Establishing validated concentration limits for ecotoxicological tests HP 14 for waste
Résumé
The hazard properties of waste in Europe are defined in the Commission Regulation (EU) N° 1357/2014 of 18 December 2014 replacing Annex III to Directive 2008/98/EC of the European Parliament and of the Council on waste and repealing certain Directives, excepted for the most frequent one, HP 14 ‘Ecotoxic’ (Hennebert et al. 2014). The Directorate General Environment launched in May, 2014 a “Call for tenders ENV.A.2/ETU/2014/0023r - Study to assess the impacts of different classification approaches for hazard property “H 14” on selected waste streams”, HP 14 being calculated from the chemical composition of the waste with different methods. The results of this study are not published at the time of this abstract. An independent study on 120 wastes has ranked the four calculation methods that are proposed (Hennebert et al. 2016) and has tested a 5th variant with multiplying factors for the most ecotoxic substances (M-factors of the CLP), with 80% matching with the European List of Waste. For these calculation methods, the speciation of the elements into substances must be hypothesized. Ecotoxicological tests could provide a straightforward classification without hypothesis of speciation. It is accepted in chemical regulation that results of tests overwhelm results of calculations. The design of the toxicity tests follows a dose/response or dilution approach, meaning that the waste (eluate or solid) is mixed with different amount of a control substrate (e.g. culture medium of reconstituted water or artificial soil), and that a biological parameter is measured for each dilution. The results of these tests can be expressed as ECx values (concentration of eluate or solid in the mixture with the control substrate producing a biological effect of x %, namely 20% or 50% of growth, mobility, reproduction, etc.). An EC50 of 8% means that a dilution of the culture media with 8% of waste produces a reduction of 50% of i.e. mobility. Preparation of eluates (liquid/solid ratio = 10 l/kg dry matter, 24h) and mixtures of waste with control substrate are carried out according to EN 14735. An aquatic and terrestrial tests battery with bacteria, plant and invertebrate animal is proposed by Pandard and Römbke (2013), from a previous proposal of Ökopoll (2008). The test battery can be operated stepwise, and stopped if one test result is lower than its proposed concentration limits. In France a previous proposal of 1997 is used, sometimes in a modified version in 2006 (Pandard et al 2006). Concentration limits of 10% for acute tests and 1% for chronic tests are proposed but without validation, and unsatisfactory results. If one of the ECx values measured by the tests for a given waste is below its concentration limit, the waste is classified as hazardous. The waste is considered as non-hazardous only if the results of all ECx values are above their respective concentration limits. Hence, a validated concentration limit (classifying the waste hazardous or non hazardous) for each test should be the lowest ECx value measured with a panel of non ecotoxic waste (by the European List of Waste taken as reference). Simultaneously, it must be checked with a panel of ecotoxic waste that at least one ECx is below the proposed concentration limits. The results of this original method will be presented in the paper.