Ammonium mercaptoacetate

Endpoint summary

Description of key information

Ammonium thioglycolate 71% (ATG 71) is considered to be slightly irritating to the skin and the eyes. 

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

Study period:

4 Mar 2003 - 9 Mar 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

French Republic, Prime Minister, Interministerial Group on Chemicals (GIPC)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: CEGAV, Saint Mars d'Egrenne, France
- Age at study initiation: 2 to 4 months
- Weight at study initiation: 2.4 ± 0.1 kg
- Housing: individually in polystyrene cage (48.2 x 58 x 36.5 cm)
- Diet (e.g. ad libitum): 110 pelleted diet (SAFE, Villemoisson, Epinay-sur-Orge, France) ad libitum
- Water (e.g. ad libitum): filtered drinking water ad libitum
- Acclimation period:at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 ± 3
- Humidity (%): 30 to 70
- Air changes (per hr): approximately 12
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): 71.5 % active substance

Duration of treatment / exposure:

3 min, 4 h

Observation period:

The skin was examined approximately 1 hour, 24, 48 and 72 hours after removal of the dressing.
Since there was persistent irritation reactions at 72 hours, the observation period was extended up to their complete reversibility (day 6).

Number of animals:

3

Irritation parameter:

erythema score

Remarks:

3-minute exposure

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: one animal

Irritation parameter:

edema score

Remarks:

3-minute exposure

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: one animal

Irritation parameter:

erythema score

Remarks:

4 -hour exposure

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: day 6

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Interpretation of results:

GHS criteria not met

Conclusions:

The test item ammonium thioglycolate 71% is slightly irritating when applied topically to rabbits.

Classification: not irritating

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

Study period:

11 Mar 2003 - 16 Mar 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

French Republic, Prime Minister, Interministerial Group on Chemicals (GIPC)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: CEGAV (Saint Mars d'Egrenne, France)
- Age at study initiation:  2-4 months
- Weight at study initiation: 2.7+/-0.2 kg
- Housing: individually in polystyrene cage (48.2 x 58 x 36.5 cm)
- Diet (e.g. ad libitum): 110 pelleted diet (SAFE, Villemoisson, Epinay sur Orge, France) ad  libitum
- Water (e.g. ad libitum): filtered drinking water ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18+/-3
- Humidity (%): 30-70
- Air changes (per hr): approx. 12
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 mL
- Concentration (if solution): 71.5% active substance

Duration of treatment / exposure:

continuous

Observation period (in vivo):

1, 24, 48, 72 h

Number of animals or in vitro replicates:

3

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

2

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

2

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

2

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.7

Max. score:

3

Reversibility:

fully reversible within: 72 h

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 72 h

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 72 h

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 72 h

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 72 h

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 72 h

(For details on results refer to attached background material)

Very slight to moderate conjunctival reactions, including a very slight or slight chemosis (grade 1 or 2), a very slight to moderate redness of the conjunctiva (grades 1 to 3) and a clear to whitish purulent discharge, were observed in all animals, from day 1 up to day 3. No other ocular reactions were noted during the study.

Mean scores calculated for each animal over 24, 48 and 72 hours were 0.7, 0.7 and 0.7 for chemosis, 0.7, 1.0 and 1.0 for redness of the conjunctiva, 0.0, 0.0 and 0.0 for iris lesions and 0.0, 0.0 and 0.0 for corneal opacity.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item ammonium thioglycolate 71% is slightly irritant when administrated by ocular route to rabbits.
The criteria for classification as an eye irritant are not met.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The skin irritation potential of ammonium thioglycolate (71% solution) and sodium thioglycolate (98% pure) was evaluated in studies performed according to the OECD guideline 404 (Klein, 2003c and 2003d). Because irritant effects were anticipated, a single albino rabbit was tested first before the other two animals were used. The test material (0.5 ml or 0.5 g) was applied to the shaved, intact skin on one flank for 3 min and for 4 h on the other flank in the first animal. The sites were semi-occluded.

The test materials were non-irritating in the first animal, so it was applied to a single flank in the other two rabbits for 4 h (the other flank served as a control). The animals were examined for signs of erythema, eschar, and edema and skin reactions were measured 1, 24, 48, and 72 h after termination of exposure. Both substances induced a slight irritation.

The skin irritation potential of 71% ammonium thioglycolate was also evaluated in a former study performed according to the US EPA guideline 16 CFR 1500.41. 0.5 ml test material was applied to each of two sites, one on abraded skin, and the other site on intact skin of each of 6 rabbit. The test sites were then immediately occluded for a 24-hour exposure period. At the end of 24 hours, the plastic wrappings and patches were removed. The skin sites were then individually examined and scored separately for both erythema and edema using the Draize method. After 72 hours the sites were examined and rescored.

Three of the six rabbits died during the test. The mean erythema scores over 24 and 72 hours for each surviving animal were 3.0, 3.0 and 3.0 for both the intact and abraded skin. The edema scores were 2.5, 3.0 and 2.5 for the intact skin and 2.5, 2.5 and 2.5 for the abraded skin (Griffiths and Koschier, 1979b). Under the condition of a 24-hour occlusive exposure, 71% ammonium thioglycolate was severely irritating to the skin.

Skin irritation has also been reported in humans in the context of skin sensitisation tests. Refer to Section 7.10.

The eye irritation potential of ammonium thioglycolate (71% solution) and sodium thioglycolate (98% pure) has been investigated in rabbits in studies compliant with the OECD guidelines 405 (Klein, 2003e and 2003f). A volume of 0.1 ml of ammonium thioglycolate or 100 mg of sodium thioglycolate was instilled into the conjunctival sac of one eye of the 3 test animals. The eyes were not rinsed after administration of the test item. The other eyes served as controls. The eye irritation reactions were scored approximately 1 hour, 24, 48 and 72 hours (both salts) and up to 8 days (sodium salt only) after the instillation. Both compounds induced a slight irritation.

At the 72-hour scoring, all scores were 0.0 for the 3 rabbits treated with ammonium thioglycolate. With sodium thioglycolate, all scores were 0.0 at 72 hours for rabbits 1 and 2 and on day 8 for rabbit 3. Both compounds are considered as slightly irritating.

The eye irritation potential of ammonium thioglycolate (71% solution) has also been investigated in a study compliant with the US EPA guideline 16 CFR 1500.42 (Griffiths and Koschier, 1979c). A volume of 0.1 ml of ammonium thioglycolate was instilled into the conjunctival sac of one eye of the 6 test animals. The eyes were not rinsed after administration. The other eyes served as controls. The eye irritation reactions were scored approximately 1 hour, 24, 48 and 72 hours and 7 days after the instillation. Ammonium thioglycolate induce a mild irritation, mean enanthema (redness), chemosis, corneal opacity and iritis scores over 24, 48 and 72 hours were 2.6, 0.0, 0.0 and 0.0, respectively. On day 7 redness score was zero.

Justification for classification or non-classification

Justification for selection of skin irritation / corrosion endpoint:
In contrast to Griffiths et al. the study conducted by Klein is a GLP and guideline study.

Justification for selection of eye irritation endpoint:
In contrast to Griffiths et al. the study conducted by Klein is a GLP and guideline study.