Hexyl methacrylate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

Adoped July 17th, 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

The test concentration were checked analytically by HPLC at test start and every 24 hours.

Vehicle:

no

Details on test solutions:

The pure test substance was weight in directly to prepare stock solutions which were continously applied by dosage pumps.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
The criteria of the test guideline (OECD 203) were considered. Only healthy fish without diseases and abnormalities were used in the study.

- Common name: Danio rerio (Teleostei, Cyprinidae)
- Strain: Danio rerio (Teleostei, Cyprinidae) (HAMILTON-BUCHANAN)
- Source: West Aquarium GmbH, D-37431 Bad Lauterberg, Germany

- Age at study initiation (mean and range, SD): no data

- Length at study initiation (length definition, mean, range and SD): 2.6 cm; 2.2 -2.9 cm; SD 0.2 cm
- Weight at study initiation (mean and range, SD): mean weight: 0.20 ± 0. 05 g
- Method of breeding: Laboratory bred
- Feeding during test: fish were not fed during the test (beginning 24 h prior to initiation)
- Food type: TetraMin® Hauptfutter

- Amount: no data
- Frequency: no data

ACCLIMATION
- Acclimation period: no data
- Acclimation conditions (same as test or not): fish were acclimatized in water of the same quality as used in the test
- Health during acclimation (any mortality observed): no data

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

not specified

Test temperature:

varied between 21.8 and 22.1 °C

pH:

varied between 7.5 and 8.2

Dissolved oxygen:

in all test vessels between 63% and 94%

Salinity:

not specified

Conductivity:

not specified

Nominal and measured concentrations:

0 (control), 9.4, 18.8, 37.5, 75.0 and 150 mg/L (nominal concentrations)
0 (control), 2.9, 5.6, 9.5, 22.3, and 46.6 mg/ (mean measured test concentrations)
The measured values deviated by more than 20 % from nominal values at all dose levels.

Details on test conditions:

The pure test substance was weight in directly to prepare stock solutions which were continously applied by dosage pumps.


Test priciples and procedure:

10 fish were used for each test concentration including controls.
Only fish in good health and free from any apparent malformation were used.


15-l glass aquaria were used as test vessels and filled with 10 l of test solution. The test animals were added to the previously prepared test solution; controls were kept in dilution water (blank).

The aquaria were slightly aerated via a glass capillary throughout the test.


The fish were exposed to various concentrations of the test substance for a period of 96 hours under flow through conditions. . Visible abnormalities and mortalities were recorded after 24 h, 48 h, 72 h, and 96 h. Dead animals were eliminated from the vessels as soon as they were discovered.

The test temperature was 21.8° C to 22.1 ° C. The pH of the dilution water was 7.5 to 8.2. The oxygen saturation in all test vessels was between 63 % and 94 %.

The pH, temperature and the oxygen concentrations of the control and of all the test concentrations were measured daily.

TEST SYSTEM
- Test vessel: 15-l glass aquaria
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass; filled with 10 L of test solution
- Aeration: aeraeted via glass capillary
- Type of flow-through (e.g. peristaltic or proportional diluter): dosage pumps (not further specified)
- Renewal rate of test solution (frequency/flow rate): The flow rate was 2.5 l*h-1. The stock solutions were prepared every day; pure test substance was weight in directly for preparation.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): not specified
- No. of vessels per control (replicates): not specified
- No. of vessels per vehicle control (replicates): not specified
- Biomass loading rate: 0.2 g*L-1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Purified drinking water; purification included filtration with charcoal, aeration and passage through a lime stone column; water was aerated to oxygen saturation prior to preparation of the test solutions.
- Total organic carbon: no data
- Particulate matter: no data
- Metals: no data
- Pesticides: no data
- Chlorine: no data
- Alkalinity: no data
- Ca/mg ratio: no data
- Culture medium different from test medium:no
- Intervals of water quality measurement: daily

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: 14/10
- Light intensity: not specified

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
-Visible abnormalities and mortalities were recorded after 24 h, 48 h, 72 h, and 96 h.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline:
- Range finding study: not specified
- Test concentrations: 0 (control), 9.4, 18.8, 37.5, 75.0 and 150 mg/L (nominal concentrations) ; 0 (control), 2.9, 5.6, 9.5, 22.3, and 46.6 mg/ (mean measured test concentrations)
- Results used to determine the conditions for the definitive study: mean measured test concentrations

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

7.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: confidence limits 6.2 -8.9 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

2.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

5.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC10

Effect conc.:

5.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Details on results:

The measured values deviated by more than 20 % from nominal values at all dose levels. Thus, the mean measured concentrations were taken as basis for the calculation of the lethal effect concentrations.

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

NOEC and LOEC were determined dirctly in the test.
LC10 and LC50 values as well as the confidence limits of the LC50 were derived from a concentration effect curve fitted to the data by non-linear regression (probit analysis)

Validity criteria fulfilled:

yes

Remarks:

-Criteria of OECD 203: Mortality of controls <1

Conclusions:

In a valid guideline study (OECD 203, flow through conditions), the 96 hr LC50 for Danio rerio (Teleostei, Cyprinidae) is 7.4 mg/L .

Executive summary:

In a 96-h acute toxicity study, Danio rerio (Teleostei, Cyprinidae) were exposed to n-hexyl methacrylate

at 0 (control), 9.4, 18.8, 37.5, 70.0, 140 mg/L nominal and 0 (control), 2.9, 5.6, 9.5, 22.3, 46.6 mg/L measured concentrations under flow through conditions. The 96 -h LC₅₀was 7.4 (6.2 - 8.9 95 % confidence limits) mg a.i./L. The LC₁₀and NOEC values, based on mortality effects, were 5.2 mg/L and 2.9 mg a.i./L, respectively. The effect concentrations refer to the mean measured concentrations, because the measured concentrations deviated by more than 20 % from the nominal values. Based on the results of this study, n-hexyl methacrylate would be classified as non toxic to Danio rerio (fish) in accordance with the classification system of the EU.

 

This toxicity study is classified as acceptable and satisfies the guideline requirement for OECD 203, Danio rerio (Zebra fish) toxicity study.

 

Results Synopsis

 

Test organism size/age: mean weight: 0.20 ± 0.05 g, length: 2.2 -2.9 cm

Test Type: flow through, continously application by dosage pumps, stock solutions prepared and changed completely every 24 hours

 

LC₅₀: 7.4 mg a.i./L                         95% C.I.: 6.2 to 8.9 mg a.i./L

NOEC: 2.9 mg a.i./L                      

LC₁₀:  5.2 mg a.i./L}                      

Endpoint(s) Effected: mortality

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Description of key information

In a valid guideline study (OECD 203, flow through conditions), the 96 hr LC50 for Danio rerio (Teleostei, Cyprinidae) is 7.4 mg/L (Evonik Oil Additives GmbH, 2001).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

7.4 mg/L

Additional information

There is one reliable key study available for n-hexyl methacrylate. A valid guideline study (OECD 203, flow through conditions), the 96 hr LC50 for Danio rerio (Teleostei, Cyprinidae) is 7.4 mg/L (Evonik Oil Additives GmbH, 2001).

There is no data on marine fish, but studies with the common metabolite, methacrylic acid, indicate that marine species are not expected to be more sensitive to methacrylates than freshwater species (Sverdrup, 2001).