Reaction mass of m-cresol and 2-chloro-m-cresol and 6-chloro-m-cresol

Endpoint summary

Additional information

The relevant data on acute toxicity to aquatic organisms for Preventol KMX and the read across substance 4-chloro-3-methylphenol are summarized in the table below. The read across justification and additional data for m-cresol are attached to the Chemical Safety Report in Annex I. In comparison to the chlorocresols, m-cresol is only a minor component of Preventol KMX. Therefore these data are not considered for the assessment of the acute toxicity of Preventol KMX.

Table 1: Comparison of relevant data on acute toxicity of Preventol KMX and 4-chloro-3-methylphenol

Endpoint	Preventol KMX	4-chloro-3-methylphenol
Short-term toxicity to fish	OECD 203 Danio rerio LC50 (96 h): 6.7 mg/L (mean)	Method: EPA OPP 72-1 Oncorhynchus mykiss LC50 (96h): 0.92 mg/L (geometric mean)
Long-term toxicity to fish	Read across 4-chloro-3-methylphenol	Prolonged tests OECD204/215 Oncorhynchus mykiss 28d NOEC = 0.15 mg/L (mean measured) Comparable to OECD204 Danio rerio 14d NOEC = 1 mg/L (mean measured)
Short-term toxicity to aquatic invertebrates	OECD202 Daphnia magna EC 50 (48 h): 3.0 mg/L (geometric mean)	Method: EPA OPP 72-2 Daphnia magna EC50 (48h): 2.29 mg/L (mean measured)
Long-term toxicity to aquatic invertebrates	Read across 4-chloro-3-methylphenol	OECD211 Daphnia magna 21d NOEC = 0.32 mg/L (nominal)
Toxicity to aquatic algae and cyanobacteria	OECD 201 Desmodesmus subspicatus ErC 50 (72 h): 24 mg/L, NOErC (72h): 3.2 mg/L (mean measured)	OECD201 Desmodesmus subspicatus ErC50 (72h): 30.62 mg/L (nominal) NOErC (72h): 9.8 mg/L (nominal) Method: ISO Draft comparable with OECD201 Desmodesmus subspicatus ErC50 (72h): 11.12 mg/L (nominal) NOErC (72 h): 3.2 mg/L (nominal)
Toxicity to aquatic microorganisms	OECD 209 Activated sludge EC10 (3h): 29.9 mg/L, EC50 (3h): 109.5 mg/L	ISO 8192 Activated sludge EC25 (30 min): 20.4 mg/L EC50 (30 min): 60.3 mg/L

Acute toxicity of the reaction mass to aquatic organisms was studied for three trophic levels (fish, aquatic invertebrates and algae). For fish an LC50 (96h) of 6.7 mg/L is reported. Daphnia magna turned out to be the most sensitive species with a reported EC50 (48h) of 3.0 mg/L. Testing with green algae resulted in an ErC50 (72h) of 24 mg/L and in a NOEC of 3.2 mg/L.

No long-term toxicity studies on fish and aquatic invertebrates for the reaction mass are available. The substance is a mixture of four different m-cresols which are similar in physico-chemical properties, environmental fate and metabolism.

For one of the components of the reaction mass (4-chloro-m-cresol, CAS No. 59-50-7) aquatic long-term toxicity was investigated for fish and daphnia. These studies are used as read across for the reaction mass. Fish was shown to be more sensitive with a NOEC of 0.15 mg/L than Daphnia magna with a NOEC of 0.32 mg/L.