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Ecotoxicological information

Long-term toxicity to fish

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Reference
Endpoint:
fish short-term toxicity test on embryo and sac-fry stages
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar toxicological properties because
• they are manufactured from similar or identical precursors under similar conditions
• they share structural similarities with common functional groups: quaternary ammonium and saturated or unsaturated alkyl chains with comparable length (corresponding to scenario 2 of the read-across assessment framework)

The read-across hypothesis is based on structural similarity of target and source substances. Based on available experimental data, including key physicochemical properties and data from acute toxicity, irritation, sensitization (human) and genotoxicity studies, the read-across strategy is supported by a quite similar toxicological profile of all substances.

Therefore, read-across from the existing ecotoxicity, environmental fate and toxicity studies conducted with the source substances is considered as an appropriate adaptation to the standard information requirements of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

A justification for read-across is attached to IUCLID section 13.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See justification for read-across attached to IUCLID section 13.

3. ANALOGUE APPROACH JUSTIFICATION
See justification for read-across attached to IUCLID section 13.

4. DATA MATRIX
See justification for read-across attached to IUCLID section 13.
Reason / purpose:
read-across source
Reason / purpose:
read-across: supporting information
GLP compliance:
no
Test organisms (species):
Pimephales promelas
Water media type:
freshwater
Total exposure duration:
35 d
Nominal and measured concentrations:


All effect concentrations are based on mean measured levels of the active ingredient.
In well water the measured concentrations were equal to the nominal concentrations whereas in river water measured concentrations averaged 45-67% of the nominal concentrations.
Duration:
35 d
Dose descriptor:
NOEC
Effect conc.:
0.115 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Remarks:
in standard water
Basis for effect:
other: hatchability and mean weight of larvae
Remarks on result:
other: extrapolated based on differences in QSAR estimation
Duration:
35 d
Dose descriptor:
NOEC
Effect conc.:
0.027 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Remarks:
in river water
Basis for effect:
other: survival, lenght and weight of larvae
Remarks on result:
other: extrapolated based on differences in QSAR estimation
Conclusions:
NOEC-35d = 0.115 mg/L (river water)
NOEC-35d = 0.027 mg/L (well water)

Description of key information

NOEC = 0.027 mg/L (read-across from DTDMAC)

Key value for chemical safety assessment

EC10, LC10 or NOEC for freshwater fish:
0.027 mg/L

Additional information

No experimental data are available for the target substance Di-C12-18 alkyldimethyl ammonium chloride. However, long-term toxicity studies in fish are available for the closely related source substance DTDMAC. A justification for read-across is attached to IUCLID section 13.

 

To assess the long-term toxicity of DTDMAC embryo larval tests were conducted with Pimephales promelas in filtered well water and natural river water. Exposure was initiated within 48 hours after fertilization and continued through 30 days post hatch in a flow-through system. In well water the most sensitive parameters were mean percent survival, length and weight of larvae. The NOEC was 0.053 mg/l (measured concentration) after 34 days test duration. In river water the NOEC for the most sensitive parameters hatchability and mean weight of larvae was 0.23 mg/l after 33 days test duration. The river water (Town River) had the following characteristics: pH = 6.4 - 6.9, total hardness = 62 mg/l CaCO3, 9.4 mg/l suspended solids, 0.59 mg/l MBAS and triethyleneglycol was used as carrier solvent. The well water had a hardness of 28 -31 mg/l CaCO3, pH = 6.8-7.6 and isopropanol was used as carrier solvent. In well water the measured concentrations were equal to the nominal concentrations whereas in river water measured concentrations averaged 45-67% of the nominal concentrations.

 

From the QSAR data on short-term toxicity it was deduced, that the target substance should be expected to be more toxic than the source substance DTDMAC, and a factor of approx. 2 should be applied to the NOEC obtained in this study. Thus, the NOEC of the target substance Di-C12-18 alkyldimethyl ammonium chloride is considered to be 0.027 mg/L.