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Ecotoxicological information

Toxicity to terrestrial plants

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In Annex X of Regulation (EC) No 1907/2006, it is laid down that toxicity tests with terrestrial plants shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on terrestrial plants. According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or is assessed to be a PBT or vPvB. The hazard assessment of L-tryptophan reveals neither a need to classify the substance as dangerous to the environment, nor is it a PBT or vPvB substance, nor are there any further indications that the substance may be hazardous to the environment. According to reliable study results, L-tryptophan is considered to be rapidly degraded in the environment and the bioaccumulation potential is regarded to be insignificant. In two studies it is reported that germination of lettuce and mung bean were not affected by L-tryptophan concentrations up to 0.2 g/L (lettuce: 72 h EC50>2 g/L; mung bean: NOEC>0.2 g/L). Based on these findings a low toxicity of L-tryptophan to terrestrial plants is to be expected. Moreover, L-tryptophan is considered as a important precursor of plant growth regulator. Therefore, the performance of further studies according to e.g. OECD Guideline 208 is assumed to be not justifiable.