Potassium isopentyl dithiocarbonate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was considered not reliable since the documentation of the study was insufficient for assessment. Especially, no details on the test substance composition was provided. Read-across justification: Target substance belongs into the group of substances called xanthates. The xanthates are generally prepared from the reaction of the alkoxide, which reacts with carbon disulphide to give the xanthate. These substances contain common functional group which is dithiocarbonate (-OCSS-). Though they are structural analogues with the target substance. All these analogue substances are also used in similar use application as water solutions. All xanthates decompose in the presence of water. In neutral to alkaline media, they will release carbon disulphide, particular alcohol(s) and carbonates and dithiocarbonates. Carbon disulphide is the major and the most volatile and the most hazardous decomposition product of xanthates. It is also more toxic to human health than the target substance. As the xanthates can be considered as a group of substances which have structural similarity and similar behaviour in contact with water and in the physiological processes, their irritation as well as acute and systemic adverse effects to human health are similar. Therefore, and in order to avoid the unnecessary animal testing, the read-across data from the analogue xanthates is used to evaluate the irritation, and short term and/or long-term toxicological effects of the target substance. As the target substance is an unstable compound, the apparent toxicity reflects to the toxicity of the degradation products. The selection of the most critical degradation products for the hazard assessment are based on the known decomposition reaction of the target substance and based on the physicochemical properties and toxicological properties of the degradation products. The adverse effects through inhalation route are not relevant for the substance itself, which is a solid non-volatile pellet form substance. However, the most serious human health hazards are related to CS2 released from the target substance. Therefore, the formation of carbon disulphide by decomposition is the driving force for human health hazard assessment via inhalation and taken into account in DNEL derivation and in the exposure assessment of the target substance.

Data source

Reference

Reference Type:

secondary source

Title:

Sodium Ethyl Xanthate - Priority Exiting Chemical No. 5

Author:

National Industrial Chemicals Notification and Assessment Scheme (NICNAS)

Year:

1995

Bibliographic source:

Australian Government Publishing Service Canberra

Materials and methods

Principles of method if other than guideline:

Sodium ethyl xanthate was administered by occlusive application to the shaved abdomen of the rabbits either as 1 g/kg bw of the 100% dry material in a paste formed with water. The animals were observed for 12 days.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium O-ethyl dithiocarbonate

EC Number:

205-440-9

EC Name:

Sodium O-ethyl dithiocarbonate

Cas Number:

140-90-9

IUPAC Name:

sodium O-ethyl dithiocarbonate

Test material form:

semi-solid (amorphous): gel

Remarks:

migrated information: paste

Test animals

Species:

rabbit

Administration / exposure

Type of coverage:

occlusive

Duration of exposure:

18 hrs

Doses:

1 000 mg/kg bw

No. of animals per sex per dose:

Three rabbits

Results and discussion

Effect levels

Sex:

not specified

Dose descriptor:

LD50

Effect level:

< 1 000 mg/kg bw

Based on:

test mat.

Clinical signs:

other: Surviving animal had moderate irritation with oedema and pigmentation of the skin.

Gross pathology:

Moderate amount of peritoneal fluid, visceral organs were normal.

Applicant's summary and conclusion

Interpretation of results:

Toxicity Category IV

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

Rabbit were exposed to sodium ethyl xanthate for 18 hours. The LD50 value was concluded to be < 1 000 mg/kg bw.

Executive summary:

This study was conducted for the analogue substance. The study was considered not reliable since the documentation of the study was insufficient for assessment. Especially, no details on the test substance was provided. Thus, this study is used as a weight of evidence in the hazard assessment.