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Administrative data

Description of key information

LD50 oral on rat: 621-725 mg/kg (published data) 
LC50 inhalation on mice (2h): 7.57 mg/L (published data)
LD50 dermal on rabbit: 4600 mg/kg (published data)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
LD50
621 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion
Dose descriptor:
LD50
4 600 mg/kg bw

Additional information

Oral:

Two studies were selected as key studies (available in different publications) and give the following LD50 in rats by oral route: 621 and 725 mg/kg. Studies were well described and the reliability of these two studies is 2 according to Klimisch ranking.

 

Dermal:

Only one study was available and was considered as a key study. The reliability of this study is 2 according to Klimisch ranking. In this acute dermal toxicity study (Moreno, 1978), groups of 4 rabbits (sex unspecified) were dermally exposed to guaiacol at doses of 2500, 3530 and 5000  mg/kg bw. Dermal LD50 was 4600 mg/kg bw(95% C.I:3800-5400mg/kg).

 

Inhalation:

Only one study was available and was considered as a key study. The reliability of this study is 2 according to Klimisch ranking. In this acute inhalation toxicity study (Ostrovsky, 1964), groups of mice were exposed by inhalation route to guaiacol for 2 hours at concentrations of 2.03 to 17.19mg/L.The LC50 in mice was 7.57 mg/L for 2 hours(calculated as 3.78 mg/L for 4 hours).

 

Justification for classification or non-classification

Oral: Based on the LD50 value of 621 mg/kg bw/day,gaiacol is classified as harmful if swallowed (Xn, R22)according to annex VI of the Directive 67/548/EEC andas Acute Tox. Category 4, H302:Harmful if swallowedaccording to EU GHS criteria (Regulation (EC) n° 1272/2008 - Annex I). This classification is in accordance with the official one.

Dermal: Based on the dermal LD50 of 4600 mg/kg bw/day,gaiacol is not classified for dermal acute toxicityaccording to the Directive 67/548/EEC (Annex VI) and according to EU GHS criteria (Regulation (EC) n°1272/2008 - Annex I). This classification is in accordance with the official one.

 

Inhalation: Based of the LC50 of 7.57 mg/L calculated in mice for 2 hours of exposure (calculated as 3.78 mg/L for 4 hours) no conclusion on guaiacol classification can be drawn for this endpoint, since this study was performed in mice instead of rats and during only 2 hours instead of 4 as required in the OECD guideline.

However, gaiacol was not officially classified for this route of exposure.

 

Gaiacol is officially classified Xn R22 (Harmful if swallowed) in the Regulation (EC) n° 1272/2008 Annex VI table 3.2 and as Acute Tox. Category 4, H302: Harmful if swallowed according to the Regulation (EC) n° 1272/2008 Annex VI table 3.1.