3,4-dihydro-2-methoxy-2H-pyran

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Reference 2

Reference Type:

publication

Title:

3,4-Dihydro-2-methoxy-2H-pyran (CAS No. 4454-05-1)

Author:

OECD

Year:

2003

Bibliographic source:

cited in OECD SIDS 3,4-Dihydro-2-methoxy-2H-pyran for SIAM 16, 27-30 May 2003, Paris, France.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3,4-dihydro-2-methoxy-2H-pyran

EC Number:

224-698-3

EC Name:

3,4-dihydro-2-methoxy-2H-pyran

Cas Number:

4454-05-1

Molecular formula:

C6H10O2

IUPAC Name:

2-methoxy-3,4-dihydro-2H-pyran

Details on test material:

- Name of test material (as cited in study report): Methoxydihydropyran
- Physical state: clear colourless liquid
- Analytical purity: ca. 95%
- Impurities (identity and concentrations): 4% dimer acrolein, traces of acrolein and methylvinylether
- Lot/batch No.: not reported
- Stability under test conditions: not reported
- Storage condition of test material: not reported

Specific details on test material used for the study:

purity: ca. 95%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPRA, 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:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
Exposure concentrations of the test substance were generated by pumping the liquid test substance at constant rates into glass vaporization flasks heated to 60°C, the vapors were mixed with fresh air and transmitted to the exposure chamber.

CHAMBER DESCRIPTION
- Exposure apparatus: Inhalation chamber made from glass and steel
- Exposure chamber volume: 200 l

TEST ATMOSPHERE
- Brief description of analytical method used: Gaschromatography (HP 5840A)
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Remarks:

The measurement of nominal concentration of 12.0 mg/l was 6.1 mg/l.

Duration of exposure:

4 h

Concentrations:

6.1 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
- Frequency of observations and weighing: clinical signs daily, body weight before, 7 days after and at the end of the experiment.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

Statistical calculations were made using Binomial test after Wittig (Mathematische Statistik 1974, p 32 - 35).

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 6.1 mg/L air (analytical)

Exp. duration:

4 h

Mortality:

No mortality was observed.

Clinical signs:

other: The signs observed were reddish watery nasal secretions, later reddish sticky eyes and nose, eyelid closure, intermitent respiration, staggering gait, ruffled and sticky fur coat. The signs were reversible within 8 days of observation period.

Body weight:

There was no difference in the body weight gain between the test animals and historical controls.

Gross pathology:

No alterations were observed.

Applicant's summary and conclusion

Executive summary:

This study was conducted as limit test comparable to OECD guideline 403 and is reliable without restrictions. Ten males and ten females were exposed to vapors of the test substance at concentration of 6.1 mg/l (analytical). No mortality was observed. The signs observed were reddish watery nasal secretions, later reddish sticky eyes and nose, eyelid closure, intermitent respiration, staggering gait, ruffled and sticky fur coat. The signs were reversible within 8 days of observation period. There was no difference in the body weight gain between the test animals and historical controls. No alterations were observed at necropsy.

Conclusion: According to the test results, the LC50 of the test substance is >6.1 mg/l for male and female animals.