ε-caprolactam

Respiratory sensitisation

Administrative data

Endpoint:

respiratory sensitisation: in vivo

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 Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Principles of method if other than guideline:

Sensitization reactions to the test substance aerosols were observed by exposing groups of 4 guinea pigs for 30 min/day for 5 consecutive days to 3 aerosol concentrations (3, 10 and 30 mg/m³ which corresponds to 0.003, 0.01 and 0.03 mg/l).
Each animal was placed in a whole body plethysmograph attached to a primary chamber. This device can detect pressure changes induced by the breathing activity of the test animals.
On days 19, 26, 33 and 40, all three groups of animals were challenged with CO2, then given a 30 minute challenge of 30 mg/m³ test substance and another CO2 challenge 45 minutes later. After the last challenge, lungs were removed from all animals and grossly examined.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

ε-caprolactam

EC Number:

203-313-2

EC Name:

ε-caprolactam

Cas Number:

105-60-2

Molecular formula:

C6H11NO

IUPAC Name:

azepan-2-one

Specific details on test material used for the study:

- Name of test material (as cited in study report): E-Caprolactam
- Physical state: white flakes
- Lot/batch No.: D344A441 from BASF Corp. Chemical Division, Freeport, Texas

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hazleton Labs Inc., Denver, PA
- Weight at study initiation: 381-455 g
- Diet (e.g. ad libitum): Ralston Purina Guinea Pig Chow
- Water (e.g. ad libitum): Tap water
- Acclimation period: 12 days

ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Route of induction exposure:

inhalation

Route of challenge exposure:

inhalation

Vehicle:

water

Concentration:

3, 10 and 30 mg/m³ which corresponds to 0.003, 0.01 and 0.03 mg/L

No. of animals per dose:

4

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 5
- Exposure period: 30 min
- Each animal was placed in a whole body plethysmograph attached to a primary chamber. A sensitive differential pressure transducer (Gaeltec 8T-2) was attached to each whole body plethysmograph. With each breath, a pressure change (AP) was created in the whole body plethysmograph and detected by the transducer.
- A 15% solution of caprolactam was prepared in distilled water. The solution was placed in a 30 ml syringe with a 20g needle attached. The syringe was fitted into a Harvard (Model 975) compact syringe pump which was set to deliver at 0.7 ml/minute. It was connected to the aerosol generator. The aerosol generator was pressurized at 15 psi with dry air. An additional 10 L/min of dry air was introduced at the side port of the Y tube at the entrance of the primary chamber. Thus, dry particles of caprolactam were produced for inhalation by the animals. The various concentrations of caprolactam were obtained by varying the exhaust airflow of the primary chamber from 20 L/min to 70 L/min.


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: On days 19, 26, 33 and 40
- Exposure period: 30 min
- All three groups of animals were challenged with CO2, then given a 30 minute challenge of 30 mg/m³ caprolactam and another CO2 challenge 45 minutes later.

Results and discussion

Any other information on results incl. tables

FIRST 5 DAYS OF CONSECUTIVE EXPOSURES:
no significant respiratory responses to the test substance. Only one cough was noted during the entire series of experiments. Therefore, there was no evidence of any kind of acute irritating or bronchoconstricting properties.

CHALLENGE DAYS:
no immediate reaction, no evidence of an immediate hypersensitivity reaction and no abnormal respiratory responses to the test substance. Ventilatory response to the CO2 challenges was normal.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

Under the conditions of this experiment, the test substance can not induce respiratory sensitization reaction even at the highest concentration (30 mg/m3) tested.

Executive summary:

Sensitization reactions to the test substance aerosols were observed by exposing groups of 4 guinea pigs for 30 min/day for 5 consecutive days to 3 aerosol concentrations (3, 10 and 30 mg/m³ which corresponds to 0.003, 0.01 and 0.03 mg/l). Each animal was placed in a whole body plethysmograph attached to a primary chamber. This device can detect pressure changes induced by the breathing activity of the test animals.

On days 19, 26, 33 and 40, all three groups of animals were challenged with CO2, then given a 30 minute challenge of 30 mg/m³ test substance and another CO2 challenge 45 minutes later. After the last challenge, lungs were removed from all animals and grossly examined. Under the conditions of this experiment, the test substance can not induce respiratory sensitization reaction even at the highest concentration (30 mg/m3) tested.