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Ecotoxicological information

Toxicity to terrestrial plants

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Description of key information

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:
350 mg/kg soil dw

Additional information

One reliable study is available for this endpoint (Phillips CT and Wentsel RS, 1993). In this study, tests were conducted by ERDEC in 1993 determine if Methyl salicylate, a component of HL simulant, was responsible for the toxicity exhibited by cucumbers (Cucumis sativus) in an earlier test. Seeds were placed in contact with soil treated with the Methyl salicylate and evaluated for effects following 14 days after 50 % emergence of the seedlings in the control group. Endpoints measured were height, fresh and dry weights of the plants. These measurements and observations were compared to those of untreated control plants. Methyl salicylate was tested at 0, 50, 100, 200, 350, and 500 mg/kg dry weight. The test method used was adapted from the U.S. Environmental Protection Agency’s (US-EPA) Environmental Effects Test Guidelines EPA OTS 560/6-82-002 (Early Seedling Growth Toxicity Test).

The Methyl salicylate produced sublethal effects on cucumbers at the 350 and 500 mg/kg levels. The NOEC value deduced from data analysis is 200 mg/kg by weight. The study results indicated that MS was responsible for the effects exhibited by cucumber in the earlier test. No LC50 value has been determined in this study. At the concentrations of 350 mg/kg and 500 mg/kg, significant differences in the height and dry weight of the plants have been determined by statistical evaluation. Based on the comparison of the mean plant height and the mean dry weight between the control and the doses 350 mg/kg and 500 mg/kg, it can be observed that around 20 % of effect is observed at 350 mg/kg and 50 % of effect at 500 mg/kg. As a worst case, the value of 350 mg/Kg dry weight is used for the derivation of the PNEC value.

Natural soil has been used in this study, with the following characteristics:

- % sand: 87

- % silt: 9

- % clay: 4

-% organic matter: 0.3

- CEC (meq/100g): 2.2

Therefore, the organic matter content is lower than the one of the standardised generic environment defined in the ECHA guidance R16, which contains 3.4% of organic matter. Considering that it can be assumed that the binding behavior of the substance is predominantly driven by its log Kow, and that organisms are exposed predominantly via pore water, the bioavailability of the substance should be higher in this natural soil than in artificial standard soil. Consequently, the value of 350mg/kg is considered to be a worst case value.