methyl acrylate; methyl propenoate

Toxicity to soil microorganisms

Administrative data

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 Feb - 18 Mar 2010 (Experimental Starting and Completion Date)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD guideline study conducted in compliance with GLP regulations

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 217 (Soil Microorganisms: Carbon Transformation Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methyl acrylate

EC Number:

202-500-6

EC Name:

Methyl acrylate

Cas Number:

96-33-3

Molecular formula:

C4H6O2

IUPAC Name:

methyl prop-2-enoate

Details on test material:

- Name of test material (as cited in study report): Acrylic acid, methyl ester
- Analytical purity: > 99.5 %
- Lot/batch No.: 010854eda0 MA-rein aus B16-03 Prueftank 841603
- Expiration date of the lot/batch: Dec 2010

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

The glucose-induced respiration rate in each treated and control replicate was determined at each sampling time. 3 subsamples per 100 g dry matter soil to be analyzed were taken for 3 times during the exposure. The soil samples were mixed with 200 mg glucose to elicit an immediate maximum respiratory response.
The glucose was mixed with 1 g clean quartz sand and homogeneously mixed with the soil. The glucose/soil samples were incubated in a suitable apparatus for measurement of respiration rates either continuously, every hour at 20 +/- 2 °C.
The carbon dioxide released or the oxygen consumed was measured for 12 consecutive hours and measurements were started within 1 to 2 hours after glucose supplement. The total quantities of carbon dioxide released during the 12 hours were measured and mean respiration rates were determined.

Test substrate

Vehicle:

yes

Details on preparation and application of test substrate:

AMENDMENT OF SOIL
- Type of organic substrate: glucose



APPLICATION OF TEST SUBSTANCE TO SOIL
- Method: by stock solution
About 2.5 g/L of test substance was weighed to a volumetric flask. After addition of demineralized water the mixture was stirred at room temperature until the test substance was completely dissolved.

Test organisms

Test organisms (inoculum):

soil

Study design

Total exposure duration:

28 d

Test conditions

Test temperature:

20 +/- 2 °C

Moisture:

45 % +/- 5 %

Details on test conditions:

TEST SYSTEM
- Testing facility: BASF SE
- Test container (type, material, size): 2 L glass containers with sufficient headspace and perforated lid to avoid development of anaerobic conditions
- No. of replicates per concentration:
- No. of replicates per control:


SOIL INCUBATION
- Method: The soil was divided into six portions of equal weight. Five of the samples were mixed with the carrier containing the test substance in test concentrations, and the sixth sample was mixed with the carrier without the test substance (blank control). Incubation of soils was performed as bulk samples of each treated and untreated soil in 2 L glass containers with sufficient headspace and perforated lid to avoid development of anaerobic conditions for 28 days at 20 +/- 2 °C in the dark. The soil was thoroughly mixed before sub sampling at day 0, 7, and 28.
The moisture content of soil was maintained during the exposure at 45 % +/- 5 % of the maximum water holding capacity by weighing. Demineralized water was added as needed.


SOURCE AND PROPERTIES OF SUBSTRATE
- Geographical reference of sampling site: The soil was delivered from Landwirtschaftliche Untersuchungs- und Forschungsanstalt Speyer, D-67646 Speyer on 13 January 2010
- History of site:
- Treatments with pesticides or fertilizers: The soil was not treated with crop protection products for one year. No fertiliser application was taken the last three months before sampling the soil.
- Soil texture
- % sand: 62.5 +/- 4.7
- % silt: 28.7 +/- 4.5
- % clay: 8.9 +/- 1.5
- Soil taxonomic classification: Type 2.3 Lufa soil, well defined
Soil type: Silty sand (uS) according to German DIN and a sandy loam according to USDA, respectively.
- pH (in water): 6.7 +/- 0.3
- Maximum water holding capacity (in % dry weigth): 35.6 +/- 3.0 (g/100 g)
- Cation exchange capacity (meq/100 g): 10.0 +/- 2.0
- Initial microbial biomass as % of total organic C:


DETAILS OF PREINCUBATION OF SOIL:
2 days before use in the test, the soil was pre incubated at 20 +/- 2 °C and 45 % +/- 5 % of the maximum water holding capacity moisture content of the soil.


EFFECT PARAMETERS MEASURED: respiration rate



RANGE-FINDING STUDY
- Results used to determine the conditions for the definitive study: EC50 > 1000 mg/kg dry mass soil

Nominal and measured concentrations:

Nominal: 0, 63, 125, 250, 500, and 1000 mg/kg dry mass soil

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

respiration rate