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Administrative data

Description of key information

Oral Key Study: Rush (1993): LD50 = 204.5 mg/kg using male and female rats
Oral Key Study: Cooper and Terrell (1979): LD50 = 160 mg/kg in female rats
Inhaltion Key Study: Sachsse and Ullmann (1977): 4 hour LC50 = 115 mg/m³ air (analytical) using male and female rats
Dermal Key Study: Rush (1993): 24 hour LD50 = 404 mg/kg bw using male and female rabbits

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
160 mg/kg bw
Quality of whole database:
Two high quality studies were available for evaluation, both showing that the material is toxic via the oral route. A number of supporting literature studies were also available, which could only be assigned a Klimisch score of 4 due to the lack of detail (with the exception of one study which was assigned a reliability score of 3 due to the method of dosing). The quality of the database was therefore high.

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LC50
115 mg/m³
Quality of whole database:
A number of Klimisch 2 studies were available to address this endpoint. Often the duration of exposure differed from the standard 4 hours required in the OECD guideline. The LC50 value from Sachsse and Ullmann (1977) was chosen ahead of that from Sternet and Grawhit (1976) on a worst case basis. The overall quality of the database was considered to be good.

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
404 mg/kg bw
Quality of whole database:
Only one full study report was available, along with two Klimisch 4 literature sources with limited detail. The limited dosing level in the Barnes and Stoner (1958) study meant that it was not suitable for use in evaluating the toxicity of the substance. The key study was the only available data suitable to be carried forward for risk assessment and classification and labelling purposes, the quality of the study was high (Klimisch 1)

Additional information

Oral

There were two obvious studies to be considered as key, Rush (1993) and Cooper and Terrell (1979) study. Both studies were well reported and conducted to a method similar to OECD 401. The LD50 value from both studies were similar. Cooper and Terrell gave the slightly lower combined LD50 value of 175 mg/kg bw (Lowest LD 50 =160 mg/kg in females), as opposed to 204.5 mg/kg bw reported in Rush. Rush was conducted to GLP standard and was not performed with such a high vehicle content, although it does not explicitly state what the solvent is in the 50% solution, it can probably be assumed to be water. Cooper and Terrell used a 1% corn oil vehicle solution, which dosed a high volume of vehicle into the rat. Although no deaths were observed in the control group dose with only vehicle, there were some short term clinical signs observed that were attributed to the effect of such a large dosage. Cooper and Terrell had a higher purity of dimethyltin dichloride at 98.7 %, as opposed to only 84.8 % in Rush. There are merits to both studies and, as such, both are considered key for this endpoint. On a worst case basis, the lower LD50 value of 175 mg/kg bw is considered as the key value for the chemical safety assessment.

Inhalation

Two reliable 4 hour studies were available for this endpoint. Sachsse and Ullmann (1977) gave an LC50 of 115 mg/m³ and Sterner & Grawhit (1976) gave an LC50 of 139 µl/l. Taking into account the density of dimethyltin dichloride (1.4 g/mL), the latter would convert to an LC50 of 194.6 mg/L which gives 194600 mg/m³. On a worst case basis, and the fact the concentration was determined analytically, Sachsse and Ullmann (1977) was selected as key. The result of this study shows that dimethyltin dichloride is fatal if inhaled.

Dermal

Only one full study report was available for this endpoint. The study was well reported and in line with the OECD 403 and EU B3 test guidelines and therefore considered suitable to be the key study for this endpoint. The result of this study shows that dimethyltin dichloride is toxic via the dermal route.


Justification for selection of acute toxicity – oral endpoint
The LD50 from the Cooper and Terrell (1979) study was selected on a worst case basis (Lowest LD50 value). The purity of dimethyltin dichloride was 98.7% administered at 100, 150, 200, 250 and 300 mg/kg bw . This is a reliable study conducted in a method equivalent to OECD 401.

Justification for selection of acute toxicity – inhalation endpoint
This study was chosen on the basis that it is a well reported study with an exposure duration of 4 hours and conducted in-line with the principles of the guideline OECD 403. As there were a number of studies of equal quality, this study was selected to be representative of a worst case scenario.

Justification for selection of acute toxicity – dermal endpoint
The key study was selected as it was the only full study report available that was sufficient for risk assessment and classification and labelling purposes.

Justification for classification or non-classification

In accordance with the criteria outlined in Regulation (EC) No. 1272/2008 (CLP), the substance meets the following criteria for classification for acute toxicity:

Oral: 'Acute Tox. 3' with the associated hazard phrase H301 'Toxic if swallowed'

Dermal: 'Acute Tox. 3' with the associated hazard phrase H311 'Toxic in contact with skin'

Inhalation: 'Acute Tox. 2' with the associated hazard phrase H330 'Fatal if inhaled'

In accordance with the criteria outlined in Directive 64/548/EEC (Dangerous Substances Directive), the substance meets the following criteria for classification for acute toxicity.

Oral: 'Toxic' with the associated risk phrase R25 'Toxic if swallowed'

Dermal: 'Harmful' with the associated risk phrase R21 'Harmful in contact with skin'

Inhalation: 'Very toxic' with the associated risk phrase R26 'Very toxic by inhalation'