The REACH proposal defines some chemical as being "of very high concern" to human health and the environment, requesting that they be evaluated as a top priority by the future European chemicals agency in Helsinki.
Substances "of very high concern" are defined as those blamed for causing cancer, genetic mutations or reproductive problems and which tend to build up in the human body and the environment [carcinogenic, mutagenic and reproductive toxic (CMR); persistent, bioaccumulative and toxic (PBT); and very persistent and very bioaccumulative (vPvB)].
However, the European chemicals agency will still be able to authorise these substances in cases where their replacement proves too difficult, too costly or when there are no alternatives. In their first reading on REACH last year, the EU Council of Ministers agreed that the agency would be able to allow the temporary use of these chemicals only under three circumstances:
- their risks for human health or the environment are "adequately controlled"
- the social and economic benefits of the substance outweigh those risks; or
- analysis has shown "suitable alternative substances do not exist"



