Registration Dossier

Administrative data

Description of key information

Acrylic acid is of moderate toxicity after a single ingestion and after short-term inhalation exposure. Acrylic acid is not toxic after short-term skin contact, when tested in non-corrosive concentrations.
Oral: LD50 = between 1000 and 2000 mg/kg b.w. (male rats)
Dermal: LD50 > 2000 mg/kg bw (rabbit, occlusive)
Inhalation: LC50 > 5.1 mg/L (rat, vapour saturated atmosphere)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records
Reference
Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
Version / remarks:
2001
GLP compliance:
yes
Test type:
acute toxic class method
Limit test:
yes
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Lot No. A829F1C020
- Expiration date of the lot/batch: Jan 12, 2016
- Purity: 99.73 %
- Physical description: colourless clear, pungent liquid

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test substance was administered as a 20 %, 5 % or 2.5 % w/w mixture in distilled water.
Species:
rat
Strain:
Fischer 344
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories, Inc. on February 11, March 4, and April 22, 2015
- Age at study initiation: young adult, 9 - 11 weeks
- Weight at study initiation: 157 - 199 grams at experimental start
- Fasting period before study: overnight
- Housing: singly
- Diet (e.g. ad libitum): ad libitum (except during fasting), Harlan Teklad Global 16 % Protein Rodent Diet
- Water (e.g. ad libitum): ad libitum, filtered tap water
- Acclimation period: 9 - 19 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 23 °C
- Humidity (%): 40 - 57 %
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: To:
Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
VEHICLE
- Concentration in vehicle: The test substance was administered as a 20 %, 5 % or 2.5 % w/w mixture in distilled water.

MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg administered at a 20 % w/w mixture in distilled water
Doses:
2000 mg/kg as 20 % solution in distilled water
2000 mg/kg as 5 % solution in distilled water
300 mg/kg as 5 % solution in distilled water
1000 mg/kg as 2.5 % solution in distilled water
No. of animals per sex per dose:
300 and 1000 mg/kg: 6
2000 mg/kg: 3 animals for 20 % solution and 3 animals for 5 % solution
Control animals:
no
Details on study design:
- Duration of observation period following administration: short-term outcome: 48 h, long-term outcome: 14 days
- Frequency of observations and weighing: Individual body weights were recorded prior to the test substance administration (initial) and again on Days 7 and 14 (terminal) following dosing or after death. The animals were observed for mortality, signs of gross toxicity, and behavioural changes 30 min post-dosing and at least once daily thereafter for 14 days after dosing or until death occured.
- Necropsy of survivors performed: yes
- Other examinations performed: Observations included gross evaluation of skin and fur, eyes and mucous membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behaviour pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhea, and coma.
Statistics:
Statistical analysis was limited to the calculation of the mean density value for dosing.
Key result
Sex:
male
Dose descriptor:
LD50
Effect level:
ca. 1 000 - < 2 000 mg/kg bw
Based on:
test mat.
Mortality:
Mortality was observed in all animals tested with 2000 mg/kg (as 20 % and as 5 % solution) in distilled water.
One animal died after dosing of 1000 mg/kg as 2.5 % solution in distilled water.
Clinical signs:
All animals of the highest dose group showed hypoactivity with irregular respiration and hunched posture.
All animals of the test group with 1000 mg/kg showed hypoactivity with irregular respiration and reduced fecal volume. One animal additionally showed hunched posture and unthrifty appearance and was euthanized for humane reasons on day 12 after dosing.
All animals of the lowest dose group were active and healthy during the whole observation period.
Body weight:
One animal of the test group with 1000 mg/kg showed weight gain after 7 days post dosing.

Table 1: Individual Body Weights, Doses and Mortalities

Animal No.

Sex

Dose Level [mg/kg]

Body weight [g]

Dose [mL]

Mortality

Initial

Day 7

Day 14

Day

Weight [g]

3101

M

2000

164

-

-

1.61

1

163

3102

M

160

-

-

1.61

1

157

3103

M

157

-

-

1.61

1

154

3104

M

170

-

-

6.82

0

169

3105

M

176

-

-

7.12

0

174

3106

M

179

-

-

7.22

1

168

3107

M

300

199

230

258

1.23

S

-

3108

M

197

224

243

1.23

S

-

3109

M

194

226

243

1.23

S

-

3110

M

197

223

246

1.23

S

-

3111

M

192

190

200

1.23

S

-

3112

M

195

229

256

1.22

S

-

3113

M

1000

193

217

247

7.74

S

-

3114

M

191

145

-

7.64

12

138

3115

M

191

219

243

7.64

S

-

3116

M

188

217

236

7.54

S

-

3117

M

183

193

215

7.34

S

-

3118

M

192

218

234

7.74

S

-

S: Survived to study termination (euthanized via CO2inhalation after wighing on Day 14)

1: The test substance was administered as a 20 % w/w mixture in distilled water. Density 1.010 g/mL

2: The test substance was administered as a 5 % w/w mixture in distilled water. Density 0.998 g/mL. Due to the high volume of the dose solution to be administered (40.08 mL/kg), each animal’s dose was divided into two approximately equal portions and administered two hours apart.

3: The test substance was administered as a 5 % w/w mixture in distilled water. Density 0.998 g/mL.

4: The test substance was administered as a 2.5 % w/w mixture in distilled water. Density 1.003 g/mL. Due to the high volume of the dose solution to be administered (39.88 mL/kg), each animal’s dose was divided into two approximately equal portions and administered two hours apart.

Table 2: Individual Cage Side Observations

Animal Number

Dose Level [mg/kg]

Findings

Day of Occurence

3107 - 3112

300

Active and healthy

0 – 14

3113

1000

Active and healthy

Hypoactivity

Irregular respiration

Reduced fecal volume

0 (0.5-2.5 hrs), 4 - 14

0 (3 hrs) - 2

0 (3 hrs) - 3

1 - 3

3114

Active and healthy

Hypoactivity

Irregular respiration

Reduced fecal volume

Hunched posture

Unthrifty appearance

Euthanized for humane reasons

0 (0.5-2.5 hrs), 4 - 6

0 (3 hrs) – 3, 7

0 (3 hrs) – 3, 7 - 12

1 – 3

7

8 – 12

12

3115

Active and healthy

Hypoactivity, irregular respiration

Reduced fecal volume

0 (0.5-2.5 hrs), 4 - 14

0 (3 hrs), - 3

1

3116

Active and healthy

Hypoactivity, irregular respiration

Reduced fecal volume

0 (0.5 hrs), 2 - 14

0 (2.5 hrs), - 1

1

3117

Active and healthy

Hypoactivity, irregular respiration

Reduced fecal volume

0 (0.5 hrs), 3 - 14

0 (2.5 hrs), - 1

1 - 2

3118

Active and healthy

Hypoactivity, irregular respiration

Reduced fecal volume

0 (0.5-2.5 hrs), 2 - 14

0 (3 hrs), - 1

1

3101 – 3103

2000

Hypoactivity, irregular respiration

Hunched posture

Dead

0 (0.5-5.5 hrs)

0 (3 – 5.5 hrs)

1

3104, 3105

Active and healthy

Hypoactivity, irregular respiration

Hunched posture

Dead

0 (0.5 hrs)

0 (1.5 – 3 hrs)

0 (2.5 – 3 hrs)

0 (5 hrs)

3106

Active and healthy

Hypoactivity, irregular respiration

Hunched posture

Dead

0 (0.5 hrs)

0 (1.5 – 5 hrs)

0 (2.5 – 5 hrs)

1

Interpretation of results:
Category 4 based on GHS criteria
Remarks:
Acute Oral LD50 is between 1000 and 2000 mg/kg b.w.
Conclusions:
An acute oral toxicity test (Acute Toxic Class Method) was conducted with rats to determine the potential for the test substance to produce toxicity from a single dose via the oral route. Under the conditions of this study, the acute oral LD50 of the test substance is between 1000 and 2000 mg/kg of body weight in male rats.
Executive summary:

A Limit Test was conducted using a starting dose level of 2000 mg/kg administered at a 20 % w/w mixture in distilled water to three healthy male rats by oral gavage. Due to mortality in these animals, three additional males were dosed at the same dose level administered at a 5 % w/w mixture in distilled water. Since all of these animals died, six additional animals in two consecutive groups of three rats each were dosed at the next lowest dose level of 300 mg/kg at a 5 % w/w mixture in distilled water. At the request of the Sponsor, a dose level of 1000 mg/kg administered at 2.5 % w/w mixture in distilled water to three healthy male rats by oral gavage. Due to mortality in one animal, three additional males were dosed at the same dose level administered at a 2.5 % w/w mixture in distilled water. Since the animals survived, no additional testing was required. All animals were observed for mortality, signs of gross toxicity, and behavioural changes at least once daily for 14 days after dosing or until death occured. Body weights were recorded prior to administration (initial) and again on Days 7 and 14 (terminal) following dosing or after death. Necropsies were performed on all animals.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
Value:
2 000 mg/kg bw

Acute toxicity: via dermal route

Link to relevant study records
Reference
Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
08. Feb. - 22. Feb. 2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study
Qualifier:
according to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
other: U.S. EPA Health Effects Test Guidelines, OCSPP 870.1200
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Specific details on test material used for the study:
Composition: 20% acrylic acid Lot # 0104111S09
80% deionized water
Physical description: Clear colorless liquid
Solubility: Soluble in water.
Stability: Test substance was expected to be stable for the duration of testing.
Expiration Date: January 4, 2012
Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Robinson Services, Inc.
- Age at study initiation: 13 weeks
- Weight at study initiation: 1937 - 2221 g (males), 1814 -2176 g (females)
- Fasting period before study:
- Housing: The animals were singly housed in suspended stainless steel caging with mesh floors, which conform to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011). Litter paper was placed beneath the cage and was changed at least three times per week.
- Diet (e.g. ad libitum): Purina Rabbit Chow #5326
- Water (e.g. ad libitum): Filtered tap water was supplied ad libitum by an automatic water dispensing system.
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22°C
- Humidity (%): 22-38 %
- Air changes (per hr): 10 - 14
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle
Type of coverage:
occlusive
Vehicle:
water
Details on dermal exposure:
Two thousand mg/kg of body weight of a 20% aqueous dilution of the test substance in distilled water (v/v) was applied evenly over a dose area of approximately 2 inches x 3 inches (approximately 10% of the body surface) and covered with a 4-inch x 8-inch, 6-ply gauze pad. The gauze pad and entire trunk of each animal were then wrapped with 3-inch Durapore tape to avoid dislocation of the pad and to minimize loss of the test substance. The rabbits were then returned to their designated cages. The day of application was considered Day 0 of the study. After 24 hours of exposure to the test substance, the pads were removed and the test sites were gently cleansed of any residual test substance.
Duration of exposure:
24 hours
Doses:
2000 mg/kg of body weight of a 20 % aqueous dilution of th etest substance in distilled water
No. of animals per sex per dose:
5
Control animals:
not required
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for mortality, signs of gross toxicity, and behavioral changes during the
first several hours after application and at least once daily thereafter for 14 days. Observations included gross evaluation of skin and fur, eyes and mucous
membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behavior pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhea, and coma. Individual body weights of the animals were recorded prior to test substance application
(initial) and again on Days 7 and 14 (termination).
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
None
Clinical signs:
Other than the dermal irritation, discoloration, fissuring and/or mechanical damage noted at the dose site of all animals throughout the 14-day observation period, there were no other clinical findings recorded for any animal over the course of the observation period.
Body weight:
Increased as expected for all animals over the course of the study.
Gross pathology:
No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.
Other findings:
none reported

Animal No.

Sex

Body weight (g)

Dose1

Initial

Day 7

Day 14

mL

3801

M

1955

2124

2296

19.2

3802

M

2104

2288

2404

20.7

3802

M

2221

2287

2409

21.8

3804

M

1937

2071

2142

19.0

3805

M

2008

2042

2189

19.7

3806

F

2176

2344

2513

21.4

3807

F

2007

2167

2389

19.7

3808

F

2009

2064

2218

19.7

3809

F

1814

1946

2092

17.8

3810

F

2046

2086

2286

20.1

 

1The test substance was applied as a 20% v/v mixture in distilled water. Specific Gravity - .1.017 g/mL

 

Interpretation of results:
GHS criteria not met
Conclusions:
LD50 of test item is greater than 2,000 mg/kg of body weight of a preparation of 20% Acrylic Acid in Water.
Executive summary:

An acute dermal toxicity test was conducted with rabbits to provide information on the potential health hazards from short term exposure to acrylic acid at non-corrosive concentrations via the dermal route. This study was conducted to confirm the results from earlier research which was conducted under non GLP conditions. Acid was tested as a preparation of 20% Acrylic Acid in Water to produce toxicity from a single topical application. Under the conditions of this study, the single dose acute dermal LD50 of the acrylic acid is greater than 2,000 mg/kg of body weight in male and female rabbits. All animals survived exposure to 2,000 mg/kg acrylic acid and gained body weight during the study. Dermal irritation, discoloration, fissuring, and/or mechanical damage was noted at the dose site of all animals throughout the 14 -day observation period. There were no other findings recorded for any animal over the course of the observation period, also necropsy did not show gross abnormalities.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
discriminating dose
Value:
2 000 mg/kg bw

Additional information

Oral exposure route:

A Limit Test was conducted using a starting dose level of 2000 mg/kg administered at a 20 % w/w mixture in distilled water to three healthy male rats by oral gavage. Due to mortality in these animals, three additional males were dosed at the same dose level administered at a 5 % w/w mixture in distilled water. Since all of these animals died, six additional animals in two consecutive groups of three rats each were dosed at the next lowest dose level of 300 mg/kg at a 5 % w/w mixture in distilled water. At the request of the Sponsor, a dose level of 1000 mg/kg administered at 2.5 % w/w mixture in distilled water to three healthy male rats by oral gavage. Due to mortality in one animal, three additional males were dosed at the same dose level administered at a 2.5 % w/w mixture in distilled water. Since the animals survived, no additional testing was required. All animals were observed for mortality, signs of gross toxicity, and behavioural changes at least once daily for 14 days after dosing or until death occured. Body weights were recorded prior to administration (initial) and again on Days 7 and 14 (terminal) following dosing or after death. Necropsies were performed on all animals.

In an acute toxicity study conducted by BASF AG (1958) groups of 1 - 5 rats were administered doses of 20 - 5010 mg/kg bw by gavage and observed for 7 days for lethality and clinical signs of intoxication. The mortality rate was 0/1, 0/1, 0/1, 1/4, 4/5, 5/5, and 1/1 at 20, 79, 316, 1260, 2040, 3160, 5010 mg/kg bw, respectively. The LD50 was found to be approx. 1500 mg/kg bw. Clinical symptoms were unspecific: abdominal position. No necropsy was performed or documented.

 

The acute toxicity of acrylic acid to SPB (Sprague-Dawley) and CDF (Fisher 344-derived) rats by the oral route was investigated in a well-documented, GLP-compliant study by Dow Chemical (1980). Groups of 5 rats/sex/strain/dose level received the undiluted test compound by single-dose oral gavage. The following dose levels were chosen for testing in one or both strains: 31.6, 63, 126, 158, 316, 630, 1260, 1580, 2000, 2520, 5000 mg/kg bw. For reasons of animal welfare, not all dose levels were tested in both strains and both sexes. LD50 values were calculated for male and female Sprague-Dawley, and male and female CDF rats, respectively. Using Moving Average analysis, the LD50 values were determined to be 1337, 718, 151, and 526 mg/kg bw, respectively. Using Probit analysis, the respective LD50 values were 1405, 617, 146, and 468 mg/kg bw. Thus, the LD50 in Sprague-Dawley rats was 617-1405 mg/kg bw (Probit), and in CDF rats 146-468 mg/kg bw (Probit). With respect to clinical signs and the gross-pathological investigation, no detailed information was given.

 

In addition, Carpenter et al. (1974) published a LD50 of approx. 357 mg/kg bw in Wistar rats by single-dose oral gavage.

Other acute oral LD50s in rats, rabbits and mice were described mostly without additional data and ranged between 250 and 1350 mg/kg bw (BASF AG 1958, Klimkina 1969, Majka 1974).

 

Dermal exposure route:

An acute dermal toxicity test was conducted with rabbits to provide information on the potential health hazards from short term exposure to acrylic acid at non-corrosive concentrations via the dermal route. Acid was tested as a preparation of 20% Acrylic Acid in water to produce toxicity from a single topical application. Under the conditions of this study, the single dose acute dermal LD50 of the acrylic acid is greater than 2,000 mg/kg of body weight in male and female rabbits. All animals survived exposure to 2000 mg/kg acrylic acid and gained body weight during the study. Dermal irritation, discoloration, fissuring, and/or mechanical damage were noted at the dose site of all animals throughout the 14 -day observation period. There were no other findings recorded for any animal over the course of the observation period, also necropsy did not show gross abnormalities.

 

These results thus indicate that deaths observed at lower dose levels in earlier studies (described below) were likely due to the extensive local corrosivity, and not to systemic toxicity. This is furthermore supported by the absence of adverse effects in chronic dermal toxicity studies with acrylic acid.

 

Acute dermal toxicity using undiluted acrylic acid is dominated by the severe local corrosivity caused by dermal contact; dermal LD50 values of approx. 748 mg/kg bw (Carpenter et al. 1974) and approx. 640 mg/kg bw (BASF AG 1979) were demonstrated for New Zealand White and White Vienna rabbits, respectively.

 

Carpenter (1974) used 3 doses (420, 840, 1680 mg/kg bw) of undiluted acrylic acid with a 24 hour contact period under occlusive conditions (impervious sheeting). Starting with the exposure animals were immediately highly agitated and crying. Necrosis was recorded for all contact sites. After application of 420 mg/kg 1/4 animals died within 24 hours, 2 of 4 animals at 840 mg/kg and 4 of 4 animals at 1680 mg/kg, also within 24 hours.

 

In the BASF study doses of 400 and 640 mg/kg bw of undiluted acrylic acid were applied under occlusive conditions for 24 hours to the skin of 5 male and 5 female White Vienna rabbits per dose. After application of 400 mg/kg 1/5 males and 1/5 females died on day 7 or later; after application of 640 mg/kg 2/5 males and 3/5 females died within 24 hours. In addition to severe local necrosis, the treated animals showed apathy, dispnoea and poor general state. Necropsy demonstrated dilatation and acute hyperaemia of the heart and lung oedema in the deceased animals. The dilatation of the right cardiac ventricle together with an acute congestion of the heart is a common finding due to acute cardiovascular failure. In the present study, the animals revealed a massive acute skin necrosis. The massive skin necrosis led to massive pain accompanied by centralisation of blood and cardiovascular imbalance leading finally to a shock. Shock is the final common pathway for several potentially lethal clinical events, including extensive trauma. Shock is characterized by systemic hypotension due to either reduced cardiac output or reduced effective circulating blood volume. Animals, which died due to a cardiovascular failure during shock reveals also an acute congestion of heart

 

Both studies were rated with a ‘not assignable’ (Klimisch 4) reliability as the test was conducted at corrosive concentrations. Mortality observed is considered as a secondary effect arising from local severe skin damage and not from true systemic toxicity of acrylic acid.

 

The severity of corrosive effects of undiluted acrylic acid is also indicated in irritation/corrosivity studies listed under IUCLID section 7.3. The key study (BASF AG, 1998) reports full thickness destruction of skin tissue as a result of a 3 minutes exposure of rabbit skin to undiluted acrylic acid. Furthermore, tests with 2 of the animals had to be discontinued because of the severe irritation. In a second study, undiluted acrylic acid also induced full thickness destruction of skin tissue with scar formation as a result of an exposure period of even 1 minute. After application of the undiluted test substance for 5 and 15 min, respectively, anaemic necrosis followed by formation of deep scars was observed (BASF AG, 1958).

 

In conclusion, results from acute dermal toxicity testing with undiluted acrylic acid with an exposure period of 24 hours under occlusive conditions are compromised by severe corrosion, inducing inter alia pain and shock in exposed animals. Rabbits clearly showed signs of severe stress and pain (see e.g. Carpenter 1974). Thus, effects reported in these studies cannot be attributed to an intrinsic toxic property of the test substance induced by exposure via the dermal route.

 

Inhalation exposure route:

In an acute inhalation study groups of 10 Sprague-Dawley rats per sex were exposed by head-nose exposure to saturated vapour atmospheres at concentrations of 4.25 and 5.12 mg/L (analysed) for 4 hours and observed for 14 days (BASF AG 1980). No rats died during exposure or during the 14-day post-exposure period. Clinical signs of toxicity included: reddish periocular and perinasal lacrimination, salivation, eyelid closure, scrubby clotted skin and dyspnoea. The animals of both groups were 4 and 5 days respectively after the exposure without findings. No macroscopic lesions were observed in animals sacrificed at the end of the 2-week post exposure period. Thus, the 4- hour rat LC50 was > 5.1 mg/L.

 

In addition, an Inhalation Hazard Test was performed (BASF AG, 1979). Several groups of 3 Sprague-Dawley rats per sex were exposed sequentially to saturated acrylic acid vapours for different time periods (30 min, 1 and 3 hours) at 20 °C. The exposure time not causing lethality was determined. No analytical determination of the atmosphere concentrations was performed. Nominal test substance concentrations were: 21.5 mg/L (30 min and 1 h) and 22.5 mg/L (3h). Since the saturated vapour concentration of acrylic acid was estimated to be approx. 12.8 mg/L, the actual vapour concentrations of acrylic acid were either lower than the nominal concentrations, or the test substance was at least partially present as aerosol in the test atmosphere. No mortality was observed after 30 min exposure. After 1 h and 3 h 1/6 and 6/6 animals died, respectively. Clinical signs included: eyelid closure, salivation, periocular and reddish perinasal lacrimination, clotted eyes, dyspnoea, corneal opacity, diminished pain reflex, tremulous and tottered movement, nose and eye corrosion, and scrubby fur.

 

In addition, Battelle conducted a single dose inhalation toxicity study in Cynomolgus monkeys in compliance with the EPA guidelines (40 CFR Part 792) (Rohm & Haas Co., 1995). Five groups of primates, three animals each, were exposed via head-only inhalation exposure to a common target vapour concentration (75 ppm) of the test substance or filtered air (control). Each animal received a single exposure of either three or six hour duration. The achieved mean test substance vapour concentration values were all within 8 % of the target concentration and the percent relative standard deviations were all less than 10 percent. The inhaled dose was calculated for each animal based on its body weight, mean test substance concentration value and total inhaled volume. The individual animal inhaled doses for Acrylic acid ranged from 12.7 mg/kg bw (animal #401) to 35.2 mg/kg bw (animal #503). All animals survived the exposures in good condition. No clinical signs of toxicity were observed and no treatment related findings were observed during the gross pathological examination.

Justification for selection of acute toxicity – dermal endpoint
In this study acrylic acid was tested for its potential toxicity after dermal exposure in non-corrosive concentrations up to the maximum dose level of 2000 mg/kg b.w..

Justification for classification or non-classification

EU classification according to Annex I of Directive 67/548/EEC: Xn, R20/21/22

GHS classification (GHS UN rev.5, 2013):

- Oral route: Acute Category 4

- Inhalation route (vapour): Acute Category 4