Didecyldimethylammonium chloride

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

No analytical dose verification

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Test organisms (species):

Daphnia magna

Test type:

static

Limit test:

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 0.057 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: "c"(calculated)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 0.029 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

48hr-EC50 = 0.057 mg/l, with 95% confidence limit 0.046-0.071 mg/L. The highest dose at which 100% immobilisation was observed was 0.32 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 48 h EC50 was found to be 0.057 mg test substance/L (i.e. 0.029 mg a.i./L), with 95% confidence limits of 0.046 - 0.071 mg/L. The highest dose at which 100% immobilisation was observed was 0.32 mg/L.

Executive summary:

A short-term toxicity study with aquatic invertebrates (Daphnia magna) was performed according to OECD Guideline 202 and EU Method C.2, in compliance with GLP. Twenty daphnids per concentration were exposed for 48 h to 0.0032, 0.0056, 0.010, 0.018, 0.032, 0.056, 0.20 or 0.32 mg/L of the test substance (containing 50% a.i.). The test was carried out under static conditions. no analytical dose verification was conducted. The results were therefore expressed as nominal concentrations. Under the study conditions, the 48 h EC50 was found to be 0.057 mg test substance/L (i.e. 0.029 mg a.i./L), with 95% confidence limits of 0.046 - 0.071 mg/L. The highest dose at which 100% immobilisation was observed was 0.32 mg/L (Douglas and Handley, 1988).

Description of key information

-         Key value from Registrant: 48 h EC50 = 0.029 mg a.i./L

-         Key value from DDAC biocides assessment report for Product Type 8 (June 2015): 48 h EC50 = 0.062 mg a.i./L

In the present report, the 48 h EC50 of 0.062 mg a.i./L was selected as key value, in line with the methodology followed in the DDAC biocides assessment report for Product Type 8.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.062 mg/L

Additional information

A short-term toxicity study with aquatic invertebrates (Daphnia magna) was performed according to OECD Guideline 202 and EU Method C.2, in compliance with GLP. Twenty daphnids per concentration were exposed for 48 h to 0.0032, 0.0056, 0.010, 0.018, 0.032, 0.056, 0.20 or 0.32 mg/L of the test substance (containing 50% a.i.). The test was carried out under static conditions. no analytical dose verification was conducted. The results were therefore expressed as nominal concentrations. Under the study conditions, the 48 h EC50 was found to be 0.057 mg test substance/L (i.e. 0.029 mg a.i./L), with 95% confidence limits of 0.046 - 0.071 mg/L. The highest dose at which 100% immobilisation was observed was 0.32 mg/L (Douglas and Handley, 1988).

The DDAC biocides assessment report for Product Type 8 conducted under Directive 98/8/EC (evaluating Competent Authority: Italy, June 2015, attached in Section 13 of the IUCLID dataset), reported an additional study on DDAC, apart from the above EQC study. This study, seen as more reliable as it included an analytical dose verification, resulted in a 48 h EC50 = 0.062 mg a.i./L. The RMS considered the value from this study as the endpoint for the product authorisation.