Propylidynetrimethyl trimethacrylate

Long-term toxicity to fish

Description of key information

The NOEC of TMPTMA on time to hatch and hatching success in fathead minnows is =1.431 mg/L. The NOEC for mortality, body weight and fry length is 0.138 mg/L. 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Effect concentration:

0.138 mg/L

Additional information

The effects of prolonged exposure to Propylidynetrimethyl Trimethacrylate (EC/CAS N. 221 -950 -4/3290 -92 -4) on the early life stages of the fathead minnow (Pimephales promelas) were assessed over embryo development, hatching and for 28 days post-hatch, in accordance with OECD Guideline 210 (1992).

The definitive test was conducted under continuous flow conditions, with embryos (<24 h old) exposed to the following nominal concentrations: 0.02, 0.064, 0.2, 0.64 and 2 mg/L of TMPTMA. Both solvent and non-solvent controls were included in the test. Chemical analysis of test samples taken during the exposure phase indicated that measured concentrations of TMPTMA were not maintained at 80-120% of nominal, at all test concentrations over the test period. The geometric mean measured concentrations of TMPTMA were calculated as 0.017, 0.052, 0.138, 0.442 and 1.431 mg/L for the respective nominal concentrations of 0.02, 0.064, 0.2, 0.64 and 2 mg/L.

Statistical analysis indicated a significantly higher mortality in the 0.442 and 1.431 mg/L treated groups than in the solvent control. There was no significant difference in mortality between the 0.017, 0.052 and 0.138 mg/L treated groups and the solvent control. The LC_5,LC_10,LC₂₀ and LC₅₀ values were estimated to be 0.051, 0.074, 0.117 and 0.276 mg/L, respectively. The NOEC for mortality is concluded to be 0.138 mg/L; the corresponding LOEC is concluded to be 0.442 mg/L.

Fry length and body weight were measured at the end of the test. Statistical analysis indicated no significant differences in length and body weight between the 0.017, 0.052 and 0.138mg/L treatment groups and the solvent control group. There was however a significant difference between the 0.442 mg/L treatment group and the solvent control. The NOEC for effect on length and body weight loss is therefore concluded to be 0.138 mg/L; the corresponding LOEC for effect on length and body weight loss is concluded to be 0.442 mg/L.

 

Based on the above results, mortality, fry length and body weight appear to be the most sensitive parameters in the early life stage test of the fathead minnow, with the NOEC for TMPTMA being 0.138 mg/L. As no significant mortalities were at the lower concentrations than 0.138 mg/L (geometric mean measured concentrations), LC₁₀ was appraised from a too low number of data to be reliable. Therefore, the NOEC for mortality (0.138 mg/L) was used for Chemical Safety Assessment (CSA).