Definition
CMR groups three of the most serious hazard categories in chemicals law. A carcinogenic substance can cause cancer. A mutagenic one damages DNA and can cause heritable genetic changes. A substance toxic to reproduction harms fertility or the development of a child. The categories are defined under the CLP Regulation.
Why it matters
A CMR classification is one of the clearest routes into stricter regulation. It is grounds for identifying a substance as a substance of very high concern, which puts it on the Candidate List. It can also trigger a REACH restriction that limits or bans a use outright.
The phthalates controlled under RoHS are CMR substances, which is why they carry strict concentration limits in electrical and electronic equipment.
A CMR finding rarely stays academic. It tends to feed directly into REACH action, from Candidate List entry through to restriction.
Note: general educational information, not legal advice. Check the official source before relying on it.