Sodium O-isobutyl dithiocarbonate

Endpoint summary

Description of key information

-The acute eye irritation study indicates that SIBX (the result was read across from sodium ethyl xanthate) as a powder caused mild to moderate irritation, while it is not an irritant in the diluted form (10% solution).
-The results of the study (Hazleton Laboratories 1951) indicate that SIBX (the result was read across from sodium ethyl xanthate) is a moderate irritant to the skin while the 10% solution is non irritating to the skin. 
-The acute dermal irritation of isobutanol was examined in a 4 -hour exposure . Minor to moderate erythema and edema on 6 of 6 rabbits, superficial necrosis on 2, ecchymoses on 1, fissuring on 1, desquamation on 4 and alopecia on 2 from 0.5 ml. Two rabbits had a normal appearance within 14 days; minor irritation persisted on the remaining 4 rabbits.
Based on the descriptions of the lesions it is considered that SIBX  is classifiable as an moderately irritant according to EU criteria
-The results of the study (Dow Chemical Company 1976) indicate that SIBX (the result was read across from potassium amyl xanthate) has an adverse effect at concentration of 252mg/m3 on the central nervous system and liver in mice, the liver and kidneys in rats and the liver in dogs. There were no treatment-related changes in the haematological or urinalysis values in any of the animals. No signs of irritation of respiratory tract and Nasal effects were observe

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4470 (Acute Dermal Irritation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Male and female New Zealand White rabbits were received from Hazleton Research Products, Inc. (Denver, PA). The strain and species were selected because of their availability and existing historical data. Rabbits were ordered to be between 2.0 and 2.3 kg (designated by the supplier to be approximately 12 to 14 weeks of age). The females were nulliparous and nonpregnant.

Periodically, a Clinical Veterinarian examined rabbits for any signs of health deficiencies. Within 1 or 2 days of receipt, all animals were assigned a unique number which was marked on the animal cage card. The rabbit number was also marked in indelible ink on 1 ear at the time of dosing.

The rabbits were housed individually in cages with wire floors (approximately 61.0 x 46.0 x 36.0 cm.). DACBQ (Deotized Animal Cage Board; Shepherd Specialty Papers, Inc.) was placed under each cage and changed regularly. An automatic timer was set to provide fluorescent lighting for a 12-hour photoperiod (approximately 0500 to 1700 hours for the light phase). Temperature and relative humidity were recorded (Cole-Parmer Hygrothermograph Seven-Day Continuous Recorder, Model No. 8368-00, Cole-Parmer Instrument Co., Chicago, IL). Temperature was routinely maintained at 61-70°F during the test period; relative humidity was routinely maintained at 40-70%. Any minor exceptions to these specified ranges were noted in the raw data.
Tap water (Municipal Authority of Westmoreland County, Greensburg, PA) was available ad libitum (except during dosing) and was delivered by an automatic watering system with demand control valves mounted on each rack. Water analyses were provided by the supplier, Halliburton NUS Environmental Laboratories, Materials Engineering & Testing Company, and Lancaster Laboratories, Inc. at regular intervals. EPA standards for maximum levels of contaminants were not exceeded. As available, water analysis reports were reviewed by the Study Director. AGWAYe PROLABe Animal Diet High Fiber Rabbit (Agway Inc.) was available ad libitum except during the actual dosing period. No analyses of chemical composition and possible contaminants of the feed were conducted by the supplier.

Animal Acclimation
The animals were acclimated for at least 5 days before dosing. Detailed clinical observations were conducted twice, at the time of receipt and during animal identification and/or dosing. In addition, rabbits were examined and weighed twice prior to dosing. Cage-side observations and mortality checks were conducted at least once daily. Animals considered unacceptable for the study, based on the clinical signs or body weights (rabbits), were rejected for use on this study.
Study Organization
The animals were weighed and inspected for health on the day of the test. Only those exhibiting a healthy state were used. Healthy animals appeared alert, active and well groomed, with no evidence of discharge, diarrhea, breathing difficulties or locomotor abnormalities. A BRRC veterinarian was available for consultation regarding any animal health concerns. Animals were randomly assigned to cages and were designated for dosing according to need and availability.

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5 ml

Duration of treatment / exposure:

4 hours

Observation period:

Readings were made at 1, 24, 48 and 72 hours and at 7 and 14 days, after the end of the contact period.

Number of animals:

3 males and 3 females

Details on study design:

The fur was removed from the dorsal area of the trunk of each rabbit using veterinary clippers a few days before dosing and the dose area was trimmed carefully (avoiding skin abrasion), as necessary, up to the day before application of the test substance. A 1-inch square gauze patch was placed over 1 intact (nonabraded) site/rabbit and secured by adhesive tape. A volume of 0.5 ml was then applied under the patch. Polyethylene sheeting was placed loosely around the trunk and secured. The animal was placed in a restraining device for the 4-hour contact period after which the coverings and as much excess test substance as possible were removed.

The test substance was applied to each of 6 rabbits (3 males, 3 females). Readings were made at 1, 24, 48 and 72 hours and at 7 and 14 days, after the end of the contact period according to the method of Draize, 1959. All rabbits were sacrificed at 14 days (ear vein injection using Euthanasia-6 Solution).

Reference
Draize, J. H. (1959). The Appraisal of Chemicals in Foods, Drugs and Cosmetics. Tbe Association of Food and Drug Officials of the United States.

Irritation parameter:

erythema score

Basis:

mean

Remarks:

6

Time point:

24/48/72 h

Score:

1.2

Max. score:

2

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: Maximum score observed. One animal had a score of 1 on day 14.

Irritation parameter:

edema score

Basis:

mean

Remarks:

6

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: Maximum score observed. One animal had a score of 1 on day 14.

Irritant / corrosive response data:

Application of 0.5 ml of isobutanol to covered rabbit skin for a 4-hour contact period produced minor to moderate erythema and edema on 6 of 6 rabbits within 1 day. (Maximum score noted on any animal for erythema or edema was 2). One rabbit had a light brown discoloration on the dose site at 1 hour. Superficial necrosis developed on this animal by 1 day; another rabbit had superficial necrosis at 7 days. Ecchymoses were apparent on 1 animal within 1 day. At 7 days, fissuring was observed on 1 animal. Four rabbits had desquamation at this time. By 14 days, alopecia was observed on 2 rabbits. Erythema and edema subsided on 5 of 6 rabbits within 14 days; minor erythema and edema persisted on 1 rabbit. Two rabbits had a normal appearance at this time.

Other effects:

No additional information available.

Interpretation of results:

other: moderately irritating

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Minor to moderate erythema and edema on 6 of 6 rabbits, superficial necrosis on 2, ecchymoses on 1, fissuring on 1, desquamation on 4 and alopecia on 2 from 0.5 ml. Two rabbits had a normal appearance within 14 days; minor irritation persisted on the remaining 4 rabbits.

Executive summary:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate .

The acute dermal irritation of isobutanol was examined in a 4 -hour exposure. Minor to moderate erythema and edema on 6 of 6 rabbits, superficial necrosis on 2, ecchymoses on 1, fissuring on 1, desquamation on 4 and alopecia on 2 from 0.5 ml. Two rabbits had a normal appearance within 14 days; minor irritation persisted on the remaining 4 rabbits.

Reference 2

Endpoint:

skin irritation / corrosion, other

Remarks:

This study was conducted in 1951 and was repeated later in the same year. The initial study was performed to assess dermal irritation but deaths during the study led to further studies.

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

SIBX are related compound to SEX

Qualifier:

no guideline followed

Principles of method if other than guideline:

This study was conducted in 1951 and was repeated later in the same year. Exposure in both studies was for 18 hrs and was not according to the OECD Guidelines for acute dermal irritation (4 hrs) or for dermal toxicity (24 hrs). The initial study was performed to assess dermal irritation but deaths during the study led to further studies. Sodium ethyl xanthate was administered by occlusive application to the shaved abdomen of the rabbits either as 1.0 ml/kg of a 10% aqueous solution or as 1 gm/kg of the 100% dry material in a paste formed with water. The animals were observed for 12 days.

GLP compliance:

not specified

Species:

rabbit

Strain:

not specified

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

other: 10% aqueous solution and unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

Sodium ethyl xanthate was administered by occlusive application to the shaved abdomen of the rabbits either as 1.0 ml/kg of a 10% aqueous solution or as 1 gm/kg of the 100% dry material in a paste formed with water. The animals were observed for 12 days.

Observation period:

The animals were observed for 12 days.

Number of animals:

12

Details on study design:

This study was conducted in 1951 and was repeated later in the same year. Exposure in both studies was for 18 hrs and was not according to the OECD Guidelines for acute dermal irritation (4 hrs)or for dermal toxicity (24 hrs).The initial study was performed to assess dermal irritation but deaths during the study led to further studies. Sodium ethyl xanthate was administered by occlusive application to the shaved abdomen of the rabbits either as 1.0 ml/kg of a 10% aqueous solution or as 1 gm/kg of the 100% dry material in a paste formed with water. The animals were observed for 12 days.

Irritation parameter:

other: oedema and pigmentation of the skin.

Basis:

mean

Time point:

other: 24 hrs

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: Application of 1 gm/kg of sodium ethyl xanthate in the form of a paste resulted in the death of ten out of twelve animals within 24 hrs. The surviving animals had moderate irritation with oedema and pigmentation of the skin.

Irritant / corrosive response data:

Application of 1 gm/kg of sodium ethyl xanthate in the form of a paste resulted in the death of ten out of twelve animals within 24 hrs. The surviving animals developed irritant effects including oedema and pigmentation of the skin.
Clinical Observations :surviving animal had moderate irritation with oedema and pigmentation of the skin.

Other effects:

Moderate amount of peritoneal fluid, visceral organs were normal.
Haemorrhagic lungs and peritoneal and pleural fluid. Other changes were markedly cyanotic ears (2/5), haemorrhagic conditions (2/5) and evidence of diarrhoea (3/5).
The liver appeared darkand mottled and the kidneys showed spotty haemorrhages

The dermal irritation/toxicity study in rabbits indicates that sodium ethyl xanthate powder

is a moderate irritant while the10% solution is non irritating to the skin.

Results of the dermal application studies are summarised in Table 4.

Table 4:	Effects of sodium ethyl xanthate following dermal application
Animals	Dose	Clinical Observations	Gross pathology
3 rabbits	1 ml/kg, as 10% solution	No skin irritation.	No substance related changes.
3 rabbits	1 gm/kg, as a paste	2/3 died; surviving animal had moderate irritation with oedema and pigmentation of the skin.	Moderate amount of peritoneal fluid, visceral organs were normal.
5 male rabbits	1 gm/kg, as a paste	5/5 died following overnight exposure; oedemaof the skin with pigmentation.	Haemorrhagic lungs andperitoneal and pleural fluid. Other changes were markedly cyanotic ears (2/5), haemorrhagic conditions (2/5) and evidence of diarrhoea (3/5).
1 male rabbit	1 gm/kg, as a more liquid paste than above	Moderate oedema and pigmentation of the skin.	No substance related changes.
3 rabbits	1 gm/kg as a paste	All 3 animals died within24 hrs; retropulsion,salivation, loss of rightingreflex and haemorrhagicand oedematous areas of the skin were noted.	The liver appeared dark and mottled and the kidneysshowed spotty haemorrhages.

 

 

Interpretation of results:

moderately irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the study, application of 10% solution of sodium ethyl xanthate (pH 10.5 to 11) for 18 hrs did not cause skin irritation in rabbits. Similar application of 1 gm/kg of sodium ethyl xanthate in the form of a paste resulted in the death of ten out of twelve animals within 24 hrs. The surviving animals developed irritant effects including oedema and pigmentation of the skin. The sulphide odour noted during the study suggests that decomposition of sodium ethyl xanthate occurred.

Executive summary:

The results of the study (Hazleton Laboratories 1951) indicate that SIBX (the result was read across from sodium ethyl xanthate) is a moderate irritant while the 10% solution is non irritating to the skin.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

SIBX is related compound to SEX

Qualifier:

no guideline followed

Principles of method if other than guideline:

Method: other: The study was done in 1951 using sodium ethyl xanthate as a 10% solution at pH 10.5 to 11 and as a fine powder. Two groups of three albino rabbits each were used in this study.
A 0.05 ml aliquot of 10% aqueous solution of sodium ethyl xanthate was instilled into the conjunctival sacs of the left eyes of albino rabbits of one group. The eyes were held closed for one minute, observed immediately for reaction 1 hr and 4 hrs later and then daily for 9 days.

GLP compliance:

not specified

Species:

rabbit

Strain:

other: albino rabbits

Details on test animals or tissues and environmental conditions:

TEST ANIMALS: Rabbit
- Strain: albino rabbits
- Sex: Not reported
- Source: Not reported
- Age: Not reported
- Weight at study initiation: Not reported
- Number of animals: 6

Vehicle:

other: 10% aqueous solution and unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

-10% aqueous solution of sodium ethyl xanthate
-30 mg powder of sodium ethyl xanthate

Duration of treatment / exposure:

A 0.05 ml aliquot of 10% aqueous solution of sodium ethyl xanthate was instilled into the conjunctival sacs of the left eyes of albino rabbits of one group. The eyes were held closed for one minute, observed immediately for reaction 1 hr and 4 hrs later and then daily for 9 days.
30 mg of sodium ethyl xanthate powder was applied to the conjunctival sacs of the second group of rabbits.

Observation period (in vivo):

9 days

Number of animals or in vitro replicates:

6

Details on study design:

-A 0.05 ml aliquot of 10% aqueous solution of sodium ethyl xanthate was instilled into the conjunctival sacs of the left eyes of albino rabbits of one group. The eyes were held closed for one minute, observed immediately for reaction 1 hr and 4 hrs later and then daily for 9 days.
-Approximately 30 mg of sodium ethyl xanthate powder was applied to the conjunctival sacs of the second group of rabbits. All three animals showed immediate marked irritation, scrambling, excitement and evidence of pain. There was lacrimation in one animal and phonation in another. Moderate irritation and oedema of the lids was observed in all the animals at the end of 1 hr. The same observations were noted at 4 hrs with one animal showing exudate. Mild irritation was seen after 24 hrs and two rabbits appeared normal after three days. One rabbit showed slight irritation until day 5. There were no signs of opacity or necrosis. The symptoms seen in the animals could be due to the physical irritation caused by solid particles in the eye. The animals were sacrificed on day 9 when no gross pathology was observed at autopsy.

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24 hrs

Reversibility:

fully reversible

Remarks:

4 days

Remarks on result:

other: Powder is a moderate irritant to rabbit eyes while the 10% aqueous solution is mildly irritating .The eye effects produced by the powder were reversible, persisting for 24 hrs in all the animals with the effects lasting for up to 4 days in one animal.

Irritant / corrosive response data:

DESCRIPTION OF LESIONS:
-Mild irritation was observed immediately after instillation of 10% aqueous solution of sodium ethyl xanthate
There were no signs of oedema or necrosis. Autopsy on day 9 did not reveal any gross pathology.
 -Moderate irritation to rabbit eyes was evident after instillation of 30 mg of sodium ethyl xanthate powder to the conjunctival sacs.
All three animals showed immediate marked irritation, scrambling, excitement and evidence of pain. There was lacrimation in one animal and phonation in another. Moderate irritation and oedema of the lids was observed in all the animals at the end of 1 hr. The same observations were noted at 4 hrs with one animal showing exudate. Mild irritation was seen after 24 hrs and two rabbits appeared normal after three days. One rabbit showed slight irritation until day 5. There were no signs of opacity or necrosis. The symptoms seen in the animals could be due to the physical irritation caused by solid particles in the eye.The animals were sacrificed on day 9 when no gross pathology was observed at autopsy.

REVERSIBILITY:
-Mild irritation was evident after instillation of 10% aqueous solution but the eyes appeared normal one hour later. One animal showed slight irritation at 4 hrs but was normal on the second day.
-Moderate irritation to rabbit eyes was evident after instillation of 30 mg of sodium ethyl xanthate powder.The eye effects produced by the powder were reversible, persisting for 24 hrs in all the animals with the effects lasting for up to 4 days in one animal.

The results of this study indicate that the powder is a moderate irritant to rabbit eyes while the 10% aqueous solution of sodium ethyl xanthate is mildly irritating. The irritant effects of the solution disappeared 1 hr after instillation. The eye effects produced by the powder were reversible, persisting for 24 hrs in all the animals with the effects lasting for up to 4 days in one animal.

DESCRIPTION OF LESIONS:

-Mild irritation was observed immediately after instillation of 10% aqueous solution of sodium ethyl xanthate

There were no signs of oedema or necrosis. Autopsy on day 9 did not reveal any gross pathology.

 -Moderate irritation to rabbit eyes was evident after instillation of 30 mg of sodium ethyl xanthate powder to the conjunctival sacs.

All three animals showed immediate marked irritation, scrambling, excitement and evidence of pain. There was lacrimation in one animal and phonation in another. Moderate irritation and oedema of the lids was observed in all the animals at the end of 1 hr. The same observations were noted at 4 hrs with one animal showing exudate. Mild irritation was seen after 24 hrs and two rabbits appeared normal after three days. One rabbit showed slight irritation until day 5. There were no signs of opacity or necrosis. The symptoms seen in the animals could be due to the physical irritation caused by solid particles in the eye.The animals were sacrificed on day 9 when no gross pathology was observed at autopsy.

REVERSIBILITY:

-Mild irritation was evident after instillation of 10% aqueous solution but the eyes appeared normal one hour later. One animal showed slight irritation at 4 hrs but was normal on the second day.

-Moderate irritation to rabbit eyes was evident after instillation of 30 mg of sodium ethyl xanthate powder.The eye effects produced by the powder were reversible, persisting for 24 hrs in all the animals with the effects lasting for up to 4 days in one animal.

The results of this study indicate that the powder is a moderate irritant to rabbit eyes while the 10% aqueous solution of sodium ethyl xanthate is mildly irritating. The irritant effects of the solution disappeared 1 hr after instillation. The eye effects produced by the powder were reversible, persisting for 24 hrs in all the animals with the effects lasting for up to 4 days in one animal.

Interpretation of results:

other: moderately irritating

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Based on the descriptions of the lesions it is considered that SIBX (the result was read across from sodium ethyl xanthate) is classifiable as an moderately irritant according to EU criteria
Classification: moderately irritating

Executive summary:

The results of this study indicate that the powder is a moderate irritant to rabbit eyes while the 10% aqueous solution of SIBX (the result was read across from sodium ethyl xanthate) is mildly irritating.The irritant effects of the solution disappeared 1 hr after instillation. The eye effects produced by the powder were reversible, persisting for 24 hrs in all the animals with the effects lasting for up to 4 days in one animal.

Reference 2

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4500 (Acute Eye Irritation)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Male and female New Zealand White rabbits were received from Hazleton Research Products, Inc. (Denver, PA). The strain and species were selected because of their availability and existing historical data. Rabbits were ordered to be between 2.0 and 2.3 kg (designated by the supplier to be approximately 12 to 14 weeks of age). The females were nulliparous and nonpregnant.

Periodically, a Clinical Veterinarian examined rabbits for any signs of health deficiencies. Within 1 or 2 days of receipt, all animals were assigned a unique number which was marked on the animal cage card. The rabbit number was also marked in indelible ink on 1 ear at the time of dosing.

The rabbits were housed individually in cages with wire floors (approximately 61.0 x 46.0 x 36.0 cm.). DACBQ (Deotized Animal Cage Board; Shepherd Specialty Papers, Inc.) was placed under each cage and changed regularly. An automatic timer was set to provide fluorescent lighting for a 12-hour photoperiod (approximately 0500 to 1700 hours for the light phase). Temperature and relative humidity were recorded (Cole-Parmer Hygrothermograph Seven-Day Continuous Recorder, Model No. 8368-00, Cole-Parmer Instrument Co., Chicago, IL). Temperature was routinely maintained at 61-70°F during the test period; relative humidity was routinely maintained at 40-70%. Any minor exceptions to these specified ranges were noted in the raw data.
Tap water (Municipal Authority of Westmoreland County, Greensburg, PA) was available ad libitum (except during dosing) and was delivered by an automatic watering system with demand control valves mounted on each rack. Water analyses were provided by the supplier, Halliburton NUS Environmental Laboratories, Materials Engineering & Testing Company, and Lancaster Laboratories, Inc. at regular intervals. EPA standards for maximum levels of contaminants were not exceeded. As available, water analysis reports were reviewed by the Study Director. AGWAYe PROLABe Animal Diet High Fiber Rabbit (Agway Inc.) was available ad libitum except during the actual dosing period. No analyses of chemical composition and possible contaminants of the feed were conducted by the supplier.

Animal Acclimation
The animals were acclimated for at least 5 days before dosing. Detailed clinical observations were conducted twice, at the time of receipt and during animal identification and/or dosing. In addition, rabbits were examined and weighed twice prior to dosing. Cage-side observations and mortality checks were conducted at least once daily. Animals considered unacceptable for the study, based on the clinical signs or body weights (rabbits), were rejected for use on this study.
Study Organization
The animals were weighed and inspected for health on the day of the test. Only those exhibiting a healthy state were used. Healthy animals appeared alert, active and well groomed, with no evidence of discharge, diarrhea, breathing difficulties or locomotor abnormalities. A BRRC veterinarian was available for consultation regarding any animal health concerns. Animals were randomly assigned to cages and were designated for dosing according to need and availability.

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

Initial study
0.1 ml

Follow up study
0.01 ml

Duration of treatment / exposure:

24 hours

Observation period (in vivo):

Initial study
1, 24, 48, 52.5 hours and at 7, 9, 14, 15 and 21 days following instillation.
Follow up study
1, 24, 48 and 72 hours and at 7, 10 and 14 days

Number of animals or in vitro replicates:

Initial study
1 male and 1 female

Follow up study
2 males and 2 females

Details on study design:

Both eyes of each rabbit to be dosed were examined, using fluorescein stain, within 24 hours before application. If any preexisting eye injury was
apparent, the rabbit was rejected for use in the test. A volume of 0.1 ml of test substance was placed into the conjunctival sac of 1 eye/rabbit. The other eye of each animal served as the control.

A total of 2 rabbits (1 male and 1 female) were first dosed because of the potential for the test substance to produce severe ocular irritation. Eye examinations were made at 1, 24, 48, 52.5 hours and at 7, 9, 14, 15 and 21 days following instillation. Readings were not made at 72 hours because of a lost workday resulting from severe weather conditions. However, in anticipation of the lost workday, an additional reading was made in the afternoon of the second day following dose administration. Fluorescein staining was performed at 1 day and each subsequent examination day. Grading and scoring were performed by the system of Draize (1959). All rabbits were sacrificed by ear vein injection (Euthanasia-6 Solution) at 21 days.

Because severe ocular irritancy resulted from a dose of 0.1 ml, an additional 4 rabbits (2 males, 2 females) were dosed with 0.01 ml for comparison. These rabbits were dosed as described above except the dose was applied directly onto the cornea. Eye examinations were made at 1, 24, 48 and 72 hours and at 7, 10 and 14 days (Draize, 1959). All 4 animals were sacrificed at 14 days (ear vein injection using Euthanasia-6 Solution).

Reference
Draize, J. H. (1959). The Appraisal of Chemicals in Foods, Drugs and Cosmetics. Tbe Association of Food and Drug Officials of the United States.

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

2

Time point:

24/48/72 h

Score:

1

Max. score:

1

Reversibility:

fully reversible within: 21 days

Irritation parameter:

iris score

Basis:

mean

Remarks:

2

Time point:

24/48/72 h

Score:

0.7

Max. score:

1

Reversibility:

fully reversible within: 21 days

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

2

Time point:

24/48/72 h

Score:

2.3

Max. score:

3

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: Minor conjunctival redness was still evident at 21 days.

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

2

Time point:

24/48/72 h

Score:

1.8

Max. score:

3

Reversibility:

fully reversible within: 21 days

Irritant / corrosive response data:

A volume of 0.1 ml of test substance instilled into rabbit eyes produced minor to moderate corneal injury in 2 of 2 rabbits. Iritis and severe conjunctival irritation were also apparent in both rabbits. One rabbit developed severe conjunctival swelling within 1 hour. At 24 hours, both rabbits had hemorrhages of the nictitating membrane. One animal also had a purulent ocular discharge. Within 7 days, corneal vascularization developed on 1 rabbit. Except for alopecia, 1 rabbit had a normal ocular appearance at 9 through 15 days. Minor conjunctival redness was again evident in this animal at 21 days. Minor conjunctival redness persisted in the other rabbit at this time.

Following the application of 0.01 ml of isobutanol onto 4 rabbit eyes, minor corneal injury was observed in 2. Iritis and moderate to severe conjunctival irritation were apparent in all 4 rabbit eyes. At 48 and 72 hours, 2 rabbits had hemorrhages of the nictitating membrane and/or sclera. One rabbit had a normal ocular appearance at 72 hours and another 2 rabbit eyes were healed at 7 days. All 4 rabbits had a normal ocular appearance by 14 days.

Other effects:

Both animals dosed with 0.1 ml had alopecia of the periocular area (with a small scab on 1) by 9 days.

Interpretation of results:

other: irritating

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Instillation of 0.1 ml of isobutanol into rabbit eyes produced severe ocular irritation. Minor conjunctival redness was still evident at 21 days. MinorModerate to severe irritation was produced from the application of 0.01 ml.

Executive summary:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate .

The eye irritation potential of isobutanol was examined in rabbits. Instillation of 0.1 ml of isobutanol into rabbit eyes produced severe ocular irritation. Minor conjunctival redness was still evident at 21 days. Moderate to severe irritation was produced from the application of 0.01 ml.

Reference 3

Endpoint:

eye irritation, other

Remarks:

Due to the severity of the response only one animal was exposed to the test substance and the study was terminated on humane grounds 24 h after instillation.

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPP 81-4 (Acute Eye Irritation)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

- Source: A. Smith, England
- Age at study initiation: ca. 12 weeks
- Weight at study initiation: 2.6 kg

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.1 mL

Duration of treatment / exposure:

n.a.

Observation period (in vivo):

24 h

Number of animals or in vitro replicates:

1

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

other: 24 h

Score:

3

Reversibility:

not reversible

Irritation parameter:

iris score

Basis:

animal #1

Time point:

other: 24 h

Score:

2

Reversibility:

not reversible

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

other: 24 h

Score:

3

Reversibility:

not reversible

Remarks on result:

other: Necrosis and partial destruction of nictitating membrane.

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: 24 h

Score:

4

Reversibility:

not reversible

Other effects:

Due to the severity of the response only one animal was exposed to the test substance and the study was terminated on humane grounds 24 h after instillation.

Interpretation of results:

other: irritating

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Instillation of 0.1 ml of ziram into rabbit eyes produced severe ocular irritation.
Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

Eye irritation

The study (Hazleton Laboratories, 1951) was done in 1951 using sodium ethyl xanthate as a 10% solution at pH 10.5to 11 and as a fine powder. Two groups of three albino rabbits each were used in thisstudy.

A 0.05 ml aliquot of 10% aqueous solution of sodium ethyl xanthate was instilled into the conjunctival sacs of the left eyes of albino rabbits of one group. The eyes wereheld closed for one minute, observed immediately for reaction 1 hr and 4 hrs laterand then daily for 9 days.

Mild irritation was observed immediately after instillation but the eyes appeared normal one hour later.One animal showed slightirritation at 4 hrs but was normal on the second day. There were no signs of oedema ornecrosis.Autopsy on day 9 did not reveal any gross pathology.

 

Approximately 30 mg of sodium ethyl xanthate powder was applied to theconjunctival sacs of the second group of rabbits. All three animals showed immediate marked irritation, scrambling, excitement and evidence of pain. There waslacrimation in one animal and phonation in another. Moderate irritation andoedema of the lids was observed in all the animals at the end of 1 hr. The sameobservations were noted at 4 hrs with one animal showing exudate. Mild irritationwas seen after 24 hrs and two rabbits appeared normal after three days. One rabbitshowed slight irritation until day 5. There were no signs of opacity or necrosis. Thesymptoms seen in the animals could be due to the physical irritation caused by solidparticles in the eye. The animals were sacrificed on day 9 when no gross pathologywas observed at autopsy.

The results of this study indicate that the powder is a moderate irritant to rabbit eyes while the 10% aqueous solution of sodium ethyl xanthate is mildly irritating.The irritant effects of the solution disappeared 1 hr after instillation. The eye effects produced by the powder were reversible, persisting for 24 hrs in all the animals with the effects lasting for up to 4 days in one animal.

Based on the descriptions of the lesions it is considered that SIBX (the result was read across from sodium ethyl xanthate) is classifiable as an moderately irritant according to EU criteria.

Skin irritation

-The results of thestudy (Hazleton Laboratories 1951) indicate that SIBX (the result was read across from sodium ethyl xanthate) is a moderate irritant while the 10% solution is non irritating to the skin.

Under the conditions of the study, application of 10% solution of sodium ethyl xanthate (pH 10.5 to 11) for 18 hrs did not cause skin irritation in rabbits. Similar application of 1 gm/kg of sodium ethyl xanthate in the form of a paste resulted in the death of ten out of twelve animals within 24 hrs. The surviving animals developed irritant effects including oedema and pigmentation of the skin. The sulphide odour noted during the study suggests that decomposition of sodium ethyl xanthate occurred.

-2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

The acute dermal irritation of isobutanol was examined in a 4 -hour exposure (Christopher, S.M.1993). Minor to moderate erythema and edema on 6 of 6 rabbits, superficial necrosis on 2, ecchymoses on 1, fissuring on 1, desquamation on 4 and alopecia on 2 from 0.5 ml. Two rabbits had a normal appearance within 14 days; minor irritation persisted on the remaining 4 rabbits.

Based on the descriptions of the lesions it is considered that SIBX is classifiable as an moderately irritant according to EU criteria

Respiratory irritation.

In the 30-day study, three groups of animals, each consisting of 10 male Swiss-Webster mice, 10 male Sprague-Dawley rats, 4 male New Zealand White rabbitsand 2 male beagle dogs were exposed to either filtered room air or to concentrationsof 100 or 800 mg/m3 of potassium amyl xanthate. Whole body exposure was for 6 hrsdaily, 5 days a week for a total of 20 exposures in 1 month.

Ten mice of the 800 mg/m3group died along with 5/6 replacement mice.

The animals were observed during the exposures and body weights were recordedthree times a week throughout the experiment. Body weight data, organ to bodyweight ratios and clinical laboratory parameters were analysed statistically usinganalysis of variance and Dunnett’s test.

Most of the mice died when exposed to 800 mg/m3. Five of the 16 mice that diedshowed convulsions and hyperactivity prior to death.

The results of the study (Dow Chemical Company 1976) indicate that SIBX (the result was read across from potassium amyl xanthate) has an adverseeffect at concentration of 252mg/m3on the central nervous system and liver in mice, the liver and kidneys in ratsand the liver in dogs. There were no treatment-related changes in the haematological or urinalysis values in any of the animals.No signs of irritation of respiratory tract and Nasal effects were observed.

Effects on skin irritation/corrosion: moderately irritating

Effects on eye irritation: moderately irritating

Justification for classification or non-classification

Based on the hazard assessment of SIBX in section 2.1 and 2.2. in IUCLID 6, available data for the substance and following the “Guidance on Information Requirement and Chemical Safety Assessment R.8. Characterisation of dose [concentration]- response for human health” andaccording to the criteria described in Directive 67/548 and in the CLP Regulation:

Directive 67/548

Skin Corrosivity C R35 Causes severe burns R34 Causes burns Skin Irritation Xi R38 Irritating to skin R43 May cause sensitization by skin contact Eye Irritation (Ocular Lesions) Xi R36 Irritating to eyes R37 irritating to respiratory system R41 Risk of serious damage to eyes

CLP

Skin Corrosivity  H314 Skin Corr 1A Causes severe skin burns and eye damage H314 Skin Corr 1B Causes severe skin burns and eye damage Skin Irritation  H315 Skin Irrit. 2 Causes skin irritation H317 Skin Sens. 1 May cause an allergic skin reaction Eye Irritation (Ocular Lesions) Xi H319 Eye Irrit. 2 Causes serious eye irritation H318 Eye Dam. 1 Causes serious eye damage H335 STOT SE 3 May cause respiratory irritation

 

 

It is concluded that the substance SIBX meet the criteria to be classified for human health hazards for Dermal-local effect:  R36 Irritating to eyes,  H319 Eye Irrit. 2 Causes serious eye irritation

 

It is concluded that the substance SIBX meet the criteria to be classified for human health hazards for Dermal-local effect R38 Irritating to skin, H315 Skin Irrit. 2 Causes skin irritation

 

It is concluded that the substance SIBX does not meet the criteria to be classified for human health hazards for respiratory irritation