Tin sulfide (Sn2S3)

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics

Type of information:

other: Expert Statement

Adequacy of study:

key study

Study period:

2015-11-23

Conclusions:

Interpretation of results: no bioaccumulation potential based on study results

Executive 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 tin sulfides and in this case ditin trisulfide (Tin (II,IV) sulfide) is assumed to be very low. This conclusion is confirmed by the literature on oral absorption of inorganic tin compounds.

 

Due to the physical state, the molecular weight, the low 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 tin sulfides and in this case ditin trisulfide is assumed to be very low.

 

Even if 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 the low vapour pressure and the tendency of ditin trisulfide particles to agglomerate and depositas well as the absence of clear systemic toxicity in acute toxicity studies with tin sulfides do not favour the respiratory uptake.

 

Based on the low water solubility, but mainly based on the absence of target organs or signs of toxicity in an acute and a repeated dose toxicity study with tin sulfides in rats up to the limit concentration, distribution of tin sulfides and in this case ditin trisulfide was considered minimal. Even if literature describes that tin may accumulate mainly in bones, but also in kidneys, liver and lung this is assumed to be of minor interest for insoluble tin sulfides, e.g. ditin trisulfide,due to the low absorption.

 

There is no direct indication of relevant bioaccumulation potential of tin sulfides, e.g.ditin trisulfide. However, literature describes that tin may accumulate mainly in bones, but also in kidneys, liver and lung. But it has been shown that water soluble tin salts are eliminated within short half-times. Taking into account that absorption of insoluble tin sulfides in this case ditin trisulfideis considered to be very low, accumulation is not considered to be relevant.

 

The oral absorptionof tin sulfides and in this case ditin trisulfideis 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 and bile. This is confirmed by literature.

Description of key information

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 tin sulfides and in this case ditin trisulfide (Tin (II,IV) sulfide) is assumed to be very low. This conclusion is confirmed by the literature on oral absorption of inorganic tin compounds.

Due to the physical state, the molecular weight, the low 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 tin sulfides and in this case ditin trisulfide is assumed to be very low.

Even if 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 the low vapour pressure and the tendency of ditin trisulfide particles to agglomerate and deposit as well as the absence of clear systemic toxicity in acute toxicity studies with tin sulfides do not favour the respiratory uptake.

Based on the low water solubility, but mainly based on the absence of target organs or signs of toxicity in an acute and a repeated dose toxicity study with tin sulfides in rats up to the limit concentration, distribution of tin sulfides and in this case ditin trisulfide was considered minimal. Even if literature describes that tin may accumulate mainly in bones, but also in kidneys, liver and lung this is assumed to be of minor interest for insoluble tin sulfides, e.g. ditin trisulfide, due to the low absorption.

There is no direct indication of relevant bioaccumulation potential of tin sulfides, e.g. ditin trisulfide. However, literature describes that tin may accumulate mainly in bones, but also in kidneys, liver and lung. But it has been shown that water soluble tin salts are eliminated within short half-times. Taking into account that absorption of insoluble tin sulfides in this case ditin trisulfide is considered to be very low, accumulation is not considered to be relevant.

The oral absorption of tin sulfides and in this case ditin 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 and bile. This is confirmed by literature.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

5

Absorption rate - dermal (%):

10

Absorption rate - inhalation (%):

1

Additional information

Additional assessment based on literature of tin salts:

For the general population, the major source of tin is the diet. By comparison, drinking water and inhaled air contribute insignificant amounts. From data on mean tin intake from food for the populations of seven countries (Australia, France, Japan, Netherlands, New Zealand, the United Kingdom, and the USA), JECFA (2001) concluded that tin intakes ranged from < 1 up to 15 mg/person per day. Certain individuals who routinely consume canned fruits, vegetables, and juices from unlacquered cans could ingest 50-60 mg of tin daily (Johnson & Greger, 1982; Sherlock & Smart, 1984; JECFA, 2001). Those who consume about four servings of food stored in open unlacquered cans, on a daily basis, might consume in the region of 200 mg of tin per day (Greger & Baier, 1981; JECFA, 2001). In humans and laboratory mammals, absorption of inorganic tin from the gastrointestinal tract is low (generally less than 5 %), in particular for practically water insoluble compounds such as tin(ll) sulfide, but is influenced by dose, anion (compound solubility), and the presence of other substances. Unabsorbed ingested tin is mostly (95-99%) excreted in the faeces within 48 h. Absorbed tin distributes mainly to the bone, but also to the lungs, liver, and kidneys. Limited evidence suggests that inorganic tin does not readily cross the blood-brain barrier. Absorbed tin is mainly excreted in the urine, with some additional biliary excretion occurring. In mice, the biological half-life of absorbed inorganic tin was approximately 30 days. There is little or no evidence that practically water insoluble tin compounds pose any significant health risk at the exposure levels found in the work environment (European Commission, 2003).