Registration Dossier

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: Published non-standard Russian study: translation provided.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
On the Toxicity of Dimethyl Terephthalate
Author:
Sanina YP & Kochetkova TA
Year:
1963
Bibliographic source:
Toksikol. Novykh. Prom. Khim. Veshchestv, 5, 107-123 (1963)

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The effect of a single inhalation exposure to terephthalate vapour was tested on rats. The animals were placed for two hours into a 100-L hexahedral chamber.
GLP compliance:
no
Remarks:
: older study, pre-dates GLP
Test type:
other: non-standard design using a 2-hour exposure
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Dimethyl terephthalate crystals

Test animals

Species:
rat
Strain:
not specified
Sex:
not specified
Details on test animals and environmental conditions:
White rats were used in all the inhalation studies. A 100 L hexahedral chamber was used as the exposure chamber in all tests.

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
Dimethyl terephthalate vapours were generated by heating dimethyl terephthalate crystals in a metal vessel on an electric stove at 100 to 110°C. Dimethyl terephthalate vapours were delivered via a tube into the top of the exposure chamber containing the animals. The temperature in the chamber ranged from 25 to 29ºC.

In the single exposure experiment, the rats were exposed to the vapours for 2 hours.

Based on the thermal properties of dimethyl terephthalate (melting and boiling at 141 and 284°C, respectively, without reported evidence of decomposition), it is unlikley that thermal decomposition products were formed by the procedure used to generate the inhalation atmosphere.
Analytical verification of test atmosphere concentrations:
not specified
Duration of exposure:
2 h
Concentrations:
6 mg/L
No. of animals per sex per dose:
12 rats werere used (6 in the experiment and 6 as a control)
Control animals:
yes
Details on study design:
Single exposure experiment: Twelve white rats (six used in experiment, six used as a control) were exposed to dimethyl terephthalate vapours for two hours. During this two hours, the rats were observed. Post exposure observation lasted for 14 days.
No further details

Statistics:
Not reported.

Results and discussion

Preliminary study:
No preliminary study
Effect levels
Sex:
not specified
Dose descriptor:
LC50
Effect level:
> 6 mg/L air (nominal)
Based on:
test mat.
Exp. duration:
2 h
Remarks on result:
other: No deaths
Mortality:
No mortalities
Clinical signs:
other: Ten to twenty minutes after being subjected to the action of dimethyl terephthalate, the animals were in an excited state (they rubbed their noses vigorously, their eyes were closed). This state lasted until the end of exposure. Acute conjunctival hyper
Body weight:
No abnormality in body weight compared to the control group was noted in the test animals.
Gross pathology:
No autopsies performed.
Other findings:
A peripheral blood analysis revealed changes in the red blood; the haemoglobin content was lower by 15 to 25% on average and the erythrocyte count decreased from 9,000,000 to 7,000, 000 to 6,000,000 to 5,000,000.

Any other information on results incl. tables

No further information.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
During single exposure to condensation aerosol and vapours of dimethyl terephthalate a pronounced irritating effect on the conjunctiva and respiratory tract accompanied by moderate hemodynamic disorders was observed. The LC50 was estimated to be greater than 6 mg/L.
Executive summary:

In a published acute inhalation toxicity study, a group of 12 rats was exposed (whole body) to DMT vapour at a concentration of 6 mg/L for 2 hours. During the exposure to condensation aerosol and vapours of dimethyl terephthalate a pronounced irritating effect on the conjunctiva and respiratory tract accompanied by moderate hemodynamic disorders was observed. The LC50 was estimated to be greater than 6 mg/L.