Bismuth

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

13.1 mg/m³

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Acute/short term exposure

DNEL related information

Additional information - workers

There is one repeated dose oral toxicity study available aimed to characterise the potential toxic effects of bismuth metal following oral administration for 28 days at dose levels of 0, 40, 200 and 1000 mg/kg bw daily in male and female Sprague-Dawley rats with a recovery period of 14 days.The results did not indicate any changes attributed to treatment with bismuth metal in either males or females in the dose groups up to 1000 mg/kg. Thus, a NOAEL of 1000 mg/kg bw/d was established for bismuth metal based on the lack of toxicologically relevant effects at the highest dose tested and was selected as starting point for DNEL derivation.

 

Modification of the dose descriptor is necessary, because the routes of exposure are different between animals (oral) and humans (inhalation). For this purpose the default respiratory volume for the rat corresponding to the daily duration of human exposure is considered in the first step, followed by a correction for the difference between respiratory rates of workers under standard conditions and under light activity in the second step.

The following corrected NAEC_inhalation(no adverse effects concentrations) is calculated for humans (for details on the calculation refer to the report “Derivation of DENLs for bismuth metal and dibismuth trioxide” attached to the dossier):

Bismuth metal: 1763 mg/m³

In principle, further correction for differences in the rates of absorption for the oral and the inhalation routes in rats and humans can be considered. However, because oral absorption is very low in rats and can per default be assumed at about 0.5 %, and absorption in human following the inhalation route is calculated to be in a similar range (0.5 and 0.6 %, respectively) for bismuth metal and dibismuth trioxide (see EBRC report 2010, Derivation of oral, dermal and inhalation absorption factors for bismuth metal and bismuth compounds; IUCLID section 7.1), no further correction is considered.

For more details refer to the report "Derivation of DNELs for bismuth metal and dibismuth trioxide" attached to technical dossier.

General Population - Hazard via inhalation route

Systemic effects

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Acute/short term exposure

DNEL related information

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

13.3 mg/kg bw/day

Acute/short term exposure

DNEL related information

Additional information - General Population

There is one repeated dose oral toxicity study available aimed to characterise the potential toxic effects of bismuth metal following oral administration for 28 days at dose levels of 0, 40, 200 and 1000 mg/kg bw daily in male and female Sprague-Dawley rats with a recovery period of 14 days.The results did not indicate any changes attributed to treatment with bismuth metal in either males or females in the dose groups up to 1000 mg/kg. Thus, a NOAEL of 1000 mg/kg bw/d was established for bismuth metal based on the lack of toxicologically relevant effects at the highest dose tested and was selected as starting point for DNEL derivation.

Further modification of the dose descriptors is not necessary, because the routes of exposure are similar in animals (oral) and humans (oral).

 

For more details refer to the report "Derivation of DNELs for bismuth metal and dibismuth trioxide" attached to technical dossier.