The CAAT in this instance, being the Center for Alternatives to Animal Testing. See, scientists can be funny too.

The numbers

The European Union’s Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulation, which came into force in 2008, emphasised that “before (proposing) additional animal testing, use of all other options should be considered. It is important to emphasise that testing on vertebrate animals must only be conducted or proposed as a last resort”.

A recent analysis (Knight et al., 2023) has reported that since 2009 about 4.2 million laboratory animals will have been used for REACH testing of just two in vivo mammalian toxicity endpoints: developmental and reproductive toxicity (DART) and repeated-dose toxicity (as shown in the table below). These systemic endpoints are responsible for 92% of the total animal count, with developmental and reproductive toxicity studies comprising the overwhelming majority.


Total animals used/pending

Developmental and Reproductive Toxicity


Repeated-dose toxicity


Pending DART and repeated-dose tests




Other endpoints, including acute and chronic toxicity, genotoxicity and carcinogenicity, account for about 400,000 animals involved in REACH testing. But how do these figures compare to previous estimates?

What the scientific community are doing

It has been estimated that from 1994 – 2008 (before REACH came into force) 54.4 million animals were used for testing in the EU (Rovida et al., 2023), while an ECHA press release in 2009 suggested that the number was as high as 141 million animals. Compare that to the figures from 2009 – 2023, totalling 4.5 million (including pending tests), it is clear that there has been a marked decrease in the number of animals arising from REACH testing which, in part, reflects the drive for alternative testing methods. But more can be done to drive these numbers down.

There are several New-Approach Methodologies (NAMs), including read-across, (Q)SAR, in vitro testing and ‘omics, which are helping to reduce the number of in vivo tests being conducted. Read-across is a widely used tool in hazard and risk assessment which can, in principle, be used to fill data gaps for any toxicity endpoint, but is especially useful for predicting effects of the “higher tier” endpoints like the resource-intensive developmental and reproductive toxicity and repeated-dose toxicity studies and, as such, offers perhaps the greatest opportunity to significantly reduce the number of animals used for testing. Although promoted as an “accepted” approach to avoid in vivo tests in REACH guidance, it has been reported that of the many dossier registrations relying on read-across arguments, most – a disappointing 75% – have been rejected by ECHA during REACH compliance checks.

So, how can we help?

Bibra are experts in employing and justifying NAMs, including read-across and (Q)SAR, in a Weight-of-Evidence (WoE) approach. Get in touch to find out more about our REACH services and how we can help!


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