3-methoxy-N,N-dimethylpropionamide

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 10, 2011 - January 12, 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

There is uncertainty about the listed weights in the sampling table as specified below.

Qualifier:

according to guideline

Guideline:

OECD Guideline 305 B (Bioaccumulation: Semi-static Fish Test)

Version / remarks:

1981

Deviations:

no

GLP compliance:

yes

Radiolabelling:

no

Details on sampling:

See "Any other information on materials and methods incl. tables"

Water samples were obtained for analysis e.g. by siphoning through inert tubing from a central point in the test chamber. Take 7 fish from the test chambers at each sampling time. Rinse the sampled fish quickly with water, blot "dry", kill instantly, using the most appropriate and humane method, and then weigh.

Vehicle:

no

Details on preparation of test solutions, spiked fish food or sediment:

The test solutions were prepared by directly dissolving appropriate amount of test substance in dilution medium through stirring and then facilitating its dispersion by ultrasonication for 20 min.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebra fish
- Source: from a commerial fish supplier of Guangzhou Hongfa Aquatic Animals Culture Company in China
- Length at study initiation: 3.0 +/- 0.5 cm (including the length of the tail)
- Weight at study initiation: 0.5 +/- 0.1 g wet weight
- Weight at termination: not indicated
- Method of breeding: not indicated
- Lipid content at test initiation (mean and range, SD): not indicated
- Health status: Following a 48-hour settling-in period, no fish were dead in the holding time of 7 d. The fish used in tests were free from observable diseases and abnormalities. Fish did not receive any treatment for disease in the two weeks preceding the test, and during the test.
- Description of housing/holding area: In the test, tanks made of glass with a capacity of approximately twenty five liters were employed
- Feeding during test
- Food type: same as during acclimation period
- Amount: Level of approximately 1 to 2% of body weight per day.
- Frequency: daily; siphon uneaten food and faeces daily from the test chambers shortly after feeding (30 minutes to 1 hour). On the days of renewal, feeding is peformed 1-2 hours before changing test solutions.

ACCLIMATION
- Acclimation period: 17 days
- Acclimation conditions (same as test): yes
- Type and amount of food: The fish food (Batch No: E20110805) was supplied by shanghai baoYe Co., Ltd. The ingredients of the fish food are given as follows: Crude Protein >49 .0%, Crude Fat > 5 .0%, Crude Fibre< 3.0%, Crude Ash< 12.0%, Moisture< 10.0%. Level of approximately 1 to 2% of body weight per day
- Feeding frequency: daily, fish were held without food for approximately 24 hours before being placed into the test vessels.
- Health during acclimation (any mortality observed): not specified

Route of exposure:

aqueous

Justification for method:

minimised test method used to support BCF estimates based on Kow

Test type:

semi-static

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Hardness:

140-141 mg CaCO3/L

Test temperature:

23.2-23.8 ºC

pH:

7.24-7.28

Dissolved oxygen:

90-96%

TOC:

1.91 mg/L in dilution water

Salinity:

not applicable

Details on test conditions:

TEST SYSTEM
- Test vessel: all glass
- Material, size, headspace, fill volume: 20 liter
- Aeration: none
- Renewal rate of test solution (frequency): 48 hours
- No. of organisms per vessel: 70
- No. of vessels per concentration (replicates): 2
- No. of vessels per control / vehicle control (replicates): unsure whether controls were present (the text states that controls were included, but no data on controls are available)
- Biomass loading rate: 1.0 g wwt/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Good quality tap water which had been dechlorinated for at least 24 hours was used as holding water.
- Holding medium different from test medium: no

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

STUDY DESIGN/PRELIMINARY STUDY
- Test concentrations: The highest test concentration was selected as 10 mg/L according to the acute 96 h LC50 and NOEC value. The lowest concentration was selected as 1.0 mg/L, which was ten-fold lower than the highest concentration value.

Nominal and measured concentrations:

1 mg/L and 10 mg/L nominal concentrations. No information is available on measured test substance concentrations during the renewal periods; however, based on the measured test substance concentrations on days 0, 3, 7, 10, 14, 21 and 28, it can be observed that the test concentration remained stable thoughout the test (within +/- 20% of nominal).

Reference substance (positive control):

not required

Key result

Conc. / dose:

1 mg/L

Temp.:

ca. 23 °C

pH:

7.3

Type:

BCF

Value:

3.85 L/kg

Basis:

whole body w.w.

Time of plateau:

20 d

Calculation basis:

steady state

Remarks:

was visually determined

Key result

Conc. / dose:

10 mg/L

Temp.:

ca. 23 °C

pH:

7.3

Type:

BCF

Value:

2.86 L/kg

Basis:

whole body w.w.

Time of plateau:

20 d

Calculation basis:

steady state

Remarks:

was visually detrmined

Validity of the test:

The test conditions remained stable; the dissolved oxygen concentration was >= 90% (and thus > 60%) during the test; the test substance concentrations in the test vessels were maintained within ± 20% of the nominal test concentrations; the mortality in control and treated fish is 0% (and thus < 10%) at the end of the test.

Validity criteria fulfilled:

yes

Remarks:

see any other information on results

Conclusions:

The bioconcentration test was performed in accordance with OECD 305B (1981) and in compliance with GLP. Zebrafish were exposed to 1 and 10 mg/L of the test substance under semi-static conditions with 48h renewal. BCF values were measured following 28-day exposure period. Test concentrations in water and fish samples were measured using a validated UPLC-PDA method. A steady state was obtained around day 20 and the related BCF values were 3.85 L/kg at 1 mg/L and 2.86 L/kg at 10 mg/L.

Executive summary:

The bioconcentration test was performed in accordance with OECD 305B (1981) and in compliance with GLP. Zebrafish were exposed to 1 and 10 mg/L of the test substance under semi-static conditions with 48h renewal. BCF values were calculated following 28-day exposure period. Test concentrations in water and fish samples were measured using a validated UPLC-PDA method. Mean recoveries in the water samples was between 96.0%~ 96.2% and RSD was 0.33%~2.54 % for added test substance concentrations of 1 and 10 mg/L. Mean recoveries in the fish samples were between 90.8%-94.4% and RSD was 3.00%-3.28% for added test substance concentrations of 1.00 and 50.0 mg/kg. The LoD was 0.2 mg/L and 1.0 mg/kg in water and fish samples, respectively. No information was available on measured test substance concentrations during the renewal periods; however, based on the measured test substance concentrations on days 0, 3, 7, 10, 14, 21 and 28, it can be observed that the test concentration remained stable thoughout the test.

A steady state was observed around day 20 and the related BCF values were 3.85 L/kg at 1 mg/L and 2.86 L/kg at 10 mg/L. The BCF values are related to total fish wet weight and not to the lipid content of the fish.

Description of key information

The bioconcentration test was performed in accordance with OECD 305B (1981) and in compliance with GLP. Zebrafish were exposed to 1 and 10 mg/L of the test substance under semi-static conditions with 48h renewal. BCF values were calculated following 28-day exposure period. Test concentrations in water and fish samples were measured using a validated UPLC-PDA method. Mean recoveries in the water samples was between 96.0%~ 96.2% and RSD was 0.33%~2.54 % for added test substance concentrations of 1 and 10 mg/L. Mean recoveries in the fish samples were between 90.8%-94.4% and RSD was 3.00%-3.28% for added test substance concentrations of 1.00 and 50.0 mg/kg. The LoD was 0.2 mg/L and 1.0 mg/kg in water and fish samples, respectively. No information was available on measured test substance concentrations during the renewal periods; however, based on the measured test substance concentrations on days 0, 3, 7, 10, 14, 21 and 28, it can be observed that the test concentration remained stable thoughout the test.

A steady state was observed around day 20 and the related BCF values were 3.85 L/kg at 1 mg/L and 2.86 L/kg at 10 mg/L. The BCF values are related to total fish wet weight and not to the lipid content of the fish.

Key value for chemical safety assessment

BCF (aquatic species):

3.85 L/kg ww