On 28 September 2026, the Expertbureau Blootstelling Stoffen op het Werk (BSW) will start a feasibility study into current workplace exposure to hydrazine and the feasibility of a new limit value.
The value under assessment is 0.00304 mg/m³ as an 8-hour time-weighted average. The study is carried out at the request of the SER Subcommittee for Occupational Exposure Limits for Substances in the Workplace (SER-GSW). The SER has asked trade associations to inform their members and relevant companies. AeroNL is one of the associations named in its letter.
The link with aerospace
A known application of hydrazine is as rocket fuel and in propulsion systems for space applications, where it is used for propulsion and course corrections of satellites and spacecraft. Hydrazine is also used as a reducing agent in chemical processes, including metal production and electroless nickel plating. The use profile for hydrazine lists the trade associations to which companies working with the substance may belong. The aerospace industry, represented by AeroNL, is one of them.
Hydrazine and the current limit value
Hydrazine is a genotoxic carcinogen for which no safe threshold can be set. It is also a strong skin sensitiser. The current legal limit is 0.013 mg/m³ (0.01 ppm) as an 8-hour time-weighted average, with H notation. This corresponds to the European limit value.
In 2019, the SER-GSW assessed a limit of 0.00304 mg/m³. That value corresponds to the target risk level used in the Netherlands. Following that study, the subcommittee advised a legal limit of 0.013 mg/m³ and indicated that it would assess the limit again at a later stage. The Expertbureau BSW is now examining, on behalf of the SER-GSW, whether the legal limit can be lowered to 0.00304 mg/m³.
The SER-GSW advises the Dutch government on the feasibility of public limit values. The Expertbureau BSW provides independent advice on the practical feasibility of limit values for hazardous substances.
Input from practice
Not all applications, processes and sectors can be fully derived from public sources, which makes input from practice important. Companies that supply information should preferably reflect their sector and must be able to provide representative data. The information concerns exposure data and the measures available to control exposure.
Kick-off meeting on 28 September
The Expertbureau BSW is holding a kick-off meeting at the SER in The Hague on Monday 28 September at 15:30. The meeting is intended for companies, trade associations and experts who will carry out an exposure study for hydrazine or are considering doing so. Expertbureau BSW will explain the procedure, deadlines, required information, and the assessment framework.
To register, email secretariaat@expertbureaubsw.nl, stating your name and the name of your organisation. Questions about the study can be sent to the same address.