2-methylbutyl acrylate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

migrated 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: see 'Remark'

Remarks:

Read-across of data for an analogous chemical.The target chemical and the source chemical are very closely related alkyl acrylate compounds. They differ only by the addition of a methyl group in the butyl portion of the molecule. Both molecules are expected to be metabolized via the same hydrolysis and enzymatic pathways. The data from the source chemical are experimental results from well documented study (comparable to guideline study) which meet basic scientific principles and are considered to be acceptable with restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

Principles of method if other than guideline:

This test was performed in principle as described in OECD Guideline 403.
Ten male and ten female rats (Sprague-Dawley) were exposed by head-nose exposure to butyl acrylate vapour analyzed concentrations of 2.7, 3.6, 4.96, 6.8, 8.1, 12.1 and 16.0 mg/L. The animals were observed over a 14 day period after exposure.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Butyl acrylate

EC Number:

205-480-7

EC Name:

Butyl acrylate

Cas Number:

141-32-2

IUPAC Name:

butyl acrylate

Details on test material:

- Name of test material (as cited in study report): Butyl acrylate
- Physical state: liquid
- Analytical purity: Technically pure

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPRA (SPF 68 Han), MUS RATTUS, Brunnthal
- Weight at study initiation: 185±15 g
- Diet: Herilan MRH, H . EGGERSMANN KG, ad libitum
- Water: Tap water, ad libitum

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose/head only

Remarks:

head-nose exposure

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
A dynamic inhalation system was used in the present study where exposure concentrations of butyl acrylate were generated by pumping liquid butyl acrylate at constant rates into glass vaporization flasks heated to 70°C, the vapours were mixed with fresh air and transmitted to the exposure chamber.


TEST ATMOSPHERE
- Brief description of analytical method used: The butyl acrylate air mixture was measured continuously using a flame ionization detector (FID). Apparatus used was FID total hydrocarbons analyzer (CARLO ERBA).
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

2.7, 3.6, 4.96, 6.8, 8.1, 12.1 and 16.0 mg/L

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology

Statistics:

Statistical analysis were made according to Probit-Analysis, D.J. Finney, 1971.

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC50

Effect level:

10.3 mg/L air (analytical)

Exp. duration:

4 h

Effect levels 2

Sex:

male

Dose descriptor:

LC50

Effect level:

11.2 mg/L air (analytical)

Exp. duration:

4 h

Effect levels 3

Sex:

female

Dose descriptor:

LC50

Effect level:

10 mg/L air (analytical)

Exp. duration:

4 h

Mortality:

No animals died in the 2.7, 3.6 and 4.96 mg/L dose groups, respectively. 1/20, 4/20, 13/20 and 20/20 died in the 6.8, 8.1, 12.1 and 16.0 mg/L dose groups, respectively.

Clinical signs:

other: No clinical symptoms were observed in the 2.7 mg/L dose group. In the 3.6 mg/L dose group, irregular respiration and squatting position were observed, as well as unregular gait. In the 4.96 to 8.1 mg/L dose groups eye and nasal secretion, noisy irregular

Body weight:

There was no adverse effect on the body weight gain in all male animals of the dose groups (6.8 and 2.7 mg/L) and all female animals of the dose groups (8.1, 6.8 and 4.96 mg/L) in comparison to controls. The body weight gain in the male animals of dose groups (12.1 and 3.6 mg/L) and in female animals of dose groups (12.1, 3.6 and 2.7 mg/L) were strongly affected 7 days after the exposure. All the animals in the affected groups recovered by the end of the experimental period except for the male animals of dose groups (12.1 and 3.6 mg/L).

Gross pathology:

Acute dilatation and acute hyperemia of the heart, spotted haemorrhages and acute emphysema in lungs, broaden grey-brown periphery of hepatic lobules were observed in the deceased animals. No pathological lesions were observed in the sacrificed animals.

Any other information on results incl. tables

Concentration (mg/L)		Mortality
Analytical	Nominal	Male	Female
16.0	17.8	10/10	10/10
12.1	12.6	7/10	6/10
8.1	8.4	0/10	4/10
6.8	7.1	1/10	0/10
4.96	5.04	0/10	0/10
3.6	3.9	0/10	0/10
2.7	2.6	0/10	0/10

1 . LC50 (4 h) for male and females rats = 10.3 mg/ L air (1970 ppm)

2 . LC50 (1 h) for male and females rats = 41.2 mg / L air (7860 ppm)*

3 . LC50 (4 h) for male rats = 11.2 mg / L air (2140 ppm)

4 . LC50 (1 h) for male rats = 44.8 mg / L air (8540 ppm)*

5 . LC50 (4 h) for female rats = 10.0 mg / L air (1910 ppm)

6 . LC50 (1 h) for female rats = 45.0 mg / L air (7630 ppm)*

* calculated from 4h LC50 values

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Migrated information Criteria used for interpretation of results: EU

Executive summary:

The results presented in this summary are experimental results for the source chemical n-butyl acrylate. The results are considered to be appropriate for read-across to the target chemical 2-methylbutyl acrylate.