Chlorocresol

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

repeated dose toxicity: inhalation

Remarks:

other: no data

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

publication

Title:

Repeated facial palsies after chlorocresol inhalation

Author:

MARTIN DOSSING, CHRISTIAN HERTEL WULFF, POUL ZANDER OLSEN

Year:

1986

Bibliographic source:

Journal of Neurology, Neurosurgery, and Psychiatry 1986;49:1452-1454

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other:

Principles of method if other than guideline:

The effect of exposure to chlorocresol was studied in 42 years old female

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chlorocresol

EC Number:

200-431-6

EC Name:

Chlorocresol

Cas Number:

59-50-7

Molecular formula:

C7H7ClO

IUPAC Name:

4-chloro-3-methylphenol

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): chlorocresol
- Substance type: Organic
- Physical state: solid

Test animals

Species:

other: Human

Sex:

female

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

not specified

Vehicle:

other: water

Details on inhalation exposure:

A few drops of a 0-1% concentration of chlorocresol diluted in water was poured into a sink, the cold tap was turned on to ensure a water born aerosol and the patient was placed near the sink.

Duration of treatment / exposure:

3 min

Doses / concentrations

Remarks:

Doses / Concentrations:
0.1%
Basis:

Control animals:

no

Examinations

Observations and examinations performed and frequency:

NEUROBEHAVIOURAL EXAMINATION: Yes

Results and discussion

Results of examinations

Clinical signs:

not examined

Mortality:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Details on results:

NEUROBEHAVIOUR
partial left-sided facial palsy occurred preceded by a feeling of pins and needles in the left cheek and temporal region. The weakness only affected the left orbicularis oris which was severely paretic. The philtrum was pulled 3-5 mms to the right (fig). There was no weakness of eye closure nor of the musculature of the forehead. The tear production of the left eye was unaffected. The rest of the neurological examination remained normal. After half an hour the facial palsy gradually resolved.

Effect levels

Dose descriptor:

LOAEL

Effect level:

1 other: %

Based on:

test mat.

Sex:

female

Basis for effect level:

other: partial left-sided facial palsy occured

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The LOAEL value of chlorocresol in 42 years old human female was observed at dose concentration of 1%

Executive summary:

A few drops of a 0-1% concentration of chlorocresol diluted in water was poured into a sink, the cold tap was turned on to ensure a water born aerosol and the patient was placed near the sink. After approximately 3 minutes a partial left-sided facial palsy occurred preceded by a feeling of pins and needles in the left cheek and temporal region. Only muscles around the left side of the mouth were affected. On neurophysiological testing during chlorocresol provocation the only abnormality was a loss of motor units during maximal contraction of the left orbicularis oris muscle. This could be explained by a peripheral as well as a central effect. Extensive electrophysiological examination without chlorocresol provocation excluded a preexisting generalized nerve disorder and other diagnostic procedures did not give evidence of pathology involving the left facial nerve. A hyperreactive mechanism causing a transient block of the left facial nerve is proposed. Hence the LOAEL was considered to be 1%