Definition
An endocrine disruptor is a substance that interferes with the hormone system. Hormones act as chemical messengers that regulate growth, metabolism and reproduction, and a disruptor can mimic, block or alter that signalling. Effects can appear at low doses and may show up long after exposure, which makes these substances harder to assess than many acute hazards.
Why it matters
Endocrine disruption does not fit neatly into the CMR or PBT boxes, so it is handled under a separate route. A substance can be identified as a substance of very high concern on the grounds of equivalent concern, meaning the worry it raises is comparable to that of a CMR or PBT substance. That status brings it onto the Candidate List with the usual communication and notification duties.
Equivalent concern is the legal hook that lets endocrine disruptors become SVHCs even when they do not meet the CMR or PBT criteria.
Examples
Well-known examples include bisphenol A, used in polycarbonate and epoxy resins, and several phthalates used as plasticisers. Both have drawn regulatory attention partly because of their endocrine activity.
Note: general educational information, not legal advice. Check the official source before relying on it.