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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

The endpoint 'Acute toxicity' is waived based on the classification as Skin Corr. 1B (H314). As supporting information several studies are available for the oral route and one study is available for the dermal route. The key results of these studies are as follows:

oral

Acute, oral, rat, LD50 = 980 mg/kg bw (Jenner, 1964)

dermal

Acute, dermal, rat, LD50 > 2000 mg/kg bw (Bomhard, 1986)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records
Reference
Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: sufficient documented for evaluation
Principles of method if other than guideline:
Groups of 10 young adult Osborne-Mendel rats evenly divided by sex were fastened for approximately 18 hr prior treatment. Animals had access to water at all times, and the food was replaced in cages as soon as animals received their respective doses. All doses were given by intubation. All animals were maintained under close observation for recording toxic signs and time of death. Such observation was continued until animals appeared normal and showed weight gain. The usual observation period was 2 weeks. LD50's were computed by the method of Lichtfeld & Wilcoxon (1949), J.Pharmacol. 96, p.99.
GLP compliance:
no
Test type:
other: no data
Species:
rat
Strain:
Osborne-Mendel
Sex:
male/female
Route of administration:
oral: gavage
Vehicle:
propylene glycol
Doses:
no data
No. of animals per sex per dose:
10
Control animals:
not specified
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
980 mg/kg bw
Mortality:
Death time: 4 hr-5 days.
Clinical signs:
other: Toxic signs: Depression, ataxia, coma on high doses
Interpretation of results:
Category 4 based on GHS criteria
Remarks:
EU GHS
Conclusions:
LD50 = 980 mg/kg bw.
Executive summary:

Method: 10 male and female rats received thymol as a 20% solution in propylene glycol per gavage.

Result: LD50 = 980 mg/kg bw.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
Value:
980 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Acute toxicity: via dermal route

Link to relevant study records
Reference
Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: according guideline 84/449/EWG
Guideline:
other: Directive 84/449/EWG
Principles of method if other than guideline:
Method: other: Directive 84/449/EWG
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Specific details on test material used for the study:
Thymol 99.5/99.6 % (peak area)
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
male and female Wistar rats, SPF, average weight 210 g (males) and 197 g (females), animals were housed in macrolon cages type II
Type of coverage:
occlusive
Vehicle:
other: Cremophor
Details on dermal exposure:
substance was individually prepared on an aluminium foil, mixed with cremophor and fixed on the animals by means of plaster
Duration of exposure:
24 h
Doses:
2000 mg/kg bw
No. of animals per sex per dose:
5
Control animals:
not specified
Details on study design:
animals were inspected daily for clinical signs
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: weighing before application, after 1 week and and at the end of the observation period of 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology
Statistics:
not necessary (limit test)
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Mortality:
no mortality
Clinical signs:
other: no symptoms of poisoning
Gross pathology:
no findings
Other findings:
a brownish discoloration on skin areas was observed at the application side on some animals

mortality: 0/10; no pathological changes (post observation time 14 days). After a single dose of 2000 mg/kg no signs of intoxication were observed. The application area showed a brownish discoloration  concerning 3 male and 2 female rats. The discoloration exists up to 4 days.

Interpretation of results:
other: EU GHS criteria not met
Conclusions:
results: LD50 > 2000 mg/kg bw; no pathological changes and no signs of intoxication were observed
Executive summary:

method: 2000 mg/kg bw of the test substance was applied occlusive for 24 h on 5 male and 5 female rats.

Post observation time was 14 days

results: LD50 > 2000 mg/kg bw; no pathological changes and no signs of intoxication were observed

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
2 000 mg/kg bw

Additional information

The endpoint 'Acute toxicity' is waived based on the classification as Skin Corr. 1B (H314). As supporting information several studies are available for the oral route and one study is available for the dermal route.

oral

For rats an LD50 = 980 mg/kg bw was identified (Jenner 1964), for mice the LD50 ranged from 640 mg/kg bw (Izeki, 1956) to 1800 mg/kg bw (McOmie, 1949) in several studies. For guinea pigs an LD50 of 880 mg/kg bw was determined (Jenner 1964).

dermal

For acute dermal toxicity an LD50 > 2000 mg/kg bw was found; in this study no pathological changes and no signs of intoxication were observed (Bomhard, 1986).

Justification for classification or non-classification

Based on the available data, the registered substance is classified for lethal effects following a single oral exposure as Acute Tox Cat. 4 (H302) according to Regulation (EC) No 1272/2008. This outcome also correlates with the harmonised CLP classification of thymol for acute toxicity (H302).