Tributyltin chloride

Endpoint summary

Description of key information

In an acute oral study in the rat (GU Project No: 821572) the LD50's for the test material were determined to be 101, 113 & 101 mg/kg bw for males, females and both sexes respectively. According to EU interpretation this test material is classed a toxic.

The symptoms observed include Dyspnoea, exophthalmus, ruffled fur and curved body position. Other symptoms observed include diarrhoea, salivation and sedation.

At necropsy, dilatation of parts of the digestive tract (small intestine, large intestine) was found by most of the mortally intoxicated rats in the four higher dose groups. This was not observed by the animals which recovered before terminal sacrifice.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

101 mg/kg bw

Additional information

Oral toxicity:

In the key study (Dr. P. Thevenaz, 1983), the study was conducted according to methods comparable to OECD 401.

The reliability rating for this study is 2, according to the criteria of Klimisch, 1997 as this is a study conducted at a Ciba-Geigy Laboratory using methodology similar to recognised methods, however no purity or GLP data was presented. This study is considered the most relevant and reliable study for this endpoint as all of the supporting information comes from literature papers or other less reliable sources, therefore this study will be used for classification purposes for this endpoint.

- In the Günzel (1969) paper, a study was conducted accoding similar principles to OECD 401, except the test was only run for 8 days. There was no purity or GLP data.

The LD50 of tributyltin chloride in the rat was determined to be 122 mg/kg. After application of 62.0 - 250 mg/kg general apathy was seen, later the animals were sporadically moribund and died 24 hours to 6 days after application.

A reliability rating of 2 was assigned to this study, according to the criteria of Klimisch, 1997 as although there was limited information on test material and no information on GLP, the methodolgy is well documented.

- In the Smith et al (1978) paper, the LD50 values for acute toxicity to rats for tributyltin dichloride range from 122 to 349 mg/kg.

A reliability rating of 4 was assigned to this paper, according to the criteria of Klimisch, 1997 as details of the toxic effects were not reported other than the lethal dose value, it was secondary source information and only endpoints were available form various references.

- In the Schafer and Bowles (1985) paper, two acute oral toxicity tests were also conducted on deer mice.

A reliability rating of 4 was assigned to this paper, according to the criteria of Klimisch, 1997 as details of the toxic effects were not reported other than the lethal dose value, it was secondary source information, the preferred species was not used and only endpoints were available form various references.

- For the ATSDR (2005) report a reliability rating of 4 was assigned to this study, according to the criteria of Klimisch, 1997 as this information is from a secondary source.

In an acute toxicity study in the Golden Syrian hamster the test material was found to have a 2 week LD50 of 149.6 mg/kg/day for males and 172 mg/kg/day in females.

- Supporting information is available from a Tributyltin chloride material safety data sheet, Atofina Chemicals Inc. (2001).

A reliability rating of 4 was assigned to this study, according to the criteria of Klimisch, 1997 as this information is from a secondary source.

In an acute toxicity study in the rat the test material was found to have an LD50 of between 122 and 160 mg/kg.

- Supporting information is available from a Tributyltin chloride material safety data sheet, Atofina Chemicals Inc. (2001).

A reliability rating of 4 was assigned to this study, according to the criteria of Klimisch, 1997 as this information is from a secondary source.

In an acute toxicity study in the mouse the test material was found to have an LD50 of between 60 and 117 mg/kg.

- In the Schweinfurth (1985) paper, the LD50 for tributyltin chloride in the rat is given as 122 mg/kg. This can be interpreted as toxic according to EU criteria.

A reliability rating of 4 was assigned to this paper, according to the criteria of Klimisch, 1997 as this information is from a secondary source.

Only supporting studies are available for Inhalation toxicity:

- In the Sachsse (1974) paper, the LC50 of TK 11388 determined after an observation period of 7 days in rats of both sexes, exposed to the substance for four hours is smaller than 78 mg/m³, air.

A reliability rating of 3 was assigned to this paper, according to the criteria of Klimisch, 1997 as although the methods look similar to OECD 403 there are severe deviations: Used as supporting study only due to restrictions. Only 2 concentrations used. LC50 is a less than value due to deaths.

- Supporting information is available from a Tributyltin chloride material safety data sheet, Atofina Chemicals Inc. (2001).

A reliability rating of 4 was assigned to this study, according to the criteria of Klimisch, 1997 as this information is from a secondary source.

The 1 hour LC50 for TBTC on rats via inhalation is 0.2-0.4 mg/L.

Only a supporting study is available for Dermal toxicity:

- Supporting information is available from a Tributyltin chloride material safety data sheet, Atofina Chemicals Inc. (2001).

A reliability rating of 4 was assigned to this study, according to the criteria of Klimisch, 1997 as this information is from a secondary source.

The LD50 for tributyltin chloride applied dermally to rabbits is given as 500 mg/kg.

Justification for classification or non-classification

Based on the available data for acute toxicity: oral this sustance is considered to be toxic if swallowed and would be classified as 'Acute Tox. 3' according to Regulation (EC) no 1272/2008.

It should also be noted that although there are no reliable data available for inhalation and dermal studies as these endpoints are not needed for intermediate substances, the results would suggest that classification for these endpoints should be considered.

With this in mind the following classifications will also apply:

In the Sachsse (1974) paper all the animals died after exposure to 78 mg/m³ tributyltin chloride, and so the LC50 was determined to be < 78 mg/m³. Although this paper was assigned a reliability rating of 3 due to deviations and the < LC50 value, a worst case scenario should therefore be used for classification purposes and so tributyltin chloride will be classified as Acute Tox. 1; H330: Fatal if inhaled, according to Regulation (EC) no 1272/2008.

It should also be noted that some impurities present at >1 % would impart the above inhalation classification.

According to the official classification below, tributyltin compounds are classified as Acute Tox. 4; H312: Harmful in contact with skin, according to Regulation (EC) no 1272/2008. Although the supporting dermal study cannot officially be used for classification purposes, as the information was obtained from a secodary source, it should be considered when determining the classification, and on this basis a precautionary approach has been taken which would increase the CLP classification to Acute tox. 3; H311: Toxic in contact with skin.

It should be noted that the official classification for tributyltin compounds according to regulation (EC) No 1272/2008, Annex VI, Table 3.1 is as follows:

(EC) No 1272/2008:

Classification		Labelling
Hazard class and category code(s)	Hazard statement code(s)	Pictogram signal word code(s)	Hazard statement code(s)
Acute Tox. 3*	H301		H301
Acute Tox. 4*	H312		H312
STOT RE 1	H372**	GHS06	H372**
Eye Irrit. 2	H319	GHS08	H319
Skin Irrit. 2	H315	GHS09	H315
Aquatic Acute 1	H400	Dgr	H410
Aquatic Chronic 1	H410

Specific concentration limits and M factors
Concentration	Classification
*	-
STOT RE 1; H372	C ≥ 1 %
STOT RE 2; H373	0,25 % ≤ C < 1 %
Skin Irrit. 2; C ≥ 1 %	-
Eye Irrit. 2; C ≥ 1 %	-
M = 10	-