Didecyldimethylammonium chloride

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 Jan, 2004 - 4 Feb, 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

study under GLP and latest protocols

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples were taken on the first day of the study on preparation and just before changing (same solution). Further samples were taken weekly
thereafter following the same procedure.

Details on test solutions:

Initial concentrations of test substance: 0, 0.005, 0.0125, 0.032, 0.08 and 0.2 mg a.i./L (nominal)
Actual concentrations of test substance: 0, 0.0031, 0.0078, 0.020, 0.047 and 0.124 mg a.i./L (measured)

Test organisms (species):

Daphnia magna

Details on test organisms:

-Strain / Clone: Daphnia magna clone 4 stock
-Source: AquaSense, Amsterdam, The Netherlands
-Age: less than 24 hours
-Breeding method: according to standard operation procedure
-Kind of food: Chlorella vulgaris
-Amount of food: 0.1 to 0.2 mg of carbon per daphnid per day
-Feeding frequency: once a day
-Pretreatment: no pretreatment
-Feeding of animals during test: Yes

Test type:

semi-static

Hardness:

Ca / Mg approximately 4:1
Na / K ratio 10:1

Test temperature:

20

pH:

7-8

Dissolved oxygen:

saturated

Salinity:

No information

Nominal and measured concentrations:

Initial concentrations of test substance: 0, 0.005, 0.0125, 0.032, 0.08 and 0.2 mg a.i./L (nominal)
Actual concentrations of test substance; 0, 0.0031, 0.0078, 0.020, 0.047 and 0.124 mg a.i./L (measured)

Details on test conditions:

Test type: Semi-static
Renewal of test solution: every second day and over the weekend after three days
Volume of test vessels: 50 mL glass beakers
Volume/animal: 50 ml
Number of animals/vessel: 1
Number of vessels/ concentration: 10
Test performed in closed vessels due to significant volatility of TS: No

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

ca. 0.021 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

ca. 0.047 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

ca. 0.031 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Details on results:

Mean numbers of living Number of parent
offspring per parent animal alive. animals alive.
measured Conc (mg a.i/l)
Control: 150.5 (CV 7.7%) 8
0.0031: 147.5 (CV 8.1%) 8
0.0078: 140.3 (CV 12.6%) 7
0.020: 169.8 (CV 18.4%) 10
0.047: - 0
0.124 - 0
-Mortality based on measured concentrations: NOEC = 0.053 mg/l (0.021 mg a.i./l); LOEC = 0.118 mg/l (0.047 mg a.i./l)
-Reproduction based on measured concentrations: NOEC = 0.053 mg/l (0.021 mg a.i./l); LOEC = 0.118 mg/l (0.047 mg a.i./l)

Reported statistics and error estimates:

The data was tested for normality using Chi-square test. For homogeneity of variance (p<0.05) Hartley’s and Bartlett’s tests were used.
Analysis of variance was performed on the number of living neonates per parent using the Bonferroni t-test and verified with a second
multiple comparison method, the Dunnett’s test. Multi-comparison tests of group weights and length of parent animals were employed.

Mean numbers of living offspring per parent animal alive and
number of parent animals alive:

Conc       No.            No. 
(mg a.i/l) offspring      parents
__________________________________
Control: 150.5 (CV 7.7%)    8 
0.0031:  147.5 (CV 8.1%)    8
0.0078:  140.3 (CV 12.6%)   7
0.020:   169.8 (CV 18.4%)  10
0.047:   -                  0
0.124    -                  0

CV = coefficient of variation for control fecundity (based
on total number of living offspring per parent animal alive
at the end of the test)

Mortality based on measured concentrations:
NOEC = 0.021 mg a.i./l
LOEC = 0.047 mg a.i./l
EC50 = 0.031 mg a.i./l
Reproduction based on measured concentrations:
NOEC = 0.021 mg a.i./l
LOEC = 0.047 mg a.i./l
EC50 = 0.031 mg a.i./l

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, results (based on mortality as well as reproduction, expressed as measured concentrations of active ingredient) were as follows: NOEC = 0.021 mg/L, LOEC = 0.047 mg/L, EC50 = 0.031 mg/L.

Executive summary:

A long-term toxicity study with aquatic invertebrates (Daphnia magna) was carried out according to OECD Guideline 211, in compliance with GLP. The following nominal concentrations were used: 0, 0.005, 0.0125, 0.032, 0.08 and 0.2 mg /L, corresponding to mean measured values of 0, 0.0031, 0.0078, 0.020, 0.047 and 0.124 mg/L. The test conditions were semi-static, with renewal every second day and over the weekend after three days. Animals were checked daily for immobilisation of parent daphnids by gently shaking the test vessel. From the day of the first brood, observations (aborted, living and dead progeny) were also made at each concentration. The day of brood release and the number of living and dead neonates per brood or abortions were noted. Any other abnormal observations were also recorded. Under the study conditions, results (based on mortality as well as reproduction, expressed as measured concentrations of active ingredient) were as follows: NOEC = 0.021 mg/L, LOEC = 0.047 mg/L, EC50 = 0.031 mg/L (Thomas, 2004).

Description of key information

-         Key value from Registrant: 21 d NOEC = 0.021 mg a.i./L

-         Key value from DDAC biocides assessment report for Product Type 8 (June 2015): 21 d NOEC = 0.014 mg a.i./L

In the present report, the 21 d NOEC of 0.014 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:

0.014 mg/L

Additional information

A long-term toxicity study with aquatic invertebrates (Daphnia magna) was carried out according to OECD Guideline 211, in compliance with GLP. The following nominal concentrations were used: 0, 0.005, 0.0125, 0.032, 0.08 and 0.2 mg /L, corresponding to mean measured values of 0, 0.0031, 0.0078, 0.020, 0.047 and 0.124 mg/L. The test conditions were semi-static, with renewal every second day and over the weekend after three days. Animals were checked daily for immobilisation of parent daphnids by gently shaking the test vessel. From the day of the first brood, observations (aborted, living and dead progeny) were also made at each concentration. The day of brood release and the number of living and dead neonates per brood or abortions were noted. Any other abnormal observations were also recorded. Under the study conditions, results (based on mortality as well as reproduction, expressed as measured concentrations of active ingredient) were as follows: NOEC = 0.021 mg/L, LOEC = 0.047 mg/L, EC50 = 0.031 mg/L (Thomas, 2004).

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 studies. This study resulted in a 21 d NOEC = 0.010 mg a.i./L. The RMS considered both studies as equally valid and therefore used a geomean value of 0.014 mg a.i./L as the endpoint for the product authorisation.