KANBrief 2/25
Numerous forms of safety storage cabinet are available on the market which according to their manufacturers are intended to allow safe storage and charging of the lithium-ion batteries (LIBs) now used in many types of battery-powered tools. To date, neither the legislator nor the German Social Accident Insurance Institutions have issued provisions binding in Germany for such storage cabinets. A product standard for safety storage cabinets would be one means of ensuring that LIBs are stored and charged safely.
Provided they are used as intended, lithium-ion batteries are considered safe. However, damaged or defective LIBs can vent gas or undergo thermal runaway, particularly during charging. These processes can give rise to fire and explosion hazards, and also hazards presented by the release of hazardous substances. Safety storage cabinets that are tested and in some cases even GS-certified for the safe storage and charging of LIBs and are intended to protect workers against these hazards are now available on the market in numerous variants and configurations. In practice, this leads to two problems:
Problem 1: The German Product Safety Act (ProdSG) serves as the framework for safety requirements for the design, construction and equipment of safety storage cabinets. Beyond the ProdSG, no specific state or accident insurance regulations exist in this area. These safety storage cabinets constitute work equipment and as such must satisfy Annex I of EU Directive 2009/104/EC concerning the minimum safety and health requirements for the use of work equipment by workers at work, which has been transposed into German law by the German Ordinance on industrial safety and health (BetrSichV). The BetrSichV is addressed to the employer, not to the manufacturer of an item of work equipment. As the employer may not use work equipment that is not safe, the BetrSichV places only indirect requirements upon the manufacturer of a safety storage cabinet.
Problem 2: The safety storage cabinets are tested against a number of different test specifications (including EN 14470-1 (EN 14470-1 Fire safety storage cabinets – Part 1: Safety storage cabinets for flammable liquids), the German test specification EK5/AK4 22-01, VDMA specification 24994 (2024-08 Test requirements for fire-protection storage cabinets for lithium-ion batteries in the case of thermal runaway). These are based essentially on the fire hazards in the event of a thermal runaway, and do not consider explosion hazards, or health hazards arising from the release of hazardous substances. They also differ, in some cases considerably, in the nature and scope of the tests (e.g. duration of fire resistance, smoke tightness). This makes it difficult for the operator to determine whether the requirements for safe storage and charging in these cabinets are met.
These problems could be resolved by a standard for cabinets for the safe storage and charging of LIBs. Such a standard would describe the state of the art for the design, construction and equipment requirements for the cabinets, and set out test procedures for them.
In spring 2023, committee NA 055-02-02, Lab furniture, of the DIN Standards Committee Laboratory Devices and Installations (FNLa) launched the initiative to add a Part 3 to the EN 14470 series of standards on fire safety storage cabinets. The new part of the series was to address fire-resistant safety storage cabinets for rechargeable energy sources. At around the same time, the standards committee NA 060-20-01, Safes and strongrooms, of the DIN Standards Committee Mechanical Engineering (NAM) began work on the VDMA specification: Test requirements for fire-protection storage cabinets for lithium-ion batteries in the case of thermal runaway. The draft of this specification was published in August 2023. Following expiry of the deadline for comments, experts from the two standards committees and representatives of the German Federal Institute for Materials Research and Testing (BAM) and the DGUV drew up a final version of this specification, which was published in August 2024. It contains test requirements for resistance to fire both inside and outside the cabinet, but no further tests regarding gas or smoke tightness. Recommendations for the design, construction and equipment of safety storage cabinets were also added to the specification.
Since then, NA 060-20-02 has submitted an application for a European standardization project in CEN/TC 263, Secure storage of cash, valuables and data media. The application was approved in December 2024. Based on the VDMA specification, a European standard is to be developed that includes relevant test requirements for safety storage cabinets for LIBs. Work on the draft standard in CEN/TC 263 WG 2, Fire resistance, will begin in June of this year. Cooperation between the responsible standards committees of FNLa and NAM in the development of the VDMA specification is to be continued in the development of the European standard. Experts from both standards committees will therefore be involved in drafting the standard in WG 2 of CEN/TC 263. Ideally, it should be determined whether further tests of protection against explosion and against the release of hazardous substances should be added to the standard. It is also unclear whether the standard’s scope will be extended to include requirements for the design, construction and equipment of the safety storage cabinets.
Owing to the work on VDMA specification 24994, NA 055-02-02 initially halted its own work on a product standard for safety storage cabinets for LIBs. As it cannot be foreseen at this time to what extent the VDMA specification will be developed further into a European standard containing requirements for both the product and the tests, NA 055-02-02 has decided to submit a corresponding international standardization project on safety storage cabinets to SC 9, Laboratory furniture, of ISO/TC 48, Laboratory equipment. At the last meeting of SC 9 in ISO/TC 48, the decision was taken to set up a Battery Cabinets working group to develop an application for standardization for this purpose and an initial draft of a product standard.
In whichever direction standardization takes us: ultimately, the standards should ensure that a safe product can be manufactured for the charging and storage of LIBs and that this product can also be operated safely.
Dr. Andreas Kleineweischede, German Social Accident Insurance Institution for the raw materials and chemical industry (BG RCI)
andreas.kleineweischede@bgrci.de