Tetrakis(diethyldithiocarbamato-S,S')tellurium

Endpoint summary

Description of key information

The available skin and eye irritation studies with rabbits indicate that the test substance is not irritating/corrosive to skin and eye.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of the test item (as cited in study report): Tellurium diethyldithiocarbamate
- Batch No.: MT-5D 494
- Appearance: Yellow, powder

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Froxfield Rabbits, Petersfield, Hampshire, England
- Weight at study initiation: 2.0-3.0 kg
- Age at study initiation: 9-13 weeks
- Housing: The rabbits were individually housed in metal cages with perforated floors.
- Diet: SDS, Standard Rabbit Diet (ad libitum)
- Water: tap water (ad libitum)

ENVIRONMENT
- Temperature: 19 °C
- Humidity: 30-70%
- Air changes (per hr): 19
- Photoperiod (hrs dark / hrs light): 12 / 12

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

physiological saline

Controls:

no

Amount / concentration applied:

0.5 g

Duration of treatment / exposure:

24 hours

Observation period:

Examination of the treated skin sites was made approximately 30 minutes and 24, 48, 72 and 96 hours after removal of the patches.

Number of animals:

Six female rabbits

Details on study design:

Approximately 24 hours prior to application of the test substance, hair was removed with electric clippers from the dorso-lumbar region of each rabbit exposing an area of skin approximately 10 cm square. Immediately prior to application of the test substance, two areas of skin approximately 2.5 cm square on the right side of the spine were abraded using the tip of a scalpel blade to make minor incisions through the stratum corneum. These were not deep enough to disturb the dermis or cause bleeding. Two similar sites on the left side remained intact. A 0.5 g amount of the test substance was applied under a 2.5 cm square gauze pad moistened with 0.5 ml saline to two intact and two abraded skin sites on each animal. The treatment sites were occluded with "Elastoplast" elastic adhesive dressing for approximately 24 hours. "Elizabethan collars" were placed on each animal in order to prevent the animal from disturbing the test sites. The animals were not restrained during thee exposure period and were returned to their cages. At the end of the exposure period the semi-occlusive dressing and gauze pads were removed and the treatment sites wiped to remove any residual test substance.

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

None of the animals showed any observable response to treatment throughout the 5-day observation period.

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of the test item (as cited in study report): Tellurium diethyldithiocarbamate
- Batch No.: MT-5D 494
- Appearance: Yellow, powder

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Morton Commercial Rabbits, Stansted, Essex, England.
- Weight at study initiation: 2.1-2.7 kg
- Age at study initiation: 9-12 weeks
- Housing: The rabbits were individually housed in metal cages with perforated floors.
- Diet: SDS, Standard Rabbit Diet (ad libitum)
- Water: tap water (ad libitum)

ENVIRONMENT
- Temperature: 19 °C
- Humidity: 30-70%
- Air changes (per hr): 19
- Photoperiod (hrs dark / hrs light): 12 / 12

Vehicle:

unchanged (no vehicle)

Controls:

other: The contralateral eye remained untreated and served as a control

Amount / concentration applied:

60 mg

Duration of treatment / exposure:

In three animals, the test substance was rinsed after 20-30 seconds. In the other six animals, the eyes remained unrinsed.

Observation period (in vivo):

1 hour and 1, 2, 3, 4 and 7 days after instillation.

Number of animals or in vitro replicates:

9 animals (1 male, 8 females)

Details on study design:

Both eyes of each animal were examined 24 hours prior to instillation of the test substance using fluorescein stain to ensure that there was no pre-existing corneal damage or conjuctival inflammation. Just prior to instillation of the test substance, the eyes were examined without using fluorescein stain. A 60 mg amount of tellurium diethyildithiocarbamate (0.1 mL in volume) was placed into the lower everted lid of one eye of each animal. 1 hour and 1, 2, 3, 4 and 7 days after instillation, the animals were examined. Observation of the eyes was aided by the use of a handheld torch. Fluorescein stain was used to detect and evaluate corneal damage from one day after instillation. Grading and scoring of the ocular lesions were performed according to Draize.

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.67

Max. score:

4

Reversibility:

fully reversible within: 96 hours

Remarks on result:

other: unrinsed eyes

Irritation parameter:

cornea opacity score

Basis:

animal: #2, #3, #4, #6

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: unrinsed eyes

Irritation parameter:

cornea opacity score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: unrinsed eyes

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Remarks on result:

other: unrinsed eyes

Irritation parameter:

conjunctivae score

Basis:

animal: #1, #2, #4, #5, #6

Time point:

24/48/72 h

Score:

0

Max. score:

3

Remarks on result:

other: unrinsed eyes

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.67

Max. score:

3

Reversibility:

fully reversible within: 72 hours

Remarks on result:

other: unrinsed eyes

Irritation parameter:

chemosis score

Basis:

animal: #1, #2, #4, #5, #6

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: unrinsed eyes

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: unrinsed eyes

Irritant / corrosive response data:

In animals with eyes rinsed after 20-30 seconds no corneal damage or iridial inflammation was observed. Mild conjunctival inflammation was seen in all three animals at the one hour reading only.

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin

In a pre-GLP study similar to OECD TG 404, skin irritation was assessed with six New-Zealand rabbits. The intact skin (clipped) of the animals was exposed to 0.5 g of the test substance on an area of 2.5 cm² under a gauze pad (semi-occlusive) moistened with 0.5 ml saline for 24 hours. Examination was made approximately 30 minutes and 24, 48, 72, 96 hours after exposure.

Based on the average erythema and oedema scores, the substance is considered to be not irritating to skin.

In a pre-GLP study similar to OECD TG 404, skin irritation was assessed with twelve New-Zealand rabbits (six on intact skin and six on abraded skin). Animals were exposed to 0.5 g of the test substance on an area of ca. 2.5 cm² for 24 hours. Examinations were made 24 and 72 hours after the start of the exposure. Based on the results, the substance is considered to be not irritating to skin.

Eye

In a pre-GLP acute toxicity study similar to OECD 405, eye irritation was assessed with six New Zealand rabbits. Animals were exposed to 60 mg (0.1 ml) of the test substance. Eyelids were held together for one second before releasing. The eye was not rinsed afterwards. The untreated eye served as a control. Eyes were examined 1 hour and 1, 2, 3, 4 and 7 days after instillation and scored according to the Draize scale. Two animals gave a positive response (corneal opacities). Transient mild conjunctival reactions only were seen in all six animals. No iridial inflammation or irritation was observed. All eyes were normal one to four days after instillation. Under the conditions of the test, the test substance was not considered irritating to eyes.

In a pre-GLP acute toxicity study similar to OECD 405, eye irritation was assessed with six New Zealand rabbits. Animals were exposed to 100 mg of the test substance. Eyelids were held together for one second before releasing. The eyes were not rinsed afterwards. The untreated eye served as a control. Eyes were examined 1 hour and 1, 2, 3, 4 and 7 days after instillation and scored according to the Draize scale. Slight conjunctivitis was observed 24 hours after instillation in three animals. After 48 hours, all eye lesions recovered completely. Under the conditions of the test, the test substance was not considered irritating to eyes.

Justification for classification or non-classification

Based on the results of the skin and eye irritation tests the substance does not have to be classified for skin or eye irritation according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.