Dibismuth trisulphide

Endpoint summary

Description of key information

A basic toxicokinetics assessment of dibismuth trisulfide was based on physicochemical  and toxicological data and literature of dibismuth trisulfide, as well as on read across data from bismuth. From these data, absorption was assessed to be very low, and the oral  route is considered as most appropriate route for testing systemic toxicity. Distribution, metabolism and elimination were also shortly discussed, but not elaborated much into detail based on the limited absorption.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

5

Absorption rate - dermal (%):

5

Absorption rate - inhalation (%):

1

Additional information

SUMMARY

 

Based on the physical form and low water solubility, but mainly on the absence of toxicity in acute and repeated dose oral toxicity studies, oral absorption of dibismuth trisulfide is assumed to be very low. This conclusion is confirmed by the literature on oral absorption of insoluble bismuth compounds.

 

The physical state, the molecular weight, the water solubility, the vapour pressure, but mainly the absence of toxicity in acute dermal animal testing and the absence of irritating or corrosive and sensitizing potential the dermal absorption of dibismuth trisulfide is assumed to be very low.

 

The low vapour pressure and the tendency of dibismuth trisulfide particles to agglomerate and deposit do not favour the respiratory uptake, whereas the particle size and the low water solubility favour the assumption that particle can be absorbed on different stages of the stages of the respiratory tract and via the gastrointestinal tract. However,the absence of toxicity in acute inhalation toxicity and acute and repeated dose oral toxicity studies, the respiratory and oral absorption of dibismuth trisulfide is assumed to be very low.

 

Based on the low water solubility, but mainly based on the absence of target organs or signs of toxicity in a repeated dose toxicity study with the Read-Across substance bismuth in rats up to the limit concentration, distribution was considered minimal. Data from literature indicates accumulation in the kidney, however this is not considered to be relevant since the absorption of poorly water-soluble inorganic bismuth compounds is considered to be low.

 

There is no direct indication of bioaccumulation potential of dibismuth trisulfide in lung, adipose tissue, bone or stratum corneum. However, literature describes that bismuth compounds may accumulate in the kidney. Taking into account that absorption of dibismuth trisulfide is considered to be very low, accumulation is not considered to be relevant.

 

Since the oral absorption of dibismuth trisulfide is very low, therefore the estimated favoured excretion route is the faecal route. However, very small quantities of absorbed and therefore dissolved parts are excreted via urine.