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Administrative data

Description of key information

Based on the only study available with reliability 2, a LOAEL of 1500 mg/kg/day was identified in rats after oral route exposure to guaiacol, the NOAELis lower than 1500 mg/kg (published data).
No data are available by dermal route and by inhalation.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Dose descriptor:
1 500 mg/kg bw/day
Study duration:

Mode of Action Analysis / Human Relevance Framework

Additional information

Only data on oral route are available. Three studies are available, but only one was considered as reliable and was selected as a key study.

In this subacute toxicity study (Kawabe, 1994) Gaiacol was administered to 5 Fisher 344 male rats per dose in diet at dose levels of 2%, corresponding to 1500 mg/kg bw/day (estimated by calculation), during 28 days.

The body weights of animals treated with guaiacol were 10 to 33% less than the basal diet alone values.

Relative liver and kidney weights were increased by guaiacol. Significant increase in the thickness of the forestomach mucosa in the prefundic or mid regions was observed in rats treated with gaiacol. Forestomach is specific to rodents. Therefore, the thickness increase of the forestomach observed in rats is not physiologically relevant to humans. In the glandular stomach and in the oesophagus, either thickness or labelling indices were significantly increased in rats given guaiacol.

Based on this study, a LOAEL of 1500 mg/kg bw/day (the only tested dose) was identified in rats for an increase of relative liver and kidney weight and for a significant increase in the thickness of glandular stomach and oesophagus.

Justification for classification or non-classification

Taking into account the overall data, the repeated dose toxicity of guaiacol by oral route seems to be low. Therefore, no classification for this endpoint is required.