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Ecotoxicological information

Toxicity to terrestrial plants

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Description of key information

m-cresol: EC50 (14 d) = 233 mg/kg d.w. standard soil on Lactuca sativa (OECD TG 208)
o-cresol: EC50 (14 d) > 242 mg/kg d.w. standard soil on Lactica sativa (OECD TG 208)

Key value for chemical safety assessment

Additional information

o-cresol and m-cresol

The toxicity of o-cresol and m-cresol to lettuce (Lactuca sativa) was examined by Hulzebos (1993) according to OECD guideline 208. The organic matter of the two soil types used in the experiment was given to range between 1.4% and 1.8%. The weight of the above-ground biomass was measured after 7 and 14 days. After an exposure period of 14 days an EC50 of >100 mg/kg dw soil was obtained for o-cresol and an EC50 of 96 mg/kg dw soil was obtained for m-cresol. According to TGD (EU 2003) these values were normalised to a standard soil containing 3.4% of organic matter, resulting in a corrected EC50 of >242 mg/kg for o-cresol and a corrected EC50 of 233 mg/kg for m-cresol. The authors state that during the test period, the concentrations of most phenols in soil dropped to less than 20% of the initial concentrations.

 

p-cresol

The effect of p-cresol on the germination of lettuce fruit (Lactuca sativa) was tested under laboratory conditions (Reynolds, 1978). After an exposure period of 72 h an EC50 of 122 mg/L was determined.

The scope of the terrestrial effects assessment under the adopted REACH regulation is restricted to soil organisms in a narrow sense and does not actually include adverse effects on soil functions that are only indirectly linked to the biota in soils. This test was designed assessing the influence of p-cresol on germination and growth on moist filter paper or agar treated with the substance. As no soil was used standardisation of soil effect data to given soil parameters is not possible. Further, converting the results to an appropriate dimension is not applicable. Therefore the result should not be used for the hazard assessment. Nevertheless, the obtained effect values indicate that p-cresol is of low toxicity to terrestrial plants.

long-term toxicity to terrestrial plants

Long-term toxicity tests on plants are not available. Based on the exposure assessment there is no unacceptable risk of cresols to the soil ((PEC/PNEC < 1) and thus, long-term studies on terrestrial plants do not need to be conducted.