Source: TS EN 12845+A2:2026, Clause G.8 "Polypropylene or polyethylene storage bins", G.8.1-G.8.4 (EN p.151), the continuation of G.8.4 and G.8.5 (EN p.152).
PP/PE storage bins (plastic bins) are the only product in Annex G for which a foam additive is required. The clause consists of five sub-clauses, and every one of them is either numerical or binding.
G.8.1 General
Clause G.8.1 (EN p.151): "The following requirements shall be met unless other types of sprinkler protection are shown to be valid by appropriate fire testing."
That sentence defines the only legitimate route away from the clause: fire testing.
G.8.2 Classification
Clause G.8.2 (EN p.151) is a single sentence: "Polypropylene and polyethylene storage containers shall be classified as HHS Category IV."
Clause G.8 gives no separate density/area table for this product. The design density and the area of operation are taken from Table 4 for Category IV (ceiling protection only, EN p.38), or from Table 5 (EN p.39) where in-rack sprinklers are present.
Table 4, Category IV: relevant rows
Maximum storage heights for Category IV and the corresponding design criteria in the ST1 (free-standing or block stacking) and ST4 (palletized racks) row groups:
| Category IV maximum height (m), ST1 | Category IV maximum height (m), ST4 | Design density (mm/min) | Area of operation (m2) |
|---|---|---|---|
| 1.6 | 1.6 | 7.5 | 260 |
| 2.0 | 2.0 | 10.0 | 260 |
| 2.3 | 2.3 | 12.5 | 260 |
| 2.7 | 2.7 | 15.0 | 260 |
| 3.0 | 3.0 | 17.5 | 260 |
| 3.3 | 3.3 | 20.0 | 300 |
| 3.6 | 3.6 | 22.5 | 300 |
| 3.8 | 3.8 | 25.0 | 300 |
| 4.1 | 4.1 | 27.5 | 300 |
| 4.4 | 4.4 | 30.0 | 300 |
Source: Table 4, EN p.38.
Since Clause G.8.4 limits storage outside racks to 3 m, the Category IV 3.0 m row of Table 4 applies in that case: 17.5 mm/min, 260 m2.
G.8.3 Palletized rack storage (ST4)
Clause G.8.3 (EN p.151):
| Item | Value |
|---|---|
| Horizontal spacing of in-rack sprinklers | does not exceed 1.5 m |
| Vertical distance between in-rack sprinklers | does not exceed 2 m |
| Ceiling sprinkler sensitivity rating | 'Special' |
| In-rack sprinkler sensitivity rating | 'Special' or 'Quick' |
The hydraulic assumptions for in-rack sprinklers come from the general provision (Clause 7.2.3.3, EN p.37): the 3 most unfavourable sprinklers on each level, over a maximum of three levels; one rack where the aisle is 2.4 m wide or more, two racks where it is between 1.2 m and 2.4 m, and three racks where it is narrower than 1.2 m.
G.8.4 All other storage
Clause G.8.4 (EN p.151-152):
- The maximum storage height does not exceed 3 m.
- Only non-inflammable pallets, for example steel pallets, are used.
- The stack height per pallet does not exceed 1 m.
- The uppermost storage container on each pallet is closed with a lid.
- The sprinklers have a sensitivity rating of 'Special' or 'Quick'.
G.8.5 Foam additive
Clause G.8.5 (EN p.152): "A suitable film forming foam, used in accordance with the supplier's recommendation, shall be added to the sprinkler water."
NOTE (EN p.152): "In full scale fire tests, AFFF (aqueous film forming foam) has been shown to be effective."
This is the only place in Annex G where a foam additive is stipulated. The standard gives no foam concentration here (1%, 3%, 6%), no concentrate volume, no type of proportioning system and no foam product standard; it uses only the expressions "a suitable film forming foam" and "in accordance with the supplier's recommendation".
Summary table
| Item | Provision | Source |
|---|---|---|
| Classification | HHS Category IV | G.8.2, EN p.151 |
| Route for departure | Appropriate fire testing | G.8.1, EN p.151 |
| In-rack horizontal spacing | <= 1.5 m | G.8.3, EN p.151 |
| In-rack vertical distance | <= 2 m | G.8.3, EN p.151 |
| Ceiling sensitivity (ST4) | 'Special' | G.8.3, EN p.151 |
| Maximum height outside racks | 3 m | G.8.4, EN p.151 |
| Stack per pallet | <= 1 m | G.8.4, EN p.151 |
| Pallet material | Non-inflammable, for example steel | G.8.4, EN p.151 |
| Uppermost container | With a lid | G.8.4, EN p.152 |
| Foam | Film forming foam mandatory | G.8.5, EN p.152 |
What the standard does not say here
- ESFR design, K-factor, operating pressure or number of sprinklers. There is no ESFR in Clause G.8; for ESFR, Annex P (normative, EN p.164) refers to EN 12845-2.
- Any other stack height limit outside racks such as 1.2 m. The only limit is 3 m (1 m per pallet).
- A specific separation distance for outdoor storage. The general provision is in Clause 5.2 (EN p.30): at least 10 m or 1.5 times the height of the material, where not regulated by legislation.
- Mixed stacking rules or a separate class for plastic bins inside cardboard boxes.
- Numerical limits on ceiling slope, roof light area or smoke vent openings. For ESFR/CMSA these subjects are dealt with in EN 12845-2 Clause 5.2.
Field note
Field note (not from the standard, this is engineering interpretation): in this clause the foam additive is not an option but part of the design, so at project acceptance the foam proportioning arrangement and the concentrate stock have to be documented as components of the system. The requirement for non-inflammable pallets is also the item most easily breached on the operator's side.
Frequently Asked Questions
Which category do PP/PE storage bins fall into?
TS EN 12845+A2:2026 Clause G.8.2 (EN p.151): polypropylene and polyethylene storage containers are classified as HHS Category IV. The design density and the area of operation are taken from Table 4 (EN p.38) on the basis of that category.
What are the in-rack sprinkler spacings for palletized rack storage?
Clause G.8.3 (EN p.151): the horizontal spacing of in-rack sprinklers does not exceed 1.5 m and the vertical distance between in-rack sprinklers does not exceed 2 m. Ceiling sprinklers have a sensitivity rating of 'Special', while in-rack sprinklers have a sensitivity of 'Special' or 'Quick'.
Which limits apply to storage outside racks?
Clause G.8.4 (EN p.151-152): the maximum storage height does not exceed 3 m. Only non-inflammable pallets, for example steel pallets, are used. The stack height per pallet does not exceed 1 m and the uppermost storage container on each pallet is closed with a lid. The sprinklers have a sensitivity rating of 'Special' or 'Quick'.
Is a foam additive mandatory?
Yes. Clause G.8.5 (EN p.152): a suitable film forming foam, used in accordance with the supplier's recommendation, is added to the sprinkler water. NOTE: in full scale fire tests, AFFF (aqueous film forming foam) has been shown to be effective.
Can these requirements be departed from?
Clause G.8.1 (EN p.151): the requirements of G.8 shall be met unless other types of sprinkler protection are shown to be valid by appropriate fire testing.
References
- TS EN 12845+A2:2026 Clause G.8.1, G.8.2, G.8.3, G.8.4 (EN p.151)
- TS EN 12845+A2:2026 continuation of Clause G.8.4 and Clause G.8.5 with its NOTE (EN p.152)
- TS EN 12845+A2:2026 Table 4 (EN p.38)
- TS EN 12845+A2:2026 Table 5 (EN p.39)
- TS EN 12845+A2:2026 Clause 7.2.3.3 (EN p.37)
- TS EN 12845+A2:2026 Clause 5.2 (EN p.30)
- TS EN 12845+A2:2026 Annex P (EN p.164)
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Download MEP Calc on the App StoreTS EN 12845+A2:2026 (EN 12845:2015+A2:2026) Fixed firefighting systems — Automatic sprinkler systems — Design, installation and maintenance; TS EN 12845-2:2025 (EN 12845-2:2024) ESFR and CMSA sprinkler systems. Every figure in this article is taken from the published standard text; clause, table and page references are listed under References. General information only, not a substitute for the standard or for a design review.