Subject: Meeting on biological availability in the framework of CLP, Brussels, 27 April 2015; comments by CA AT

Dear colleagues,

unfortunately, we were not able to take part in the meeting on biological availability in the framework of art. 12 (b) of the Regulation N° 1272/2008 on Classification Labelling and Packaging of substances and mixtures on 27th April 2015. The discussion on the use of date on bio-availability in substance classification is very important, and we must say that the discussion within Austria is far from conclusive. We generally believe that it is premature to make firm political decisions in the framework of bioavailability. We would like to provide below some thoughts which highlight the problem rather than provide a solution.

On the other hand, we are well aware of the concerns, especially from the metal recycling industry, about the classification of bulk lead as reprotoxic 1A with a specific concentration limit of 0,03%. The Austrian industry has provided information which demonstrates the potential adverse economic consequences of such a decision. Given that the scientific discussion concerning the use of bio-availability in classification is still ongoing we believe that a very pragmatic solution must be found for the present case. Before this background we favour the suggestion made by some Member States to limit the classification in the current decision step to metal powder below a certain corn size, 1 mm being a realistic compromise, and to postpone the decision on the classification of lead in bulk form until a scientifically acceptable approach including an appropriate procedure has been established.

With that said, we wish to make the following observations on the issue of bio-availability in classification:

  1. We agree with some Member States that it is not at all clear as to whether article 12 of CLP applies only to self-classifications rather than to harmonised classification. So, it remains unclear if the reference to article 12 made by EUROMETAUX[1], is legally sound.
  2. The CLP definition for alloys refers to a macroscopically homogenous material. It needs to be clarified to which extent surface treated metals, e.g. a metal A coated with another metal B, actually can be considered as being covered by this definition. This is important because such bulk metals will behave quite specially if exposed to an aqueous solution (seemingly no dissolution of metal A coated by metal B will be observed in a usual dissolution-transformation protocol).
  3. In its paper EUROMETAUX refer to alloys which are included in a matrix or complex structure or which have specific conditions at the surface. It is not clear as to whether EUROMETAUX actually refers to alloy samples which fulfil the CLP definition of alloys.
  4. The derivation of the effective concentration as proposed by EUROMETAUX depends critically on the time scale, especially in cases where the dissolution kinetics is not linear in time. In this case, the bio-accessibility factor becomes time-dependent. The concept as presented by EUROMETAUX does not take account of this aspect.
  5. It seems to us that the reasons for different dissolution kinetics between a reference metal and an alloy containing this metal are mechanistically not well understood. Moreover, the dissolution process may critically depend on the way of agitation as referred to in the UN transformation-dissolution protocol. The agitation may influence the kinetics of the dissolution process which in turn is very important here (see point 4).
  6. It is unclear whether the UN transformation-dissolution protocol developed for environmental testing can actually be simply transferred to human toxicity testing as suggested by EUROMETAUX. Depending of the considered end-point a number of methodological questions need to be solved.
  7. EUROMETAUX admit in their paper that there is currently no generally accepted standard available for measuring the degree of bio-accessibility. Given the questions raised above (and probably a number of other aspects not mentioned here) we feel that it would be very important to establish, if possible, such a standard and to clearly define its scope and applicability before implementing the concept of bio-availability in the classification. The existing ASTM-D5517 standard does in our view not comprise a sufficiently well defined frame.

Finally we would like to state that we agree with EUROMETAUX that a case-by-case decision on the use of bio-availability in classification may lead to discord within the EU and may be an unacceptable burden to both, the affected industry and the enforcement authorities.

Martin Wimmer

CA Austria

Vienna, 27th April 2015

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[1]We refer here to the paper by EUROMETAUX “How can bioelution/bioaccessibility data be used fort he hazard classification of alloys under CLP and GHS?”