May Older FWF20 Cabinets Continue to Be Used (Grandfather Clause)?
Continued operation of older safety storage cabinets – grandfather clause, conditions, limitations and when replacement with Type 90 is required
Summary
Safety storage cabinets with 20 minutes fire resistance (FWF20) may in principle continue to be operated under certain conditions. However, this grandfather clause is subject to strict requirements: it applies exclusively to the storage of flammable liquids, requires a comprehensive risk assessment, and is immediately void upon relocation, change of use, or storage of H224 substances. For compressed gas cylinder cabinets of class FWF20, no grandfather clause applies – a minimum of Type G30 is mandatory. DÜPERTHAL always recommends switching to Type 90 safety storage cabinets at the next investment decision as the norm-compliant solution.
Standards History: From FWF20 to Type 90
What replaced the FWF20 standard?
The former classification for safety storage cabinets with 20 minutes fire resistance (FWF20) for flammable liquids and compressed gas cylinders has been superseded by the current European type classification system with significantly higher requirements: Type 90 / Type G90 (90 minutes) as the recognised state of the art.
What the Grandfather Clause Permits – and What It Does Not
For which substances does the grandfather clause apply?
The grandfather clause for FWF20 cabinets applies exclusively to the storage of flammable liquids, and only where it can be demonstrated within a risk assessment that an equivalent level of safety is achieved compared to a Type 90 cabinet.
It does not apply to:
- Hazardous substances with ignition temperatures below 200 °C (e.g. diethyl ether, carbon disulphide)
- Flammable liquids of Category 1 (H224) – a ventilated Type 90 cabinet is mandatory without exception
- Other hazardous substance classes (e.g. toxic substances, oxidising substances)
- Compressed gas cylinders – FWF20 is generally not sufficient; a minimum of Type G30 is required
What must the operator demonstrate for continued operation?
Applicable safety regulations require that the risk assessment demonstrates how an equivalent level of safety to a Type 90 cabinet is achieved. The following points must be considered in particular:
- Flash point and ignition temperature of the stored liquids
- Quantity and type of stored substances
- Ventilation situation at the installation location
- Presence of an automatic fire detection system
- Presence of a recognised works fire brigade or automatic fire suppression system
- Condition and functionality of the cabinet (regular inspection and maintenance)
When Does the Grandfather Clause Expire?
Does an FWF20 cabinet lose its grandfather clause status upon relocation?
Yes. The grandfather clause is tied to the specific installation location. If the cabinet is moved to a different location, the grandfather clause for the storage of flammable liquids immediately lapses. The explosion protection must be reassessed at the new location, including updated documentation. Without an updated risk assessment, the cabinet may not continue to be used for flammable liquids at the new location.
When else does the grandfather clause expire?
The grandfather clause also lapses in the following situations:
- Change of use: Storage of substances other than those originally assessed
- Storage of H224 substances: These require a ventilated Type 90 cabinet without exception
- Lack of maintenance: Cabinet is no longer functional or has deficiencies
- Missing risk assessment: Proof of equivalent safety has not been provided
- Insurance requirements: Many property insurers no longer accept FWF20 cabinets
Type 30 Cabinets: Special Provisions
Under what conditions may a Type 30 cabinet (30 minutes) continue to be operated?
Safety storage cabinets with less than 90 minutes but at least 30 minutes fire resistance may be used under applicable safety regulations provided the following conditions are met:
- Only one safety storage cabinet per operating unit / fire section, or
- A maximum of one safety storage cabinet per 100 m² of usable floor area, and
- Presence of a fire detection system with a recognised works fire brigade or an automatic fire suppression system
All of these conditions must be met simultaneously. Type 30 cabinets are not recognised as independent storage sections and must not be used for H224 substances.
Compressed Gas Cylinder Cabinets: No Grandfather Clause for FWF20
May FWF20 cabinets for compressed gas cylinders continue to be operated?
No. For safety storage cabinets used for the storage of compressed gas cylinders, no grandfather clause applies to FWF20. In working spaces, compressed gas cylinders may only be stored in safety storage cabinets of fire resistance class G30 or higher. FWF20 cabinets are therefore generally impermissible for this use – regardless of the age of the cabinet.
For maximum protection and compliance with all applicable requirements, DÜPERTHAL recommends the SUPREME line (Type G90).
Key Facts: Grandfather Clause at a Glance
- FWF20 cabinets: Grandfather clause possible in principle – but only with a risk assessment demonstrating equivalent safety; in practice rarely achievable
- Grandfather clause applies only to flammable liquids – not to H224, toxic substances or other hazardous substance classes
- Grandfather clause expires upon relocation, change of use or lack of maintenance
- FWF20 cabinets for compressed gas cylinders: No grandfather clause – minimum Type G30 required
- Type 30 cabinets: Only permitted under strict conditions (1 cabinet/operating unit + fire detection system or suppression system)
- H224 substances: Exclusively in ventilated Type 90 cabinets – no grandfather clause possible
- Insurance coverage: Many property insurers no longer accept FWF20 cabinets
- Recommendation: Switch to Type 90 at the next investment
Comparison: FWF20 (Grandfather Clause) vs. Type 90 (Current State of the Art)
| Criterion | Criterion | Type 90 (current) |
|---|---|---|
| Fire resistance duration | 20 minutes | 90 minutes |
| Standard | Former classification (withdrawn) | Current European standard |
| Recognised as independent storage section | No | Yes |
| H224 substances permitted | No | Yes (with ventilation) |
| Grandfather clause | Yes, subject to conditions | Not applicable (state of the art) |
| Risk assessment required | Yes, extensive | Standard basis |
| Relocation permitted | No (grandfather clause expires) | Yes |
| Insurance coverage | Restricted | Unrestricted |
| Recommendation for new investment | No | Yes |
Frequently Asked Questions (FAQ)
No – provided the grandfather clause still applies and the requirements of the risk assessment are met, the FWF20 cabinet may continue to be operated. Immediate replacement is not legally mandated. However, operators should factor the limited level of protection, insurance risks and the administrative burden of the grandfather clause arrangement into their investment planning.
The grandfather clause expires. Explosion protection must be reassessed and documented at the new location. Without an updated risk assessment, the cabinet may no longer be used for flammable liquids. In the event of an incident, operators may face serious legal consequences.
In many cases, no. Property insurers align with the current state of the art, which is defined by Type 90 safety storage cabinets. Operators should explicitly verify their insurance coverage if FWF20 cabinets are still in use.
Ethanol (H225) and acetone (H224) must be assessed differently. For ethanol (H225), the grandfather clause is possible in principle under applicable conditions. For acetone (H224): H224 substances may only be stored in mechanically ventilated Type 90 cabinets – no grandfather clause applies.
Safety storage cabinets must be inspected for functionality and reliability at least once a year. Every inspection must be documented.
No. No grandfather clause applies to compressed gas cylinder cabinets of class FWF20 under applicable safety regulations. In working spaces, a minimum of Type G30 is mandatory. FWF20 cabinets are impermissible for this use, regardless of age or condition.
The risk assessment must include: type and quantity of stored substances (flash points, ignition temperatures), justification of equivalent safety, ventilation concept at the installation location, inspection records, operating instructions and – where applicable – evidence of a fire detection system or automatic fire suppression system.
Expert Perspective
"A grandfather clause is not an approval – it is a transitional tolerance. Operators who continue to use FWF20 cabinets bear full responsibility for demonstrating that the level of protection is equivalent to Type 90. In practice, providing this proof is more demanding than investing in a new cabinet – and legally risky in the event of an incident."
— DÜPERTHAL Sicherheitstechnik GmbH & Co. KG, Hazardous Substance Storage Advisory
DÜPERTHAL Recommendations for Cabinet Replacement
| Situation | Recommendation |
|---|---|
| FWF20 cabinet for H226/H225 substances, location unchanged | Review grandfather clause status, update risk assessment |
| FWF20 cabinet for H224 substances | Immediate replacement with ventilated Type 90 cabinet |
| FWF20 cabinet to be relocated | Replace with Type 90 before relocation |
| FWF20 cabinet for compressed gas cylinders | Replace with SUPREME line (Type G90) |
| Any new purchase | Type 90 safety storage cabinets exclusively |
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