Europa
Concerns and Issues regarding the Review of Silver containing Active Substances by Sweden
Paper presented for the November 2014 CA Meeting
This position paper is presented on behalf of the European BPR Silver Task Force (“STF”) and concerns the review by the Swedish Rapporteur Member State (“RMS”), acting through its agency “Kemikalieinspektionen” (“KemI”), of eight silver containing active substances (“SCAS”)[1] that are supported by the STF member companies[2] in the review program initiated under the Biocidal Products Directive 98/8 (“the BPD”) and continued under the Biocidal Products Regulation 528/2012 (“the BPR”).
Each SCAS is supported by a collective dossier on the silver (Ag+) ion, which is the common active element released by all, and the basis for read-across among SCAS’. This was agreed in 2006 at the beginning of the review between the Commission, Member States and the STF as effectively the only means of conducting the review in a cost/time efficient way. To date, however, only one draft Competent Authority Report (“CAR”) was prepared by Sweden (in May 2012).
The STF has the following serious concerns regarding the review by the RMS:
Summary of concerns
The approach followed by the RMS (1) to require that all uses of SCAS’ in treated articles are approved at the active substance level and (2) to use overly conservative exposure scenarios to identify alleged "major concerns" aimed at prohibiting broad groups of treated articles (especially for consumer products).
As a result, (3) the endpoints set by the RMS which contrast dramatically with those concluded under other chemical regulations (e.g. REACH and plant protection products), where they are either not identified (human toxicology endpoints) or much less conservative (aquatic and terrestrial eco-toxicity endpoints).
(4) The transition from BPD to BPR, requiring addressing specific endpoints for classification as regards potential exclusion or substitution criteria, and the intended extrapolation of the carcinogenicity classification for silver zinc zeolite, in the absence of clear data, to all other SCAS’, which discredits the read-across approach agreed upon under the BPD and ignores the possibility for the STF to address the issues with e.g. additional data.
The STF respectfully asks that this matter is referred without delay to the relevant BPC Working Group, with due account of the requirements to minimize vertebrate testing and to ensure a consistent approach across substances. The delays and inflating review costs make it increasingly difficult for the STF to assume its responsibilities under the BPR notably in terms of data and cost sharing.
1. The exclusion of broad groups of treated articles finds no support in the BPR
The CA meetings of March and September 2014 discussed and endorsed the principles in the "Note on the specific conditions to be set in the approval of active substances in relation with treated articles" that “restrictions of the use of an active substance in treated articles only to uses that have been assessed cannot be justified at this stage”and that:
• “Restrictions concerning the use of the active substance in treated articles shall only be introduced where a major concern is identified.
• In such cases, the approval shall indicate which categories of articles can or, as appropriate, cannot be treated with a biocidal product containing the active substance. (…)
• the description of the use restricted should be sufficiently specific in order that the restriction only applies to those categories of treated articles for which the major concern is identified and relevant.” [3] (underlining added)
Despite this, the RMS maintains that authorization of the treated article uses of SCAS’ should be conducted at substance approval level. It views treated articles as any items that could theoretically be treated with silver and, as a result, applies maximum oral and dermal exposure scenarios in a highly conservative manner (irrespective of whether the exposure scenarios are realistic or relevant to the actual uses of each SCAS), with the consequence that broad groups of silver treated articles will be excluded. Whilst the STF acknowledges the broad concept of the envelope approach, data which is normally only generated at product authorization level is effectively required for active substance review. "One safe use" should be upheld to allow approval of the active substance and specific sub-uses for products should be assessed at subsequent review.
2. Toxicological and ecotoxicological assessments are overly conservative and contrast dramatically with end-points concluded under different chemical regulations
The RMS uses overly conservative assessments to conclude that SCAS’ meet exclusion/substitution criteria and that, allegedly, a "major concern" is identified prohibiting all uses in treated articles. Undue emphasis is placed on the “argyria effect” (pigmentation of tissue and organs) for setting the long term AEL by regarding it as an exclusively toxic effect. The RMS also proposes a Category 1B reproductive toxicity and Category 2 carcinogenicity classification for silver zinc zeolite and intends to extrapolate the carcinogenicity classification to all other SCAS’ (including metallic silver) should it be confirmed by the Risk Assessment Committee (“RAC”) at ECHA. This classification proposal, however, is highly conservative and extrapolation to other SCAS is extreme considering available weight of evidence and negligible human exposure. In contrast, the ongoing REACH assessment of different forms of silver by the Netherlands has so far not identified any of these alleged concerns.
Also the aquatic and terrestrial end-points used by the RMS are highly conservative compared to the REACH and plant protection product evaluations of silver, as is clear from the chart below:
|End-Point |REACH |Plant Protection |Biocide |
|Surface water |HC5 = 0.119 µg/L |NOEC = 0.24 µg/L |NOEC = 0.02 µg/L |
| |species sensitivity analysis based on |deterministic assessment from lowest |deterministic assessment based on |
| |16 species across different trophic |available NOEC for fish |extrapolation from the lowest available|
| |levels |PEC = 0.01 µg/L |LOEC for fish |
| |AF = 3 |TER = 24 |AF = 10 |
| |PNEC = 0.04 µg/L |Annex VI trigger = >10 |PNEC = 0.002 µg/L |
|Sediment |NOEC = 12 mg/kg dw based on Hyalella |Limited data |NOEC = 441 µg/kg dw deterministic |
| |azteca growth effects |Further data not requested based on low|assessment based on Lumbriculus body |
| |AF = 10 |exposure |weight effects |
| |Normalised to 5% organic content to | |dw/ww conversion = 4.6 |
| |give a derived PNEC = 438 mg/kg dw | |AF = 50 |
| | | |PNEC = 1.92 µg/kg ww |
|Soil |HC5 = 3.29 mg/kg |Limited data |NOEC = 0.28 mg/kg ww deterministic |
| |species sensitivity analysis based |Assessment could not be performed but |assessment based on suppression of soil|
| |normalisation of soil ecotox data to EU|not highlighted as a critical area for |carbon respiration |
| |soil types |concern in the EFSA conclusions |AF = 50 |
| |AF = 3 |document |PNEC = 5.6 µg/kg ww |
| |PNEC = 1.10 mg/kg | | |
AF = Assessment Factor
3. The approach followed discredits the read-across agreed upon under the BPD
The RMS' intention to extrapolate alleged CMR classification for silver zinc zeolite, in the absence of clear data, to all SCAS’ discredits the read-across approach agreed under BPD. The BPR mandates that sufficient data must be available to conclude classification to determine exclusion criteria (see, e.g., Articles 6(2), 8(2) and 90(2) BPR), which is not the case unless read-across is more liberally applied. If data are truly lacking to conclude classification following the change in emphasis between the BPD and BPR, the STF should be allowed to address this through, e.g., additional study data.
The September 2014 CA meeting agreed that “in case MSs have to request additional data or decide to request no further data, discussions could take place in the relevant WG of the BPC to ensure consistency in the requirements across active substances”[4].
It is possible, by using a weight of evidence approach and a less conservative stance on the data presented, as has been taken in other reviews, to conclude a realistic classification for all SCAS without recourse to further animal testing. The STF respectfully requests that this is discussed at BPC and a common position applied with due account of the requirements to minimize vertebrate animal testing and to ensure a consistent approach.
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[1] The SCAS are: elemental silver, reaction mass of titanium dioxide and silver chloride, silver nitrate, silver sodium hydrogen zirconium phosphate, silver phosphate glass, silver zinc zeolite, silver copper zeolite and reaction mass of silicon dioxide and silver.
[2] BASF SE, Clariant International Ltd, Dow Europe GmbH, HeiQ Materials AG, Ishizuka Glass Co. Ltd, Milliken Europe BVBA, ProEconomy Ltd, Sanosil AG, Sciessent LLC, Tarn-Pure (IP) plc and Thor GmbH.
[3] CA-Sept14-Doc.6.2, page 4.
[4] CA-Nov14-Doc.2, Draft minutes, 57th meeting of representatives of Member States Competent Authorities for the implementation of Regulation 528/2012 concerning the making available on the market and use of biocidal products, 17-19 September 2014.
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CA-Nov14-Doc.4.7
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