no separate class for aerosol stores, treating them under high-hazard storage. In practice insurers ask for Annex G or NFPA 30B. Large international cosmetics manufacturers build their Turkish logistics warehouses to Annex G Level 3 with ESFR and cut-off barriers. Domestic brand warehouses frequently run into the inadequacy of OH3, and a risk assessment usually triggers a design upgrade.

Quick check list

• Level (1, 2 or 3) established from the safety data sheets.
• Design density matches the level.
• Storage height within the limit and visibly marked.
• In-rack sprinklers at every level (Level 2 above 3.8 m, Level 3 above 1.5 m).
• Cut-off barrier for Level 3, 9 m high with REI 60.
• ATEX assessment and gas detection in place.
• Deflagration venting panels where an enclosed room holds large quantities.
• Tank sized for 90 min duration.
• Stock management prevents mixed storage.

Frequently Asked Questions

How are aerosols classified under Annex G?

Into three levels by flammable content: Level 1 water-based, Level 2 under 50 % flammable, Level 3 at or above 50 % flammable. Where the safety data sheet is unclear, assume Level 3.

What storage height is allowed for Level 3 aerosols?

Only 1.5 m unracked. With in-rack sprinklers at every level it rises to 4.5 m, and with a K360 ESFR ceiling design up to 10.7 m.

What is the cut-off barrier requirement?

A 9 m high barrier with REI 60 fire resistance, separating a Level 3 block from other commodities and from external walls, with a 0.9 m gap left below the sprinklers.

Does an aerosol store need an ATEX assessment?

Often yes. LPG propellant leaking from damaged cans can form an explosive atmosphere, and a Level 3 store may be classified as Zone 22, requiring mechanical ventilation, gas detection and explosion-protected electrical installation.

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