(E)-2-methylpent-2-en-1-oic acid

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: read-across from a guideline study

Justification for type of information:

The information is derived from read across. The read across rationale is presented in the Aquatic toxicity Endpoint summary.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 130 mg/L

Basis for effect:

mobility

Remarks on result:

other: read-across from Methacrylic acid, conversion is not needed because it is a > value

Validity criteria fulfilled:

yes

Remarks:

Annex XI criteria for read across are fulfilled

Conclusions:

The EC50 for Daphnia is > 130 mg/l.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The information is used for read across to Fragarone

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1300 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

At each sampling period 5 ml aliquots of test water were collected from each of the four replicates of each test solution. Two replicates at each time
point were composited.

Vehicle:

no

Details on test solutions:

A primary stock standard of MAA was prepared and stored at room temperature. Subsequent dilutions were prepared in Milipore water for use as
spiking solutions and test dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

ABC Laboratories in house culture. Age at study initiation: first instar (<=24 hours old). Organisms were held in temperature controlled area at 20°C. Lighting was 50-70 footcandles on a 16 hr photoperiod, with 30 minute dawn and dusk transition periods, Organisms were not fed during the 48 hr
treatment period.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

172-178 mg/L

Test temperature:

20°C

pH:

7.0-7.9

Dissolved oxygen:

7.7-8.2 mg/L

Nominal and measured concentrations:

Nominal= 7.2, 14, 30, 60 and 120 mg/L.
Mean measured (sampling at 0 and 48 hrs) = 6.7, 13, 32, 62 and 130 mg/L.

Details on test conditions:

Method: flow-through bioassay as described in American Public Health Association and Standard Methods for the Examination of Water and 
Wastewater.

A half liter proportional diluter system was used for intermittent introduction of dilution water and MAA into the test chambers. The test system contained six sets of four replicate one liter test chambers designated as control, and level 1 through level 5. The proportional diluter was calibrated preior to use in the test.

Dilution water was a blend of reverse osmosis water and ABC laboratory well water.

10 organisms were assigned to each of the four replicate test chambers (40 Daphnids per concentration).
Water quality measurements were recorded at 0 and 48 hours.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 130 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: The 48 hr dose response slope could not be determined because of lack of an effect level.

Details on results:

Overall, the measured concentrations represent 101-7.4% of nominal concentrations. Quality control samples analyzed with each sample day over a range of 6.00 to 150 mg/L with recoveries averaging 94+/-19%. Low recovery for the 0 hour sampling was obtained. Duplicate low spikes at teh 48 hour sampling were analyzed to verify the recovery of MAA at the 6.00 mg/l concentration.

Measurement at 0 and 48 hrs of the MAA diluter stock solution averaged 12,000 mg/L which represented 100% of the nominal concentration (12,000 mg/L).

Validity criteria fulfilled:

yes

Conclusions:

In a valid guideline study, the 48 hour EC50 for Daphnia magna was >130 mg/L MAA.

Executive summary:

In a valid guideline study, the 48 hour EC50 for Daphnia magna was >130 mg/L MAA.

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

The short-term toxicity to aquatic invertebrates is assessed based on read-across from the close structural analogue Methacrylic acid (CAS# 79 -41 -4). The data of Methacrylic acid are summarised below.

For Methacrylic acid, the short-term toxicity to daphnids was examined in a study according to EAP OTS 797-1300 (equivalent to OECD TG 202), and in compliance with GLP criteria (MPA, 1990). Groups of 40 Daphnia magna (4 replicates of 10 animals) were exposed to nominal test substance concentrations 0 (control), 7.2, 14, 30, 60 and 120 mg/L for 48 hours under flow-through conditions. Test substance analysis was performed and mean measured concentrations determined at 6.7, 13, 32, 62 and 130 mg/L. Daphnia mobility was recorded. The 48-h EC50 was determined at >130 mg/L based on mean measured concentrations.