Bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

Endpoint summary

Description of key information

The substance bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc is a mono constituent substance. No studies on the toxicokinetics of the substance are available. Only limited data has been provided by ECHA via an inquiry result. No human data is available and the toxicokinetic analysis is based on physicochemical data and other relevant data. Based on this data, oral absorption can be expected, there is potential for distribution and metabolism and excretion may be affected by hepatic toxicity.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

50

Absorption rate - dermal (%):

50

Absorption rate - inhalation (%):

100

Additional information

Absorption

The substance has a molecular weight of 564.05 g/mol, a solubility in water of 187.7 mg/L pH 7 at 20.0°C and a log octanol/water partition coefficient value of log10 Pow of 2.32 at 18.0°C; with these properties the substance is likely to absorbed orally from the gastro-intestinal tract. The systemic toxicity noted in the acute oral toxicity and subacute oral toxicity studies confirms this assumption. For risk chemical safety assessment purposes, a default oral absorption of 50% is accepted.

As a powder, the D50 of 17.44 µm and log10 Pow of 2.32 indicates the potential for respiratory inhalation and absorption. No inhalational toxicity data is available for the powder form of the substance. For risk chemical safety assessment purposes, the default inhalation absorption rate of 100% is accepted.

Based on the physicochemical properties of the substance (molecular weight, log10 Pow value, chemical structure), dermal absorption of the substance is expected to be low. However, the ECHA guidance criteria (Chapter R.7C) state that 10 % dermal absorption is used when the molecular weight of the substance is > 500 and the log Pow is <-1 or >4, otherwise 100 % dermal absorption is used. In general, dermal absorption will not be higher than oral absorption, so a dermal absorption rate of 50% will be used for chemical safety assessment.

Metabolism, Distribution and Excretion

Due to its water solubility and lipophilicity the substance may partition into tissues. Indications of hepatic toxicity in the oral repeated dose studies suggest that the metabolism of the substance may be compromised. There is no direct evidence to indicate the route of excretion of the substance. The substance is expected to be excreted in the faeces due to its molecular weight.