« Committee says two genotox tests can be conducted on the same animals
Echa’s Member State Committee (MSC) has for the first time requested that a registrant conduct two in vivo tests on the same animals.
At its meeting last week, the the committee agreed a compliance check on the dossier for n-isopropyl-n’-phenyl-p-phenylenediamene.
In order to fill a data gap in the dossier, it decided the registrant must conduct two in vivo assays for genetic damage, and that it should combine these and use the same animals.
• the comet assay OECD TG 489; and
• the micronucleus assay OECD TG 474. in order to fill a data gap in the dossier, but that it should combine these assays and use the same animals.
“This is a very good way of optimising test procedures and was important from an animal welfare point of view,” MSC chairman Watze de Wolf said. The decision will support one of the chief aims of REACH: is to reduce, refine and replace animal use in chemical testing.
The committee also agreed the technical details of a testing proposal examination on the dossier for 3-methoxy-3-methylbutan-1-ol, and discussed a compliance check on the dossier for 2,2’-dimethyl-4,4’-methylene-bis(cyclohexylamine). On the latter, the committee agreed not to pursue – at this moment under this compliance check – the proposals for amendment regarding the information requests for simulation degradation testing.
The MSC also considered two draft decisions on substance evaluations:
• 3,3’-dimethylbiphenyl-4,4’-diyl diisocyanate. Known as TODI, the French competent authority is looking at this.
It was listed for substance evaluation due to concerns that it is a potential CMR (carcinogen, mutagen or reproductive toxicant) and a potential sensitiser with possible persistent, bioaccumulative and toxic (PBT) properties.
It is used as a monomer in polyurethane manufacture under highly controlled conditions. There is potential for the formation of a degradation product, known as TODA, which has a harmonised classification as a 1B carcinogen. TODA, and potentially other degradation products stemming from TODI, might also be released from the polymer or during use of the finished articles.
To determine whether this substance can be safely managed, the committee decided to ask the registrant for further information on human exposure to the substance and degradation products. The competent authority will then review the situation and determine whether further consideration by the committee is necessary.
• di-tert-butyl 3,3,5-tri-methylcyclohexidene diperoxide. This is being looked at by the German competent authority.
It is has a wide range of uses in adhesives, sealants and coatings, but has potential PBT or very persistent very bioaccumulative (vPvB) properties.
The substance evaluation showed there is significant uncertainty around its water solubility, and therefore an existing bioaccumulation study may not be sufficiently reliable. Performing a simulation degradation test in surface water may also not be technically feasible. Hence the committee decided to request a water solubility study.
The committee also asked the registrant to perform two simulation degradation tests sequentially. If the first test in surface water turns out to be impossible, the second one in sediment can be carried out immediately.
At the meeting the MSC appointed a rapporteur, co-rapporteur and established a working group for the update of the Community Rolling Action Plan (Corap) in March next year. The rapporteur and working group will prepare the draft Opinion on the Corap, which the committee will discuss and agree upon in meeting in February. »
Article by Philip Lightowlers: https://chemicalwatch.com/37382/echas-msc-pushes-optimised-animal-use-in-testing-proposals
MSC meeting 43 agenda : http://echa.europa.eu/documents/10162/13578/msc_43_agenda_en.pdf
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