HOW AVOIDING OVER-CLASSIFICATION SAVED A CHEMICAL COMPLIANCE STRATEGY

One of the activities that I perform daily, which is anything but routine, is the classification of substances based on test results. Sometimes it can be highly complex, especially when dealing with in-vitro studies, such as substances testing positive for phototoxicity (OECD 498).

The default reaction in these cases is often to over-classify. Out of fear, companies tend to force substances into higher hazard classes, such as Acute Dermal Toxicity or STOT RE, just to “be safe” and avoid regulatory friction.
But over-classifying a substance has major business consequences: it triggers heavier safety data sheets (SDS), transport restrictions, and can completely ruin market positioning.

The technical reality is that CLP currently has a blind spot for standalone phototoxicity and, more generally speaking, for several in-vitro studies. You cannot legally or scientifically force an in-vitro phototoxicity result into Acute Tox or STOT RE criteria. For CLP purposes, the substance remains unclassifiable for this endpoint, meaning risks should be managed through specific PPE and mitigation measures instead.

It is always a case-by-case situation where setting the exact boundaries of the law is crucial to protect both safety and business continuity.