Registration Dossier

Administrative data

Description of key information

With regard to the acute toxicity assessment of the pigment, the assessment and corresponding data are primarily based on data on magnetite and on lead even though the pigment has shown to have very low overall bioavailability (PBET-extraction studies and systematic occupational exposure measurements among the regular employees at the production site).

For lead all health endpoints of concern are manifestations of systemic effects and are independent of exposure route, while the extremely low water solubility for magnetite (virtually insoluble at all physiological pH), renders the inhalation route to be potentially important to assess.

Lead toxicity in humans after true acute exposures is limited and, when documented, is generally under conditions that yield sub-chronic or chronic exposures. This finding is not unexpected given the pharmacokinetics of lead uptake into the body. Lead uptake is generally quite low and heavily reliant upon easily saturable active transport mechanisms. Once saturation of these uptake mechanisms has occurred, uptake proceeds by inefficient passive diffusion. The uptake of lead is thus highly non-linear as a function of dose with uptake efficiency declining with the amount of lead administered to a test animal or an exposed human. Although toxic under chronic exposure situations, the acute toxicity of lead oxide is low.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
2 000 mg/kg bw
Quality of whole database:
good

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
discriminating conc.
Value:
640 mg/m³
Quality of whole database:
good

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
2 000 mg/kg bw
Quality of whole database:
good

Additional information

Justification for classification or non-classification