[carbonato(2-)]hexadecahydroxybis(aluminium)hexamagnesium

Endpoint summary

Description of key information

Short description of key information on bioaccumulation potential result: 
The following values will be used for route-to-route extrapolation:
- oral absorption: 10%
- dermal absorption: 1% 
- inhalation absorption: 1%

Key value for chemical safety assessment

Absorption rate - oral (%):

10

Absorption rate - dermal (%):

1

Absorption rate - inhalation (%):

1

Additional information

Based on the Risk Assessment of Aluminium-Magnesium-Zinc-Carbonate-Hydroxide, an analogue substance, performed by the Dutch Competent

Authorities (BMS071023.03, d.d. 23-10-07), the following values are considered for absorption:

- oral absorption: 50%

- dermal absorption: 1% (based on the physico-chemical properties)

- inhalation absorption: 1% (considering the particle size inhalation exposure will be negligible)

However, the value of 50% for oral absorption is considered rather high estimate. In general this value is taken if no data are available on oral bioavailability. The value of 50% is an arbitrary choice that recognizes that the GI tract is designed to favor the absorption in ingested substances into the body but that, in most cases, not all of the ingested material will be bioavailable. If there is evidence to suggest poor oral bioavailability, for example the substance is a poorly soluble particulate, then it may be more appropriate to assume that only 10% of the administered dose is systemically available (IGHRC Guidelines, 2006).

In case of P93, the very low water solubility (< 9 µg/L) and the low solubility in n-octanol (< 0.47 mg/L), an oral absorption of 10% might be considered more appropriate for risk assessment purposes.

Therefore the following values will be used for route-to-route extrapolation:

- oral absorption: 10%

- dermal absorption: 1%

- inhalation absorption: 1%