Bis(4-chlorophenyl) sulphone

Long-term toxicity to fish

Description of key information

The NOEC for freshwater fish is assigned on the basis of a chronic exposure to a non-toxic concentration.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.05 mg/L

Additional information

In the course of the Japanese Chemical Substances Control Act from 1974 studies a bioaccumulation test in fish was conducted (NITE 2002,Table 17, p28). According to the applied protocols the concentration for sub-lethal or chronic effects was assumed to be at about 1% of the acute effects. This is in line with ECETOC TR 13 (1984). In order to derive this value, fish were exposed up to about 50 times the water solubility of DCDPS (Table 41, p105) and an acute LC₅₀> 50 mg/L was derived, placing the assumed chronic effect level in the order of 0.5 mg/L (i.e. 1% of 50 mg/L). Therefore the higher exposure concentration in the bioaccumulation study concentration was intentionally chosen by AF of 10 an 100 lower in order to prevent chronic toxicity (test concentrations of 0.05 and 0.005 mg/L were used).

In conclusion the bioconcentration study (NITE 2002) delivers a long-term 35-day observation in fish quite far away from the assumed chronic effect level, and can therefore be considered a limit testing for DCDPS performed at 0.01% of the LC₅₀ (i.e. an EC₀). The test concentrations chosen did not permit the determination of threshold level for the lethal and other observable effects because of the absence of a LOEC. Thus the NOEC for chronic exposure is assigned to this EC₀ value (0.05 mg/L), which constitutes a large safety margin to the assumed chronic effect levels.