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Administrative data

Description of key information

Acrylic acid is highly corrosive to skin and eyes. Acrylic acid may be irritating/corrosive to the respiratory tract.

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:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes
Specific details on test material used for the study:
- Name of test material (as cited in study report): acrylic acid glacial.
- Analytical purity: 99.8% pure (determined by GC)
- Lot/batch No.: Tank 8
Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Dr . K . Thomae GmbH, Biberach, FRG (animals 01, 02, 03 ), Boehringer Ingelheim Pharma KG (animals 04, 05)
- Age at study initiation: Young adult animals
- Housing: Single housing
- Diet (e.g. ad libitum): Kliba-Labordiaet, Klingentalmuehle AG, Kaiseraugst, Switzerland.
- Water (e.g. ad libitum): Tap water
- Acclimation period: Acclimatization for at least 1 week .



Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
unchanged (no vehicle)
Controls:
other: Untreated skin sites of the same animal.
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml

Duration of treatment / exposure:
3 minute(s)
Observation period:
1 h and 14 d
Number of animals:
5
Details on study design:
TEST SITE
- Area of exposure: Upper third of the back or flanks.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): The test substance was removed at the end of the exposure period with Lutrol(R)** and Lutrol(R)/water (1 :1) .
- Time after start of exposure: 3 min.


** Lutrol(R) E 400 = Polyethylenglycol DAB, BASF AG

SCORING SYSTEM: OECD TG 404 was used.
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
other: 24-48-72 h (mean)
Score:
2.7
Max. score:
4
Reversibility:
not reversible
Irritation parameter:
erythema score
Basis:
animal #4
Time point:
other: 24-48-72 h (mean)
Score:
3
Max. score:
4
Reversibility:
not reversible
Irritation parameter:
erythema score
Basis:
animal #5
Time point:
other: 24-48-72 h (mean)
Score:
3
Max. score:
4
Reversibility:
not reversible
Irritation parameter:
edema score
Basis:
animal #2
Time point:
other: 24-48-72 h (mean)
Score:
1.3
Max. score:
4
Reversibility:
not reversible
Irritation parameter:
edema score
Basis:
animal #4
Time point:
other: 24-48-72 h (mean)
Score:
2
Max. score:
4
Reversibility:
not reversible
Irritation parameter:
edema score
Basis:
animal #5
Time point:
other: 24-48-72 h (mean)
Score:
1.3
Max. score:
4
Reversibility:
not reversible
Other effects:
Tests with animals 01 and 03 were discontinued because of severe irritation. The finding was assessed by macroscopic
pathology indicating superficial necrosis and slight edema (animal 03) and discolouration of the application area (animal 01).
Gross- and histopathological examination of the skin of animal 02 was not performed.

Histopathological examination :
Animal 01 : Left flank : Severe swelling of collagen fibres in dermis and subcutis and pyknoses in the basal cell layer
Animal 03 : Left flank : Epidermal coagulation necrosis with edematous swelling of the dermis (no full thickness necrosis)
Animal 04 and 05 : Left flank : Focal deep necrosis (full thickness necrosis), loss of the epidermal adnexa in necrosis area, perifocal moderate epithelial hyperplasia , diffuse inflammatory reaction (corium to subcutis) in the application area.

Animal

Reading

Erythema

Edema

Comment

01

1h

-

2

-

02

1h

2

3

Erythema and Edema extending beyond the area of exposure

03

1h

-

3

­

04

1h

3

3

Erythema and Edema extending beyond the area of exposure

05

1h

3

3

Erythema and Edema extending beyond the area of exposure

Under the test conditions chosen and considering the described findings Acrylic acid glacial gives indication of causing full thickness destruction of skin tissue as a result of an exposure period of 3 minutes, when observation period is extended to 14 days, but not within an observation period of 1 hour .

Interpretation of results:
Category 1 (corrosive) based on GHS criteria
Conclusions:
Classification: highly corrosive (causes severe burns)
Endpoint conclusion
Endpoint conclusion:
adverse effect observed (corrosive)

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:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Principles of method if other than guideline:
BASF-Test
GLP compliance:
no
Specific details on test material used for the study:
- Name of test material (as cited in study report): Acrylic acid, raw, stabilised with approx. 0.2% phenothiazon.
- Analytical purity: 86%
- Composition of test material, percentage of components: Acrylic acid 86%, 2-propenoic acid, 2-carboxylethyl ester, 11%, water 2%,
phenothiazon 0.2%, unknown components 0.8%.
Species:
rabbit
Strain:
Vienna White
Vehicle:
unchanged (no vehicle)
Controls:
other: The adjacent eye was treated with one drop of physiological solution of sodium chloride and served as a control.
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied: approx. 50 µl


Duration of treatment / exposure:
21 days
Observation period (in vivo):
21 days
Number of animals or in vitro replicates:
2
Details on study design:
REMOVAL OF TEST SUBSTANCE
- Washing (if done): no

SCORING SYSTEM: The original BASF grading was converted into the numerical grading according to the OECD Draize system.

Irritation parameter:
other: Observation of eyes revealed inmmediate corrosion after treatment
Time point:
other: immediately after treatment
Score:
> 4
Reversibility:
not reversible
Other effects:
One drop of indiluted Acrylic acid caused a severe corrosion of the conjunctiva and cornea as a result of an exposure period of 10 minutes. In the course of 8 to 14 days, a complete destruction of the eye was observed and the animal was sacrificed.

One drop of indiluted Acrylic acid caused a severe corrosion of the conjunctiva and cornea as a result of an exposure period of 10 minutes. In the course of 8 to 14 days, a complete destruction of the eye was observed and the animal was sacrificed.

Interpretation of results:
Category 1 (irreversible effects on the eye) based on GHS criteria
Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Additional information

Skin irritation:

The potential of Acrylic acid glacial to cause acute dermal irritation or corrosion was assessed in a test according to OECD TG 404 by single topical application of 0.5 mL of the test substance to the intact skin of 5 White New Zealand rabbits for 3 minutes under semi-occlusive dressing.

In 2 animals brownish discolouration of the skin was observed. The observation period was terminated after the 1 hour - reading. The finding was assessed by macroscopic pathology indicating superficial necrosis and slight edema in one animal and discolouration of the application area in the other animal. Histopathological examination revealed epidermal coagulation necrosis with edematous swelling of the dermis (no full-thickness necrosis) in the first animal; severe swelling of collagen fibres in dermis and subcutis and pyknoses in the basal cell layer in the second animal.

The skin findings of the remaining three animals (erythema, edema, scaling or eczematoid skin alteration) were not reversible within 14 days after removal of the patches. The brownish discolouration of the skin of 2/3 animals was assessed by macroscopic pathology after 14 days (study termination) indicating skin lesion in the application area. Histopathological examination revealed focal deep necrosis (full thickness necrosis), loss of the epidermal adnexa in necrosis area, perifocal moderate epithelial hyperplasia and diffuse inflammatory reaction (corium to subcutis) in the application area.

Under the test conditions chosen and considering the described findings Acrylic acid glacial gives indication of causing full thickness destruction of skin tissue as a result of an exposure period of 3 minutes, when the observation period is extended to 14 days, but not within an observation period of 1 hour (BASF AG, 1998).

Acrylic acid is labelled R35 (highly corrosive) according to current EU regulations (Directive 67/548/EEC, Annex I and VI). Based on the presented test results, classification and labelling according to GHS (GHS UN rev.4, 2011) Skin corrosion/irritation Category 1A is proposed.

Eye irritation:

Hoechst Celanese Corp. performed an acute eye irritation study with acrylic acid neutralized with potassium hydroxide (forming a neutral 60% aqueous solution of potassium acrylate) which followed a modified Draize protocol. 9 animals were instilled with 0.1 mL of the test solution; the eyes of 3 animals were flushed with 20 mL of luke-warm water 2 seconds after instillation, the eyes of 3 animals were flushed with the same amount of water 4 seconds after instillation and 3 eyes were left unwashed. In addition, 1 animal was administered the same volume of test solution and the eye was flushed with 20 mL of luke-warm water 20 seconds later. Also, 1 animal was treated with 0.1 mL of the test solution and its eye flushed 4 seconds after instillation for a period of 1 minute.

In those eyes that were unwashed, severe ocular damage resulted with corneal opacities occurring after 1 hour and persisting for the duration of the study (18 days). Those eyes that were flushed 2 and 4 seconds after instillation all developed opacities (3/3), (3/3) but cleared after 7 days. In the eye that was flushed with 20 mL of luke-warm water 20 seconds after instillation of 0.1 mL of the test substance, corneal opacity resulted which persisted for the full duration of the study. Finally, instillation of the same amount of test substance followed 4 seconds later by flushing with luke-warm water for a period of 1 minute, resulted in corneal opacity which lasted until study termination (Hoechst Celanese Corp., 1992).

In addition, there is an older BASF report available. Instillation of 50 µL of the undiluted test substance (86 % acrylic acid) into a rabbit eye led to severe corneal opacity (OECD Draize score 3). Within 8 days complete destruction of cornea, conjunctiva and nictitating membrane was observed and both animals were sacrificed (BASF AG 1958).

The presented data give indication that the serious damage to eyes caused by acrylic acid is not solely due to the acidic properties of this chemical since a neutralized 60 % aqueous solution of potassium acrylate caused irreversible corneal opacity in rabbit eyes unless they were washed within few seconds. Based upon all of the presented evidence, acrylic acid may cause severe damage to the eyes.

Since Acrylic acid is already labelled R35 according to current EU regulations (Directive 67/548/EEC, Annex I) and classified in Skin corrosion/irritation Category 1A according to GHS (GHS UN rev.4, 2011) based on its corrosive properties, no further labelling with regard to eye irritation/corrosion is required.

Respiratory irritation:

In standard acute inhalation tests there was evidence that acrylic acid vapours were severely irritating to the eyes and respiratory tract of rats (BASF AG 1980, BAMM 1988). Silver et al. (1981) confirmed the respiratory irritancy of acrylic acid by measuring its effect on the respiratory frequency, tidal volume, minute ventilation, and rectal temperature as indices for irritancy. Based on the available data corrosion to the respiratory tract cannot be excluded.

Based on the presented test results, classification and labelling according to current EU regulations (Directive 67/548/EEC, Annex VI) R37and according to GHS (GHS UN rev.4, 2011) Specific Target Organ Toxicity Single Exposure Category 3 (Respiratory irritation) is proposed.


Effects on skin irritation/corrosion: highly corrosive

Effects on eye irritation: highly corrosive

Effects on respiratory irritation: highly irritating

Justification for classification or non-classification

EU classification according to Annex VI of Directive 67/548/EEC: C, R35, R37

GHS classification (GHS UN rev.4, 2011):

- Skin corrosion/irritation: Category 1A

- Specific target organ toxicity, Single exposure: Category 3 (May cause respiratory irritation)