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Administrative data

Description of key information

Acute toxicity: Oral

Key study: Standard acute method. The LD50 in rats was > 5000 mg/kg-bw.

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:
key study
Study period:
1994
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The paper by Hayashi et al. was published 1994 in a Japanese journal as part of a series of publications on Tazobactam. Only the summary and the Tables are provided in English. Therefore the evaluation restricts to the English parts of the paper. The report provides in the summary and the relevant Table 2 only few details on the method used. Missing information, which might appear in the Japanese text, are: Purity of the test substance; no evidence of the compliance with GLP; age of the animals; etc. The results reported are consistent for the various route of administration and also between the two species rats and mice (no dose and mortality is reported for dogs in the summary). The results are also consistent with those of repeated dose studies reported in the same journal. The NOAEL in the 6-months study in rats after intraperitoneal administration is 40 mg/kg/day. There is enough weight of evidence to state that Tazobactam acid has not to be classified, based on results of an acute oral toxicity study with rats, even if a lot of details of the method is missing in the legible description of the study. A repetition of the available but only partly legible study is therefore not justified; also when observing animal welfare issues.
Reason / purpose for cross-reference:
reference to same study
Principles of method if other than guideline:
Standar acute method
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
yes
Species:
rat
Strain:
Crj: CD(SD)
Sex:
male/female
Details on test animals or test system and environmental conditions:
No details are provided in the English text. The Japanese text of the publication obviously contains some information.
Doses:
5000 mg/kg.
No. of animals per sex per dose:
7.
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days.
Statistics:
Not relevant.
Key result
Sex:
male
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Mortality:
No mortality was observed.
Clinical signs:
Clinical sign was soft stool.
Interpretation of results:
GHS criteria not met
Remarks:
CLP Implementation.
Conclusions:
There is enough weight of evidence to state that Tazobactam acid has not to be classified, based on results of an acute oral toxicity study with rats, even if a lot of details of the method is missing in the legible description of the study.
Executive summary:

The LD50 is >5000 mg test substance / kg bw after oral administration to rats.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
5 000 mg/kg bw
Quality of whole database:
Key study is of Klimisch score = 2.

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Although the studies are only partly legible, because they were written in Japanese, and because the publication do not give extensive information on the methods used, there is enough weight of evidence that Tazobactam acid can be considered to be of low acute toxicity.

Studies with other administration routes, which are more relevant for pharmaceuticals and with other species confirm the low acute toxicity of the notified substance.

Justification for classification or non-classification

Based on the available information, the substance is not classified for acute toxicity according to CLP Regulation.