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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to OECD guideline, no GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Principles of method if other than guideline:
Groups of 10 Wistar rats/sex were exposed to a liquid aerosol of the test substance (50%, w/w) using a head-nose inhalation system.
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Caprolactam

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Dr. K. Thomae GmbH, Biberach
- Age at study initiation: 8 weeks
- Mean weight at study initiation: male 250 g (224-268 g) female 178 g (161-192 g)
- Diet (e.g. ad libitum): Kliba labor diet
- Water (e.g. ad libitum): tap water


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12/12


Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
nose/head only
Vehicle:
other:
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Nose/head - inhalation system INA 20, BASF AG
- Exposure chamber volume: 55 l
- Method of holding animals in test chamber: animals were kept in the tube with muzzle projecting in the inhalation chamber
- System of generating particulates/aerosols: Generatorsystem- infusion pump INFU 362, membrane dose pump Duramat. The aerosol was generated using compressed air.
- Temperature in air chamber: 19-25 °C


TEST ATMOSPHERE
- Brief description of analytical method used: Quantitative determination of aerosol concentration was performed using gas chromatography. For this the aerosol probes were dissolved in 10ml Ethanol.
- Samples taken from breathing zone: yes
- Nominal concentrations were calculated using the substance consumption and the air volume.
- probes for particle size analysis were taken from 30 min after onset of exposure

VEHICLE
- Concentration of test material in vehicle: 50% (w/v) in water




Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
5.25, 8.35 and 10.12 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: Body weight of individual animals was measured before treatment and after 7 and 14 days of treatment, daily clinical inspection
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology (anatomical/pathological)
Statistics:
According to the probit analysis of D.J. Finney, 1-150 (Syndics of the Cambridge University Press, 1971).

Results and discussion

Effect levelsopen allclose all
Sex:
male/female
Dose descriptor:
LC50
Effect level:
8.16 mg/L air
95% CL:
7.2 - 9.23
Exp. duration:
4 h
Sex:
male
Dose descriptor:
LC50
Effect level:
ca. 9.6 mg/L air (analytical)
Exp. duration:
4 h
Sex:
female
Dose descriptor:
LC50
Effect level:
7.08 mg/L air (analytical)
95% CL:
5.87 - 8.1
Exp. duration:
4 h
Mortality:
see free text
Clinical signs:
other: Symptoms during exposure: closure of eyelid, irregular respiration, escape reaction Symptoms after exposure: dyspnoea, piloerection, intermittent respiration, bloody nose and eye discharge, tremor. Clinical signs were reversible after 5 days (low dose), 7
Body weight:
No effects on body weight gain were observed
Gross pathology:
Severe hyperemia in lungs and liver adiposis in some perished animals. No abnormalities in the sacrificed animals
Other findings:
- Histopathology: fatty degeneration in the liver and ischemic tubulonephrosis in the cortex of the kidney of 1 deceased animal. No lesions were observed in the sacrificed animals.

Any other information on results incl. tables

Dose (mg/l)

Sex

Mortality within

4 h

1 day

14 days

5.25

M

0/10

1/10

1/10

F

0/10

1/10

1/10

8.25

M

0/10

1/10

1/10

F

0/10

7/10

7/10

10.12

M

2/10

7/10

7/10

F

1/10

10/10

10/10

Applicant's summary and conclusion