Companies are failing to provide the safety data required by Europe’s sweeping chemicals law REACH (registration, evaluation, authorization and restriction of chemicals), according to a study for the Centre for Alternatives to Animal Testing at the University of Konstanz in Germany.

The research looked at 400 documents drawn up by companies and detailing toxicity data for the chemicals they produce. REACH requires companies to produce these documents. The study found that “most” didn’t meet the requirements for providing safety data set by the European Chemical Agency (ECHA) — the REACH regulator based in Helsinki, Finland. In particular, documents lacked adequate data on the toxic effect of chemicals on reproduction and embryo development, the research found.

For example, nearly half the documents were found to have missing or inconclusive evidence of chemicals’ toxicity on embryo development. But in only around 11% of documents did companies propose conducting new tests to fill these gaps.

The study was led by Costanza Rovida, a consultant chemist based in Varese, Italy, and will be published in the journal Alternatives to Animal Experimentation.

We exclusively reported the preliminary results of the study in July (see ‘Data gaps threaten chemical safety law’). At that time, Jukka Malm, director of regulatory affairs at the ECHA, told Nature in an interview that “industry has not taken full responsibility for the quality of data”.

Rovida’s team also uncovered that companies had conducted a handful of illegal animal tests. All new animal tests must receive approval from ECHA before being carried out, but the research found that 24 tests were carried out after the law came into force but without regulatory approval.

The aims of REACH — to improve knowledge of chemical safety while reducing the number of animals used in tests by promoting alternative methods — could be in jeopardy, the study warns.

It suggests that up to 1.6 million animals may be used in tests to assess reproductive and development toxicity, which the team says is “very high”. But proposals for alternative in vitro tests in the documents are “completely absent”, the study finds.