Glycollic acid

Endpoint summary

Description of key information

Skin irritation potential for glycolic acid was assessed using in vivo methods.  The material is a dermal irritant but effects are concentration and pH dependent and under extreme conditions glycolic acid may be corrosive to skin.  Glycolic acid presents a serious risk of damage to eyes and may cause ocular corrosion.

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

- Source: Hare Marland, Hewitt, New Jersey.
- Weight at study initiation: 2316-2620 grams.
- Housing: Received in suspended, stainless steel, wire-mesh cages. Then placed in 8"x18" stock fitted with rubber sheeting.
- Diet: Approximately 125 grams offered per day of Purina Certified High Fiber Rabbit Chow #5325.
- Water: Ad libitum.
- Acclimation period: Approximately 2 weeks.
-Age: Young.
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/- 2.
- Humidity (%): 50 +/- 10.
- Photoperiod (hrs dark / hrs light): 12 hours light, 12 hours dark.

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g.
- Concentration: 99% Glycolic Acid.

Duration of treatment / exposure:

3 minutes, 1 hour and 4 hours

Observation period:

Observations noted after each exposure time and for up to 14 days after treatment

Number of animals:

6 Females.

Details on study design:

TEST SITE
- Area of exposure: Back (from scapular to lumbar.)
- % coverage: not specified
- Type of wrap if used: 2-inch gauze held in place with non-irritating tape and covered with rubber sheeting during the
exposure period.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes, with Ivory soap after evaluations

SCORING SYSTEM: Draize

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Reversibility:

other: time basis: 3 minutes

Remarks on result:

probability of weak irritation

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Reversibility:

other: time basis 3 minutes

Remarks on result:

probability of weak irritation

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Reversibility:

other: time basis 3 minutes

Remarks on result:

probability of weak irritation

Irritation parameter:

erythema score

Basis:

animal #4

Time point:

24/48/72 h

Score:

1

Reversibility:

other: time basis 3 minutes

Remarks on result:

probability of weak irritation

Irritation parameter:

erythema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 3 minutes

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 3 minutes

Remarks on result:

probability of mild irritation

Irritation parameter:

edema score

Basis:

animal: 1 - 6

Remarks:

No edema observed at 3 minutes in any animal.

Time point:

24/48/72 h

Score:

0

Reversibility:

other: time basis 3 minutes

Remarks on result:

no indication of irritation

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 1 h

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 1 h

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 1 h

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #4

Time point:

24/48/72 h

Score:

3

Reversibility:

other: time basis 1 h

Remarks on result:

probability of moderate irritation

Irritation parameter:

erythema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

3

Reversibility:

other: time basis 1 h

Remarks on result:

probability of moderate irritation

Irritation parameter:

erythema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

4

Reversibility:

other: time basis 1 h

Remarks on result:

probability of severe irritation

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Reversibility:

other: time basis 1 h

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Reversibility:

other: time basis 1 h

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Reversibility:

other: time basis 1 h

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

animal #4

Time point:

24/48/72 h

Score:

1

Reversibility:

other: time basis 1 h

Remarks on result:

probability of weak irritation

Irritation parameter:

edema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

1

Reversibility:

other: time basis 1 h

Remarks on result:

probability of weak irritation

Irritation parameter:

edema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 1 h

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 4 h

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 4 h

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 4 h

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #4

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 4 h

Remarks on result:

probability of mild irritation

Irritation parameter:

erythema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

3

Reversibility:

other: time basis 4 h

Remarks on result:

probability of moderate irritation

Irritation parameter:

erythema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

3

Reversibility:

other: time basis 4 h

Remarks on result:

probability of moderate irritation

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Reversibility:

other: time basis 4 h

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Reversibility:

other: time basis 4 h

Remarks on result:

probability of weak irritation

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 4 h

Remarks on result:

probability of mild irritation

Irritation parameter:

edema score

Basis:

animal #4

Time point:

24/48/72 h

Score:

2

Reversibility:

other: time basis 4 h

Remarks on result:

probability of mild irritation

Irritation parameter:

edema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

3

Reversibility:

other: time basis 4 h

Remarks on result:

probability of moderate irritation

Irritation parameter:

edema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

3

Reversibility:

other: time basis 4 h

Remarks on result:

probability of moderate irritation

Irritant / corrosive response data:

The test substance produced slight to mild erythema, but no edema in the treated rabbits following the 3-minute exposure period.
Necrosis was observed in 3 test sites after 1-hour exposure period. Mild to severe erythema and no to mild edema were also observed.
Necrosis was also observed in 4 test sites that were designated for the 4-hour exposure period but evaluated after a 1-hour exposure period. Mild to moderate erythema and no or moderate edema were observed in these test sites.

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Conclusions:

Under the conditions of this study, glycolic acid was a skin corrosive agent when applied to the shaved, intact skin of rabbits.

Executive summary:

99% glycolic acid was evaluated in six female rabbits. The material was placed on two test sites of each rabbit for three minutes or one hour. The test material produced slight or mild erythema, but no edema in the treated rabbits after the three-minute exposure. Necrosis was seen in three test sites after a one-hour exposure; mild to severe erythema and no to mild edema were also seen. Necrosis was also seen in four test sites that were designated for a four-hour exposure but evaluated after an one hour exposure; mild to moderate erythema and no to moderate edema were seen in these test sites. Thus 99% glycolic acid is a skin corrosive when applied to shaved, intact rabbit skin. Under the conditions of this test, Glycolic acid is considered to be corrosive to the skin.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Link to relevant study records

Reference

Reference 1

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:

other: Study conducted and reported prior to introduction of test guidelines. Non-GLP.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

study conducted prior to guidelines

Deviations:

yes

Remarks:

; in contrast to current guidelines much of the standard method detail is omitted. Use of the Draize assessment for ocular scoring is omitted. Insufficient detail to determine average scores or reactions at 24 to 72 hours post-instillation

GLP compliance:

no

Remarks:

study conducted prior to GLP introduction

Species:

rabbit

Strain:

other: Albino

Details on test animals or tissues and environmental conditions:

No further information.

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.1 mL of test material was dosed into the right conjunctival sac of each rabbit.
- Amount(s) applied (volume or weight with unit):0.10 mL .
- Concentration (if solution): Undiluted.

Duration of treatment / exposure:

After 20 seconds, the treated eye of one rabbit was washed with tap water for one minute. The treated eye of the other rabbit was not washed.

Observation period (in vivo):

Assessments at 1 and 4 hours; and 1, 2, 3, 7, and 14 days.
14 days post exposure observation

Number of animals or in vitro replicates:

2

Details on study design:

Examination: 1 and 4 hours, 1, 2, 3, 7and 14 days after instillation.
Observations of cornea, iris and conjunctiva were made with a hand-slit lamp; Fluor-i-strip® stain and a biomicroscope were used in examinations after the day of treatment.
REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes, one animal's treated eye with tap water for 1 minute. Other animal's treated eye not washed.
- Time after start of exposure: 20 seconds.
SCORING SYSTEM: No data or observations.
TOOL USED TO ASSESS SCORE: Hand-slit lamp at 1 and 4 hours; and 1, 2, 3, 7, and 14 days. Fluor-i-strip stain and a biomicroscope used after day of treatment.

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

animals #1,#2

Time point:

24/48/72 h

Score:

>= 3

Max. score:

3

Reversibility:

not reversible

Remarks:

7 days

Remarks on result:

other: Moderate to total opacity

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

animals #1,#2

Time point:

24/48/72 h

Score:

>= 3

Max. score:

3

Reversibility:

not reversible

Remarks:

14 d

Remarks on result:

other: Eye shrunken and cornea looked soft

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

animals #1,#2

Time point:

24/48/72 h

Score:

>= 3

Max. score:

3

Reversibility:

not reversible

Remarks:

7 d

Remarks on result:

probability of severe irritation

Remarks:

corrosive in 7 days in unwashed eye

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

animals #1,#2

Time point:

24/48/72 h

Score:

>= 3

Max. score:

3

Reversibility:

not reversible

Remarks:

14 d

Remarks on result:

probability of severe irritation

Remarks:

corrosive in 3-14 days in washed eye

Irritation parameter:

iris score

Basis:

mean

Remarks:

animals #1,#2

Time point:

24/48/72 h

Score:

>= 1.5

Max. score:

1.5

Reversibility:

not reversible

Remarks:

24 h

Remarks on result:

other: Moderate congestion of vessels with slight pupil constriction

Irritation parameter:

iris score

Basis:

mean

Remarks:

animals #1,#2

Time point:

24/48/72 h

Score:

>= 1.5

Max. score:

1.5

Reversibility:

not reversible

Remarks:

7 d

Remarks on result:

other: Severe gross destruction of iris

Irritation parameter:

iris score

Basis:

mean

Remarks:

animals #1,#2

Time point:

24/48/72 h

Score:

>= 1.5

Max. score:

1.5

Reversibility:

not reversible

Remarks:

14 d

Remarks on result:

other: Lens appeared to be displaced with risk of rupturing the soft cornea. No reaction to light.

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

animal #1,#2

Time point:

24/48/72 h

Score:

>= 0

Max. score:

0

Reversibility:

not specified

Remarks on result:

not measured/tested

Irritant / corrosive response data:

Instillation of glycolic acid to the eyes of two rabbits resulted severe, irreversible ocular damage.
The results indicate that glycolic acid is corrosive to rabbit eyes.

Eye not washed:
Cornea - Moderate to slight opacity at 1 hour. Moderate to total opacity (opalescent) from 4 hours to 7 days. Corneal swelling moderate to severe at 1-3 days. Thin spots at 7 days. Eye shrunken and cornea looked soft at 14 days.
Iris - Moderate congestion of vessels with slight pupil constriction at 1 hour to 1 day. Severe gross destruction of iris at 2-7 days. Lens appeared to be displaced with risk of rupturing the soft cornea at 14 days. No reaction to light.
Conjunctiva - Blanched with necrotic areas at 1 hour to 2 days. Hemorrhages at 3 days. Corrosive at 7 days. Mild swelling at 1 hour, becoming moderate to severe at 4 hours to 1 day. Severe at 2 to 7 days. Eyelids becoming hardened at 7 days. Copious, Hemastix positive discharge at 1 hour to 7 days, becoming purulent at 2 to 7 days.

Washed:
Cornea - Slight to total opacity at 1 hour to 14 days. Area (~1/4 of cornea) very dense and red (could not see individual blood vessels) at 7 days. Center of cornea almost clear and bulging with vascularization and adhesions of sclera to cornea at all edges at 14 days.
Iris - Moderate congestion of vessels with slight pupil constriction at 1-4 hours. Moderate congestion with remarkable flare 1-3 days. Severe possible destruction of iris at 7 days. No reaction to light at 14 days.
Conjunctiva - Blanched with necrotic areas at 1 hour to 2 days. Corrosive at 3 to 14 days. Moderate to mild swelling at 1 hour to 1 day. Severe swelling at 2 to 14 days. Eyelid becoming hardened at 3 days. Copious, Hemastix positive discharge at 1 hour to 7 days, becoming purulent at 2 days.

Glycolic acid was corrosive to rabbit eyes. Ocular effects were severe and irreversible. By 14 days the test was terminated because one treated eye had become very small and had no reaction to light. The other treated eye did react to light, but the cornea looked like it could rupture.

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

Glycolic acid is classified as an eye irritant. Although study conducted and reported prior to introduction of test guidelines the information provided is sufficient to conclude the corrosive nature of the material and to justify the classification and labelling of glycolic acid. Glycolic acid is corrosive to rabbit eyes at the concentration and dose (0.10 mL) used in this test. Ocular effects were severe and irreversible. By 14 days the test was terminated because one treated eye had become very small and had no reaction to light. The other treated eye did react to light, but the cornea looked like it could rupture. This acid behaves in much the same way as strong mineral acids in contact with ocular tissue.

Executive summary:

Two albino rabbits were dosed by instillation of 0.1 mL of glycolic acid into the right conjunctival sac of one eye. The test substance was left ‘in situ’ in the first rabbit; the eye of the second rabbit was rinsed for one minute with tap water 20 seconds after instillation. Ocular irritation was evaluated after 1 and 4 hours, 1, 2, 3, 7 and 14 days post-instillation. Effects were seen in the cornea, iris and conjuctiva one hour after dosing in both rabbits. By 14 days, observation was terminated because one treated (unwashed) eye, which had become very small, had no reaction to light. The other eye (washed) reacted to light although the cornea appeared as if it would rupture. Glycolic acid is corrosive to rabbit eyes.

 

Study conducted and reported prior to introduction of test guidelines. In principle the investigations meet the objectives of current guidelines but much of the standard method detail is omitted. Use of the Draize assessment for ocular scoring is omitted. There is insufficient detail to determine average scores or reactions at 24 to 72 hours post-instillation.

 

However, the information provided is sufficient to conclude the corrosive nature of the material and to justify the classification and labelling of glycolic acid. The results indicate that glycolic acid is corrosive to rabbit eyes.

Reference 2

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

raised by Hoechst AG; weight 2.5 - 3.1 kg;
room temperature: 20+-2°C, relative humidity: 55+-10 %

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.1 mL, 1 eye treated

Duration of treatment / exposure:

24 h

Observation period (in vivo):

21 d

Number of animals or in vitro replicates:

3

Details on study design:

only animals with intact cornea used
second, untreated eyes used as controls

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

, animals #1, #2, #3

Time point:

24/48/72 h

Score:

2.4

Max. score:

3

Irritation parameter:

iris score

Basis:

mean

Remarks:

, animals #1, #2, #3

Time point:

24/48/72 h

Score:

0.8

Max. score:

1

Irritation parameter:

conjunctivae score

Remarks:

(reddening)

Basis:

mean

Remarks:

, animals #1, #2, #3

Time point:

24/48/72 h

Score:

2.2

Max. score:

3

Irritation parameter:

conjunctivae score

Remarks:

(swelling)

Basis:

mean

Remarks:

, animals #1, #2, #3

Time point:

24/48/72 h

Score:

3.3

Max. score:

4

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

animals #1, #2, #3

Time point:

24/48/72 h

Score:

3

Reversibility:

not reversible

Remarks on result:

probability of severe irritation

Interpretation of results:

other: Irritating

Conclusions:

Classification: risk of serious damage to eyes

Executive summary:

Glycolic acid (57% in aqueous solution and 12% NaCl) was irritating to rabbit eyes, and poses a risk of serious damage to eyes. The method used was Directive 84/449/EEC; B.5 “Acute toxicity (eye irritation)”.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Additional information

Skin irritation

The conclusion from the range of results is that glycolic acid is a dermal irritant, subject to concentration and pH, but may under some circumstances be corrosive to skin.

 

Glycolic acid >99% was evaluated in six female rabbits. The material was placed on two test sites of each rabbit for three minutes or one hour. The test material produced slight or mild erythema, but no oedema in the treated rabbits after the three-minute exposure. Necrosis was seen in three test sites after a one-hour exposure; mild to severe erythema and no to mild oedema were also seen. Necrosis was also seen in four test sites that were designated for a four-hour exposure but evaluated after an one-hour exposure; mild to moderate erythema and no to moderate oedema were seen in these test sites. Thus glycolic acid >99% is a skin corrosive when applied to shaved, intact rabbit skin.

 

An aqueous solution of 57% glycolic acid and 12% NaCl was applied (semi-occlusive) to the shaved skin of 3 white rabbits. The duration of exposure was 3 hours and the observation period was 14 days. The test substance was irritating to the skin

 

Glycolic acid 10% solution (buffered to pH 3.5):The test substance produced slight or mild erythema but no oedema in the treated rabbits after a 1 hour exposure period. All erythema resolved by day 6 after patch removal. One rabbit exhibited no dermal irritation after a 4 hour exposure period. However, sloughing of the skin was observed 6, 7 and 8 days after patch removal. Slight erythema but no oedema was observed only on the day of treatment in 2 rabbits after a 4 hour exposure period. One of these rabbits also exhibited sloughing 6 and 7 days after patch removal.

  

Glycolic acid 30% solution (buffered to pH 3.5.): The test substance produced no dermal effects in 1 rabbit after a 1 hour exposure period. Slight to moderate erythema was observed in the remaining 2 rabbits and resolved by 48 or 72 hours. One rabbit also exhibited superficial necrosis and mild oedema at 48 and 72 hours and sloughing at 6 and 7 days. The other rabbit exhibited superficial necrosis at 72 hours and sloughing at 6 days. One rabbit exposed for 4 hours exhibited no dermal effects, and no oedema was observed in any rabbit during the study. Slight or mild erythema was observed in the remaining 2 rabbits and resolved by 72 hours. One rabbit also exhibited superficial necrosis at 48 and 72 hours and sloughing at 72 hours and 6 days.

  

Glycolic acid 40% solution (buffered to pH 3.5.): One rabbit exposed for 1 hour exhibited slight erythema only at 1 hour after patch removal; no other dermal effects were observed in this rabbit. Slight or mild erythema but no oedema was observed in 1 rabbit and resolved by 72 hours. This rabbit exhibited sloughing 6 days after patch removal. Slight to moderate erythema and no or slight oedema were observed in the remaining rabbit, resolving by 6 days. Superficial necrosis was observed in this rabbit at 72 hours and 6 days and sloughing was observed at 6, 7 and 8 days. Exposure for 4 hours produced slight or mild erythema but no oedema in 2 rabbits. No erythema was observed by 72 hours. Epidermal scaling was observed in 1 of these rabbits at 6 days and in the other at 6 and 7 days. The remaining rabbit exhibited mild erythema through 72 hours. Superficial necrosis was observed in this rabbit at 48 and 72 hours and sloughing was observed at 72 hours and 6 days.

  

Glycolic acid 70% solution was evaluated in one female and five male rabbits for corrosion potential. The material was placed on two test sites of each rabbit for three minutes or one hour. The material produced no to mild erythema, but no oedema in the treated rabbits after the three-minute period. Necrosis was seen in two test sites after a one-hour exposure. Moderate or severe erythema and no to mild oedema were also seen. Necrosis was seen in three test sites that were designated for a four-hour exposure but evaluated after a one-hour exposure. Mild to severe erythema and no or mild oedema were also seen. Thus glycolic acid 70% solution was a severe corrosive agent on shaved, intact rabbit skin.

  

Eye irritation

Two albino rabbits were dosed by instillation of 0.1mL of glycolic acid into the right conjunctival sac of one eye. The test substance was left ‘in situ’ in the first rabbit; the eye of the second rabbit was rinsed for one minute with tap water 20 seconds after instillation. Ocular irritation was evaluated after 1 and 4 hours, 1, 2, 3, 7 and 14 days post-instillation. Effects were seen in the cornea, iris and conjunctiva one hour after dosing in both rabbits. By 14 days, observation was terminated because one treated (unwashed) eye, which had become very small, had no reaction to light. The other eye (washed) reacted to light although the cornea appeared as if it would rupture. Glycolic acid is corrosive to rabbit eyes. The study was conducted and reported prior to the introduction of test guidelines. In principle, the investigations meet the objectives of current guidelines, but much of the standard method detail is omitted. Use of the Draize assessment for ocular scoring is omitted. There is insufficient detail to determine average scores or reactions at 24 to 72 hours post-instillation. However, the information provided is sufficient to conclude the corrosive nature of the material and to justify the classification and labelling of glycolic acid. The results indicate that glycolic acid is corrosive to rabbit eyes.

  

An aqueous solution of 57% glycolic acid and 12% NaCl was instilled (0.1 mL) into the eye of 3 white rabbits. The untreated eye served as the control for each animal. The results were evaluated over the next 72 hours. It was observed that the effects on the cornea and conjunctivae were sufficient to classify the material as posing a risk of serious damage to eyes.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Justification for classification or non-classification

Based on the worst case results for skin and eye irritation, classification of glycolic acid as corrosive to skin at concentrations of 30 to 99% and corrosive to eyes at concentrations of greater than 57% are justified.

  

Under the conditions of the skin corrosion test, glycolic acid is considered to be corrosive to the skin. According to Regulation (EC) No 1272/2008, Glycolic acid is classified as skin corrosive category 1B and assigned the hazard statement H314 "causes severe skin burns and eye damage" with the pictogram GHS05.

 

Under the condition of the eye irritancy test, glycolic acid is considered to be corrosive to eyes. According to Regulation (EC) 1272/2008, glycolic acid is considered to cause damage to the eyes category 1 and is assigned the hazard statement H318 "Causes serious eye damage" with the pictogram GHS05.