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Sweden proposes reprotox classification for silver zinc zeolite

Sweden has submitted a harmonised classification and labelling (CLH) proposal to Echa for silver zinc zeolite. The categorisation proposed, which includes toxic for reproduction, could make the substance subject to the exclusion criteria under the biocidal products Regulation (BPR), leading to an EU-wide ban of its use in biocidal products.

The Swedish Chemicals Agency (Kemi) is currently conducting an assessment on the use of eight different silver substances, including nano forms, as biocidal active ingredients as part of the ongoing review programme (GBB May 2014). Silver zinc zeolite is the first of these substances the agency has submitted a draft Competent Authority Report (CAR) for.

Kemi proposes the following classifications for silver zinc zeolite:

  • carcinogenicity category 2;
  • toxic for reproduction category 1B;
  • skin irritation category 2;
  • STOT RE 2;
  • eye damaging category 1; and
  • aquatic chronic category 1.

Having received the proposal, Echa will carry out an accordance check. In due course, stakeholders and member states will have the opportunity to contribute to a public consultation on the proposal. Echa's Risk Assessment Committee (RAC) will then develop an opinion based on the dossier submitted and take into account additional information provided. 

Industry is likely to submit opposing comments during the consultation. The European Silver Task Force says it will challenge the proposal, warning of “unintended consequences for silver” if the classification is confirmed by the RAC.

The dossier for silver zinc zeolite was submitted under the biocidal products Directive (BPD), when the exclusion criteria did not apply. Industry says it should have the opportunity to address these new criteria with new data. “The dossier was prepared following the rules of the  BPD, and therefore in agreement with procedures in place at that time” says Silver Task Force spokesperson, Koen van Maldegem. “We believe that new data can resolve questions regarding classification that result in exclusion and thereby avoid the need for Kemi to propose such a restrictive and overly conservative assessment.”

The dossier is very complex, Mr van Maldegem adds. The silver ion is the active entity, and of course is common to all forms of silver, whether biocidal or not. This is why industry developed a common dossier for all eight silver forms, under the BPD. “It would be absurd if the classification ends up being applied to silver in general, simply as a consequence of rigidly applying the rules of the BPR. The implications would be enormous,” says Mr van Maldegem.

According to Kemi, the conclusion to suggest a classification for reprotoxicity was “a relatively clear cut case”. “Of course study results can always be interpreted differently,” says senior scientific officer, Ulrike Frank. “We looked at the available reprotoxicity study very carefully and came to our conclusion on this basis.”

Whether the assessment in hand will have an impact on the draft CARs for the other substances mainly depends on the availability of further studies, says Ms Frank: “If no other material is available we will probably do a read-across,” she says. “If we have other results – which is the case for a few of the other substances – then we won't, of course."

The next substance on Kemi's agenda is silver nitrate. The other six are:

  • elemental silver;
  • silver chloride adsorbed into titanium dioxide;
  • silver sodium hydrogen zirconium phosphate;
  • silver zeolite A;
  • silver phosphate glass, notified as silver-zinc-aluminium-boron-phosphate glass; and
  • silver borosilicate glass.

Vanessa Zainzinger


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