Diisocyanates are – together with polyols – the main building blocks of polyurethanes. The two diisocyanates used in the production of flexible polyurethane foam are TDI (Toluene diisocyanate) and – to a lesser extent – MDI (Methylene diphenyl diisocyanate).
Diisocyanates – when not handled properly – can cause health issues, such as skin or eye irritation and occupational asthma. To protect workers in the European Union (EU) from these health hazards, on 13 February 2023 the European Commission has proposed binding Occupational Exposure Limits (OELs) for diisocyanates, thus establishing a minimum level-playing field across the EU.
The Commission proposes an overall time weighted average (TWA) occupational exposure limit of 6 µg NCO/m3 and a short-term exposure limit (STEL) of 12 µg NCO/m3. A transitional value of 10 μg NCO/m³ with an associated STEL equal to 20 μg NCO/m³ should apply until 31 December 2028.
Period | Type | µg NCO/m3 | ppb |
|---|---|---|---|
Until 31 December 2028 | STEL | 20 | 5.8 |
Until 31 December 2028 | TWA | 10 | 2.9 |
From 1 January 2029 | STEL | 12 | 3.5 |
From 1 January 2029 | TWA | 6 | 1.7 |
The proposed OELs were developed over the last years by the European Chemicals Agency (ECHA) on the basis of scientific evidence on the health effects of diisocyanates and following the Opinion of employers, trade unions and EU Member States in the Advisory Committee on the Health and Safety at Work (ACSH).
Of course, occupational exposure limits for diisocyanates are not new. They already existed in some Member States at various levels but never for all diisocyanates. The proposal by the Commission is therefore a significant step towards harmonisation of rules, even though Member States remain free to adopt lower limits if they wish to do so.
The proposed OELs will be legally binding in all EU Member States, and employers will be required to take measures to ensure that workers are not exposed to concentrations above these limits.
What is the European flexible PU foam industry’s view on the OELs?
As mentioned above, the OELs as proposed by the European Commission have been extensively discussed between employers, trade unions and EU Member States in the ACSH. While there may be significant adaptations required in some factories and therefore costs involved, we believe that the transition period leading to the final limits provides industry with suitable time to adapt. A level playing field between all EU countries is much better than the current coexistence of very different rules. The science-based harmonised OELs should allow a high level of worker protection in the EU, especially in combination with the already adopted REACH Restriction for Diisocyanates, that imposes adequate training of workers handling the substances. As much effort was invested to create harmonised rules for Europe, we call on EU Member States to refrain from adopting their own measures on individual OELs for diisocyanates going forward.
What will EU flexible PU foam producers have to do to comply with the proposed OELs?
There is no one-size-fits-all situation there. Some limited number of factories may already comply with the new OELs, while in others investments will be needed. Generally, compliance with the new OELs will require a combination of further enclosure of production lines, enhancement of existing ventilation systems, and – where required – use of personal protective equipment for critical tasks.
What are the next steps?
The proposal of the European Commission will now undergo the normal legislative procedure involving the European Parliament and Council of the EU (representing Member States). Considering that the OELs proposed by the Commission were supported by employers, trade unions and EU Member States in the ACSH, we call on both co-legislators to adopt the proposal as is.
Want to learn more?
If you want to learn more about the safe handling of diisocyanates (as well as polyurethane foam in general), follow these links:
