2-dimethylaminoethyl methacrylate

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference 1

Reference Type:

publication

Title:

The subacute inhalation toxicity of 109 industrial chemicals

Author:

Gage JC

Year:

1970

Bibliographic source:

Brit. J. Industr. Med., 27, 1-18

Reference 2

Reference Type:

publication

Title:

Gage J.C., Brit. J. Industr. Med., 27, 1-18, 1970

Author:

Gage JC

Year:

2003

Bibliographic source:

cited in: OECD SIDS, 2-Dimethylaminoethylmethacrylate, CAS No: 2867-47-2, 07/2003

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Short-term vapor inhalation toxicity was studied in rats with a constant flow pump for 3 wks, 5 d/w, 6 h/d.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-dimethylaminoethyl methacrylate

EC Number:

220-688-8

EC Name:

2-dimethylaminoethyl methacrylate

Cas Number:

2867-47-2

Molecular formula:

C8H15NO2

IUPAC Name:

2-(dimethylamino)ethyl methacrylate

Details on test material:

Purity not specified, but commercial grade assumed.

Specific details on test material used for the study:

TEST MATERIAL:
- Name of test material: 2-Dimethylaminoethyl methacrylate

Test animals

Species:

rat

Strain:

other: Alderly Park SPF

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 700 g
- Diet: ad libitum except during exposures
- Water: ad libitum except during exposures

Administration / exposure

Route of administration:

other: inhalation: vapour at 100 ppm, possibly mist at 250 ppm

Type of inhalation exposure:

whole body

Vehicle:

other: air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Rats were exposed in a chamber described elsewhere (Gage, 1959); usually the inner Perspex chamber of that design was replaced by a glass cylinder, 30 cm diameter and 25 cm high.
- Method of conditioning air: The air used for the atmospheres was filtered, dried to a relative humidity of less than 10%, and supplied at a line pressure of 1 atm (1.013x10E+5 NmE-2).
- Method of atmosphere generation: A vapour concentration by injecting a liquid at a known rate into a metered stream of air by means of a controlled fluid-feed atomizer (Gage, 1953).

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

3 weeks

Frequency of treatment:

6 hrs/day, 5 days/week

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

100 ppm (nominal)

Doses / concentrations 2

Dose / conc.:

250 ppm (nominal)

No. of animals per sex per dose:

4

Control animals:

other: At intervals of about two months, batches of control rats were maintained in a chamber for the exposure period, in order to check the characteristics of the colony.

Details on study design:

- Design of the experiments: Alderley Park specific-pathogen-free rats with an average weight of 700 g were used in nlost of these experirnents. They were maintained in the exposure chamber for periods of up to 6 hours, and between repeated daily exposures they were returned to their cages where food and water were freely available. In the initial experiments the concentrations were selected to produce, if possible, acute effects after short exposures. Thereafter the exposure period was extended and the concentration lowered until the animals could survive 6-hour exposures, five days a week for up to four weeks. With liquids, the vapour pressure limited the range of concentrations which could be tested in these acute and subacute
experiments.
If at any stage effects were observed which could be attributed to the exposure, the experiment was repeated with progressively lower concentrations until a concentration was reached which was without effects on the animals.

Examinations

Observations and examinations performed and frequency:

The rats were weighed each morning, and their conditions and behaviour were recorded throughout the exposure period. Urine was collected overnight after the last exposure day for biochemical tests. The animals were left overnight with food and drink. On the following day the rats were anaesthetized with halothane and partially exsanguinated by heart puncture for haematological tests.

Sacrifice and pathology:

One day after the last exposure day rats were anaesthetized with halothane and partially exsanguinated by heart puncture for haematological tests. After a gross examination of the organs, the lungs were inflated with formol-saline and immersed in the same fixative. The following organs were also taken for microscopical examination after fixation in formol-corrosive: lungs, liver,kidneys, spleen, and adrenals; and occasionally heart, jejunum, ileum, and thymus.

Results and discussion

Results of examinations

Details on results:

At 250 ppm: Nose and eye irritation, rapid breathing, weight gain low and irregular. No change of haematological and clinical parameters in blood and urine. No pathological (macroscopical and microscopical) effects on organs were observed.

At 100 ppm: No toxic effects were observed.

Effect levels

1

Dose descriptor:

NOAEC

Effect level:

100 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: nose and eye irritation

2

Dose descriptor:

LOAEC

Effect level:

250 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: nose and eye irritation

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The NOAEC for repeated inhalation toxicity is considered to be 100 ppm (643 mg/m³).

Executive summary:

Short-term vapor inhalation toxicity was studied in rats with a constant flow pump for 3 wks, 5 d/w, 6 h/d. At 250 ppm (1608 mg/m³), nose and eye irritation and labored breathing were observed. The body weight gain was slow. There were no changes in the hematological parameters. No pathological (macroscopical and microscopical) effects on organs were observed. At 100 ppm (643 mg/m³), no toxic effects were observed.

Conclusion: The NOAEC for repeated inhalation toxicity is considered to be 100 ppm (643 mg/m³).