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Administrative data

Description of key information

Oral:
There are two studies available for acute oral toxicity for the target substance.
The oral LD50 (mouse) is 470 mg/kg bw
The oral LD50 (rat) is 765 mg/kg bw
Inhalation:
No study available
Dermal:
There is no valid data available for acute dermal toxicity for the target substance.
The dermal LD50 (rat; male, female) for sodium ethyl xanthate, the analogue substance, is < 1 000 mg/kg bw.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records
Reference
Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: This study was regarded not reliable since the documentation is insufficient for assesment.
Reference:
Composition 0
Principles of method if other than guideline:
The test substance was administered orally in rats. The animals were observed for two days for clinical signs and mortality.
GLP compliance:
no
Test material information:
Composition 1
Species:
rat
Strain:
not specified
Sex:
male
Control animals:
not specified
Sex:
male
Dose descriptor:
LD50
Effect level:
765 mg/kg bw
Based on:
test mat.
Clinical signs:
Symptoms varied from anxiety to narcosis. No details on clinical signs reported. In the surviving animals the adverse effects disappeared on the 3rd - 5th day after test substance administration.
Interpretation of results:
Toxicity Category IV
Remarks:
Migrated information Criteria used for interpretation of results: expert judgment
Conclusions:
The acute oral toxicity of the test substance was evaluted in male rats. The LD50 value was concluded to be 765 mg/kg bw.
Executive summary:

This study was regarded not reliable since the documentation is not sufficicient for assessment. The study result is used as weight of evidence in CSA.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
470 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Acute toxicity: via dermal route

Link to relevant study records
Reference
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.
Reference:
Composition 0
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 information:
Composition 1
Species:
rabbit
Type of coverage:
occlusive
Duration of exposure:
18 hrs
Doses:
1 000 mg/kg bw
No. of animals per sex per dose:
Three rabbits
Sex:
not specified
Dose descriptor:
LD50
Effect level:
< 1 000 mg/kg bw
Based on:
test mat.
Clinical signs:
Surviving animal had moderate irritation with oedema and pigmentation of the skin.
Gross pathology:
Moderate amount of peritoneal fluid, visceral organs were normal.
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.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
1 000 mg/kg bw

Additional information

Acute toxicity oral

Weight of evidence approach is used to assess the acute oral toxicity of potassium isoamyl xanthate based on the data from the substance itself and from the analogue substance (potassium butyl xanthate). Read-across justification is presented in Annex I of the CSR.

There are two low quality studies available to evaluate the acute oral toxicity of potassium isoamyl xanthate (Trofimovich, E. M. 1976). The acute toxicity of the substance was investigated in mice and in rats after intragastric administration. The LD50 (mouse) was calculated to be 470 mg/kg and the LD50 (rat) 765 mg/kg bw. Death of animals was observed during first two days after test substance administration. Immediately after administration of the test substance increased motor activity was observed, later animals were narcotic. The surviving animals recovered within 3-5 days after the test substance administration. The study was considered not reliable since the documentation of the study was insufficient for assessment. Especially, no details on the test substance composition and possible impurities in the test substance were provided.

There is available acute oral toxicity study conducted for the analogue substance, potassium butyl xanthate.

In this low quality study by Babaian, E. A. (1963) the test substance was administered orally in rats. Oral administration of potassium butyl xanthate to rats produced increased motor activity, cyanosis, irritability, increased respiration and convulsions with death occurring 1 to 2 hours after administration. The LD50 was 411 mg/kg. Autopsy showed perivascular and pericellular oedema, multiple haemorrhages in the lungs, perivascular subarachnoid haemorrhages and acute swelling of the cells of the cortex, subcortical ganglia and the brain stem. Fatty dystrophy of the liver and protein dystrophy of the twisted canaliculi of the kidneys were observed.

As a conclusion, the oral LD50-values from potassium amyl xanthate and from the analogue substance are considered reliable enough for C&L purposes. These results indicate this substance is be classified to hazard category Acute Tox 4 in accordance with the criteria set out in the CLP Regulation 1272/2008 and Directive 67/548/EEC.

Acute toxicity dermal

There is no valid data available for acute dermal toxicity for the target substance. Based on the pH of 25-% water solution of the substance (pH 11.8) study is not needed as the substance should be classified as corrosive to skin and eyes. Because of this hazard classification the PPEs are worn to protect skin and eye contact and the exposure is unlikely.

However, one dermal toxicity study is conducted for the read-across substance (sodium ethyl xanthate).The read-across justification is presented in the Annex I of this CSR. Rabbits were exposed to the test substance for 18 hours. Based on the study results the LD50 value < 1 000 mg/kg was determined. This would indicate classification of sodium ethyl xanthate for category 3 for acute dermal toxicity. This classification is assigned also for potassium isoamyl xanthate.


Justification for selection of acute toxicity – oral endpoint
The study is conducted for the target substance.

Justification for selection of acute toxicity – inhalation endpoint
Not likely exposure route for the parent substance which is solid. The hazards of the most critical decomposition product (CS2) are taken into account in HA and CSA as it is released from the target substance in use applications from xanthate water solutions.

Justification for selection of acute toxicity – dermal endpoint
No study available for the target substance. This study was conducted for analogue substance, sodium ethyl xanthate.

Justification for classification or non-classification

The available data for potassium isoamyl xanthate indicate low potential for acute toxicity. Based on the LD50 values of the substance and the analogue substance, potassium isoamyl xanthate has to be classified to hazard classes Acute Tox 4 H302 (oral) and Acute Tox 3 H311 (dermal) according to CLP Regulation 1272/2008 and Xn; R21/22 according to Directive 67/548/EEC.