The EU Parliament has, after a review, adopted a position on formaldehyde as part of the 3rd wave of revisions to the Carcinogen & Mutagens Directive. The effect of this is, as of now formaldehyde is classified as a class 1b carcinogen, presumed to be a human carcinogen. It therefore now carries the H350 May cause cancer (equivalent to R45) code. As part of this change, the WEL for formaldehyde has been set at a new lower level of 0.3ppm (0.37mg/m3) which will come into effect in 2 years from now.
However, the immediate effect is, that as a carcinogen, formaldehyde exposure needs to be controlled to as low as reasonably practicable (ALARP). This means that even if emissions at your site are at the current WEL of 2ppm, you must look to get the levels lower than that, to the point where it becomes unreasonably practicable to do more. This is detailed in COSHH s7(7).
So what can you do? Ensuring mixers are set and cleaned correctly, that binder mixes are optimised to minimise the quantities of resins/binders needed and good general ventilation may enable emissions levels to be lowered to meet this requirement without too much additional work. If you are using substances containing formaldehyde, you should ensure that air monitoring takes place at each stage of the process, from mixing through to knockout, including during mould coating and casting, to ensure you know what your measured levels are, before undertaking (or reviewing) a risk assessment to determine what additional controls may need to be undertaken.
At present the HSE are not planning on changing EH40 to reflect the new classification or revised WEL, but all businesses using formaldehyde will need to change how they control exposure. Just as a reminder, ALARP takes precedence over any prescribed WEL when dealing with a carcinogen.