3-methoxy-N,N-dimethylpropionamide

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

adult fish: sub(lethal) effects

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 September 2011 - 10 February 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)

Version / remarks:

1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: SEPA: HJ/T 153-2004

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples were taken from all test solutions at the beginning (0 d), immediately prior to the first renewal of the test solution (3 d) and at the termination of the test (14 d). The water samples collected were diluted 10-fold with methanol/water (v:v = 20:80) and then filtrated by a 0.22 µm filter. The filtrates were anlaysed by UPLC/PDA.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: the test solution of Equamide M100 was prepared by directy adding the appropriate amount, for each concentration to be tested, into test water. Ultrasonication for 30 minutes was used to facilitate the dissolving of the test substance.
- Control: dilution medium without test substance

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: the test organisms were obtained from a commercial fish supplier of Guangzhou Hongfa Aquatic Animals Culture Company in China.
- Age at study initiation: juveniles (feeding fry were held for 31 days before being used)
- Length at study initiation: 2.06 cm ± 3.6%
- Weight at study initiation: 0.199 g ± 5.7%
- Feeding during test: daily (the quantity of food being kept constant 2% dry weight related to the initial fish weight)

ACCLIMATION
- Acclimation period: 31 days
- Acclimation conditions: in holding tanks supplied with a continuous flow of aerated water.
- Feeding during acclimation: daily with fish food (>49.0% crude protein, >5.0% crude fat, <3.0% crude fibre, <12.0% crude ash, <10.0% moisture), food was withheld from the stock population for 24 h prior to the start of the test.
- Health during acclimation: after the 48h settling-in period, no mortality was observed in the following 7 days.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

14 d

Hardness:

122.2 mg CaCO3/L

Test temperature:

22-23 °C throughout the exposure period

pH:

7.2-7.3 throughout the exposure period

Dissolved oxygen:

89-99% of the air saturation at the test temperature

Nominal and measured concentrations:

Nominal concentrations: 80, 100 and 120 mg/L
Measured concentrations: 82.2, 94.0 and 125 mg/L on day 0; 81.6, 89.0 and 125 mg/L (aged solutions) and 83.1, 95 and 121 mg/L (fresh solutions) on day 3; 78.2, 92.6 and 127 mg/L on day 14.

Details on test conditions:

TEST SYSTEM
- Test vessel: tanks made of chemically inert material, with a sealable inert lid, volume: approx. 5L
- Aeration: no
- Renewal rate of test solution: every 72 hours
- No. of organisms per vessel: 10
- No. of vessels per concentration: 1
- No. of vessels per control: 1
- Biomass loading rate: 0.5-0.8 g fish/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water, dechlorinated for at least 24 hours.
- Culture medium different from test medium: not indicated
- Intervals of water quality measurement: measurements of pH, dissolved oxygen and temperature were carried out twice a week.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours, daily
- Light intensity: 1000-1500 lux

EFFECT PARAMETERS MEASURED: mortality after 14 days
- In addition, observations were made for effects on the appearance, size (length and body weight) and behaviour of the fish that distinguished them from the control group.

RANGE-FINDING STUDY
- No range-finding study was consducted, the results of an acute fish toxicity test were used to determine the test concentrations.

Reference substance (positive control):

no

Key result

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

behaviour

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

length

Remarks:

(change in length)

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

(pseudospecific growth rate)

Details on results:

- No mortality was observed.
- No abnormal behaviour was observed.
- At the end of the test, the mean weight and length of fish in the controls was increased. However, no statistically significant difference for specific growth rates and the length changing rates was found in any of the tested concentrations.

Reported statistics and error estimates:

Based on analysis of variance (ANOVA, STATA 10.0), the pseudo specific growth rates and the length changing rates for each concentration were compared with the control values using a Dunnett's test (p>0.05).

Validity criteria fulfilled:

yes

Remarks:

There was no mortality in the controls and dissolved oxygen concentrations were >60% (e.g., 89-99%).

Conclusions:

Under the test conditions, the NOEC for Equamide M100 was 120 mg/L, for mortality, behaviour, body length and body weight.

Executive summary:

A long-term toxicity test, according to OECD 204, was performed to assess the effects of Equamide M100 on fish (Brachydanio rerio). The test was conducted under semi-static conditions with renewal of test solutions every 72 hours for a duration of 14 days using 10 fish per test concentration and control. Based on the results of an acute toxicity test to fish, nominal concentrations of 80, 100 and 120 mg/L were used. Test concentrations were analysed and results showed that the test concentrations were 80 -120% of nominal concentrations over the 72 -hour renewal periods (98 -106% of nominal throughout the test period). Mortality, behaviour, bodylength and bodyweight were examined. No fish died during the exposure period and no behaviour abnormalities were observed. Mean length and mean body weight did not differ significantly between the fish exposed to the test item and those of the control. Therefore, the overall NOEC for Equamide M100, based on nominal concentrations, was 120 mg/L. All acceptability criteria were met and the study was considered to be valid.

Description of key information

A long-term toxicity test, according to OECD 204, was performed to assess the effects of Equamide M100 on fish (Brachydanio rerio). The test was conducted under semi-static conditions with renewal of test solutions every 72 hours for a duration of 14 days using 10 fish per test concentration and control. Based on the results of an acute toxicity test to fish, nominal concentrations of 80, 100 and 120 mg/L were used. Test concentrations were analysed and results showed that the test concentrations were 80 -120% of nominal concentrations over the 72 -hour renewal periods (98 -106% of nominal throughout the test period). Mortality, behaviour, bodylength and bodyweight were examined. No fish died during the exposure period and no behaviour abnormalities were observed. Mean length and mean body weight did not differ significantly between the fish exposed to the test item and those of the control. Therefore, the overall NOEC for Equamide M100, based on nominal concentrations, was 120 mg/L. All acceptability criteria were met and the study was considered to be valid.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

120 mg/L