Registration Dossier

Administrative data

Description of key information

n-hexyl methacrylate was tested with respect of its acute dermal irritant/corrosive properties following the patch test method. Method: according to Appraisal of the Safety of Chemicals in foods, drugs  and cosmetics, FDA Draize (1959) (Evonik Oil Additives GmbH, 1978)

In this study n-HMA is a slight to moderate skin irritant.

For the endpoint eye irritation no study with n-HMA was available. Therefore a read across using the category approach was used to predict the irritating properties of n-HMA.

n-HMA lies between BMA and 2-EHMA of the C1-C8 methacrylate esters. i-BMA and n-BMA are slightly irritating in the rabbit eye and 2-EHMA slightly to none irritating. Thus, it can be assumed that the eye irritating property of n-HMA lies also in-between as there are no further indicators for stronger irritation. For precautionary reasons n-HMA has to be regarded as slightly irritating in a worst case approach.

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:
guideline study with acceptable restrictions
Remarks:
Test procedure in accordance with national standard methods with acceptable restrictions. Restrictions: Observation period only 72 h, only two observations, duration of treatment 24 h instead of 4h.
Qualifier:
according to guideline
Guideline:
other: according to Appraisal of the Safety of Chemicals in foods, drugs and cosmetics, FDA Draize (1959)
Principles of method if other than guideline:
Information about the method, described in the study report ( Draize test: skin irritation/corrosion), is given in the free text field " Any other information materials and methods incl. tables".
GLP compliance:
no
Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: no data
- Age at study initiation: no data
- Weight at study initiation: mean value 2,5 kg
- Housing: individual housing
- Diet: ad libitum standard diet (Mümmel Z, Plange)
- Water: ad libitum
- Acclimation period: no data



ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 °C
- Humidity (%): 45 - 55 %
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hrs dark / 12 hrs light
Type of coverage:
occlusive
Preparation of test site:
other: shaved and shaved/abraded
Vehicle:
unchanged (no vehicle)
Controls:
other: Untreated skin areas of the test animals serve as the control (shaved, scarified).
Amount / concentration applied:
undiluted 0.5 mL (equal to 443 mg (density 0.886 g/cm3))
Duration of treatment / exposure:
24 hour(s)
Observation period:
24h and 72h post application
Number of animals:
6
Details on study design:
TEST SITE
- Area of exposure: 2.5 x 2.5 cm
- % coverage: 100% the whole torso of the animal was covered with a gummed bandage
- Type of wrap if used: gummed bandage to wrap up the body of the test animal.
REMOVAL OF TEST SUBSTANCE
- Removal of the test substance by removal of the adhesive tape and the bandage, no wash off

SCORING SYSTEM:
Erythema and Eschar Formation
No erythema: 0
Very slight erythema (barely perceptible): 1
Well defined erythema: 2
Moderate to severe erythema: 3
Very severe erythema (beef redness) to eschar formation preventing grading of erythema: 4
Maximum possible: 4

Edema Formation
No edema: 0
Very slight edema (barely perceptible) : 1
Slight edema (edges of area well defined by definite raising):2
Moderate edema (raised approximately 1mm): 3
Severe edema (raised more than 1mm and extending beyond area of exposure):4
Maximum possible: 4
Irritation parameter:
erythema score
Basis:
mean
Time point:
24/48/72 h
Score:
1.67
Max. score:
4
Reversibility:
not specified
Remarks on result:
other:
Remarks:
48 h value was not determined. No data in respect to reversibilty for times after exposure > 72h. Too short study duration to make a statement about reversibility. Only data of shaved skin have been used, data of shaved and scarified skin have not been used.
Irritation parameter:
edema score
Basis:
mean
Time point:
24/48/72 h
Score:
1.92
Max. score:
4
Reversibility:
not specified
Remarks on result:
other:
Remarks:
48 h value was not determined. No data in respect to reversibilty for times after exposure > 72h. Too short study duration to make a statement about reversibility. Only data of shaved skin have been used, data of shaved and scarified skin have not been used.
Irritant / corrosive response data:
Not reported
Other effects:
Not reported

Overall primary irritation score (PDII): 3.6 of 8 scores FDA (Draize), 1959,  

re-evaluated according to OECD 404

Reevaluation of the test results according to OECD404/GHS: only records for the shaved skin (not scarified) were considered  Erythema/ 24h     Erythema/72h  Oedema/24h  Oedema/72h
 animal 1  2  2  0  1
 animal 2  2  2  2  2
 animal 3  1  2  3  2
 animal 4  1  2  3  2
 animal 5  1  2  3  2
 animal 6  1  2  2  1
 average (single scores: animal 1-6)  1,34 2,000  2.17  1,67
 Primary irritation index I = Mean erythema score  (Erythema; 24h, 72h);  out of 4 scores  1,67  Primary irritation index II =  Mean oedema score (Oedema; 24h, 72h);   out of 4 scores  1,92  
 Overall average PDII out of 8 scores; For evaluation according to GHS classification system:  3,6    

Remarks concerning the study result: The study for acute skin irritation/  
corrosion was performed before OECD 404 came into force. For this reason the 
test values were reevaluated according to OECD criteria and test scores 
(erythema, oedema) obtained for the scarified skin were regarded as irrelevant.

  
Classification criteria according to the different classification systems:

EU-GHS:

Category 1: Corrosive subcategories

Corrosive in >= 1 of 3 animals
(applies to authorities not using subcategories): Corrosive
(only applies to some authorities)

Subcategory    Exposure                       Observation
------------------------------------------------------------
1A             <= 3 minutes                   <= 1 hour
1B             > 3 minutes to <= 1 hour       <= 14 days
1C             > 1 hour to <= 4 hours         <= 14 days
------------------------------------------------------------

A: Single harmonized corrosion category, using the results of animal testing.
A: Corrosive is a test substance that produces destruction of skin tissue, namely, 
visible necrosis through the epidermis and into the dermis, in at least 1 of 3 
tested animals after exposure up to 4 hours duration. Corrosive reactions are 
typified by ulcers, bleeding, bloody scrabs and, by the end of observation at 14 
days, by discoloration due to bleaching of the skin, complete areas of alopecia 
and scars. Histopathologic determinations should be consided evaluate questionable 
lesions.

Substances and/or mixtures are considered corrosive (Skin categorry 1) if it has
a pH of 2 or less or a pH of 11.5 or greater. If consideration of alkali/acid 
reserve suggests the substance or prepatration may not be corrosive despite the 
low or high pH value, then further testing needs to be carried out to confirm 
this, preferably by use of an appropriate validated in vitro test.

Category 2:

(1) Mean value of >= 2.3 to < 4.0 for erythem/eschar or for oedema in at least 2 
    of 3 animals from gradings at 24, 48 and 72 hours after patch removal or, if 
    reactions are delayed, from grades on 3 consecutive days after the onset of 
    skin reactions, or
(2) Inflammation that persits to the end of the observation period normally 14
    days in at least 2 animals, particularly taking into account alopecia 
    (limited area), hyperkeratosis, hyperplasia, and scalling, or
(3) In some cases where there is pronounced variability of response amoung 
    animals, with very definite positive effects related to chemical exposure
    in a single animal but less than the criteria above.

UN-GHS (additional category 3):

Category 3: Mild irritant (Applies to only some authorities for e.g. UN-GHS)

Mean value of >= 1.5 to < 2.3 for erythem/eschar or for oedema from gradings
in at least 2 of 3 tested animals from grades at 24, 48 and 72 hours or, if
reactions are delayed, from grades on 3 consecutive days after the onset of
skin reactions (when not included in the irritant category above).

According to the results of this dermal irritation study n-Hexylmethacrylate
has to be classified as follows:


According to EU-GHS (CLP): Hazard category: None (effects < 2.3 both erythem 
                        and oedema)
According to UN-GHS: Hazard category: 3 (Erythem > 1.5 but < 2.3, 24 hour 
                        exposition, no wash off the test substance)











   
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    

ems:

Classification criteria according to the different classification systems:

   

Classification criteria according to the different classification systems:

Classification criteria according to the different classification systems:

 

EU-GHS:

Category 1: Corrosive subcategories

  

Corrosive in >= 1 of 3 animals

(applies to authorities not using subcategories): Corrosive

(only applies to some authorities)

Subcat. Exposure                          Observation

1A    <= 3 minutes                      <= 1 hour

1B     > 3 minutes -- <= 1 hour  <= 14 days

1C     > 1 hour -- <= 4 hours      <= 14 days

A single harmonized corrosion category is provided in Table 3.2.1, using the results of animal

testing. A corrosive is a test material that produces destruction of skin tissue, namely, visible necrosis

through the epidermis and into the dermis, in at least 1 of 3 tested animals after exposure up to a 4 hour

duration. Corrosive reactions are typified by ulcers, bleeding, bloody scabs and, by the end of observation at

14 days, by discoloration due to blanching of the skin, complete areas of alopecia and scars. Histopathology

should be considered to discern questionable lesions.

 

A mixture is considered corrosive (Skin Category 1) if it has a pH of 2 or less or a pH of 11.5 or greater. If

consideration of alkali/acid reserve suggests the substance or preparation may not be corrosive despite the low or high pH value, then further testing needs to be carried out to confirm this, preferably by use of an appropriate validated in vitro test.

Interpretation of results:
GHS criteria not met
Remarks:
Classification: not irritating Criteria used for interpretation of results: EU
Conclusions:
n-Hexyl methacrylate was not irritating in a primary skin irritation study in rabbits (24-hour occlusive application, no wash of the
test substance). No data in respect to reversibilty for times after > 72h observation. Only data of shaved skin have been used, data of shaved and
scarified skin have not been used.
According to the results of this dermal irritation study n-Hexylmethacrylate has to be classified as follows:
According to EU-GHS (CLP): Hazard category: None (effects < 2.3 both erythem and oedema)
According to UN-GHS: Hazard category: 3 (Erythem > 1.5 but < 2.3, 24 hour application, no wash off the test substance) mildly irritating
Executive summary:

In a primary dermal irritation study New Zealand White rabbits were dermally exposed (intact and scarified skin) to

0.5 mL undiluted n-Hexyl methacrylate for 24 hours. Animals then were observed for 3 days. Irritation was scored by the method of Draize et al., 1959.

The mean erythema score (average value of  the single scores (animals 1-6; erythema; intact skin, 24h and 72h)  was determined to be 1.667 out of 4 and the mean oedema score was 1.9167 out of 4.   

Remarks concerning the study result: The study for acute skin irritation/corrosion was performed before OECD 404  came into force. For this reason the  test values were reevaluated according to OECD criteria and test scores  (erythema, oedema) obtained for the scarified skin were regarded as irrelevant.

According to the results of this dermal irritation study n-Hexylmethacrylate has to be classified as follows:

According to GefStoffV: slightly below the irritancy threshold (non-irritant, but 24 hour application, no wash off the test substance)

According to EU-GHS (CLP): Hazard category: None (effects < 2.3 both erythem and oedema)

According to UN-GHS: Hazard category: 3 (Erythem > 1.5 but < 2.3, 24 hour application, no wash off the test substance) mildly irritating.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Referenceopen allclose all

Endpoint:
eye irritation: in vivo
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study. The test followed recognized toxicology testing procedures and recognized scoring procedures of the results.
Justification for type of information:
The C1-C8 methacrylate esters are slight to mild irritants except for 2-EHMA, which is practically non to slightly irritating.
n-HMA lies between BMA and 2-EHMA of the C1-C8 methacrylate esters. i-BMA and n-BMA are slightly irritating in the rabbit eye and 2-EHMA slightly to none irritating. Thus, it can be assumed that the eye irritating property of n-HMA lies also in-between as there are no further indicators for stronger irritation. For precautionary reasons n-HMA has to be regarded as slightly irritating in a worst case approach.
Qualifier:
according to guideline
Guideline:
other: "Appraisal of the safety of chemicals in foods, drugs and cosmetics", Division of Pharmacology, FDA (Draize) (1959)
Deviations:
not specified
GLP compliance:
no
Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: no data
- Age at study initiation:
- Weight at study initiation: 2.4-2.6 kg
- Housing: no data
- Diet (e.g. ad libitum): Mümmel Z, Plange
- Water (e.g. ad libitum): tap water
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18
- Humidity (%): 45-55
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
0.1 ml
Duration of treatment / exposure:
Not rinsed
Observation period (in vivo):
24, 48 and 72 h, and 4, 5, 6 and 7 days
Number of animals or in vitro replicates:
6
Details on study design:
Six New Zealand White rabbits had 0.1 ml of undiluted test material  instilled into the conjunctival sac of the left eye. The right eye of  each rabbit, which remained untreated, served as a control. Animals were observed for irritating effects of the cornea, iris, conjunctivae 24, 48  and 72 hours and 4, 5, 6 and 7 days after treatment.

SCORING SYSTEM: Draize scale
Irritation parameter:
cornea opacity score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
4
Irritation parameter:
iris score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
2
Irritation parameter:
conjunctivae score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
3
Irritation parameter:
chemosis score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
4
Irritant / corrosive response data:
Except for some initial redness, none of the animals showed any effects of the treatment.
Interpretation of results:
GHS criteria not met
Remarks:
Classification: not irritating Criteria used for interpretation of results: other: REGULATION (EC) No 1272/2008 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 December 2008
Conclusions:
Classification: not irritating
Executive summary:

The ocular irritation that could be induced by 2-ethylhexyl methacrylate was evaluated in the rabbit according to the recommendations of the "Appraisal of the safety of chemicals in foods, drugs and cosmetics", Division of Pharmacology, FDA (Draize) (1959). A single application of 0.1 ml of 2-ethylhexyl methacrylate in its original form was placed into the conjunctival sac of one eye of six New-Zealand white rabbits. The ocular reactions were observed at 24, 48 and 72 hours and up to 7 days after the instillation. Mean values (24+48+72 h) for ocular irritation were: 0.0 for chemosis, enanthema, congestion and opacity. Under these experimental conditions, 2-ethylhexyl methacrylate was considered as not irritating when administered to the rabbit by ocular route.

Endpoint:
eye irritation: in vivo
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
The C1-C8 methacrylate esters are slight to mild irritants except for 2-EHMA, which is practically non to slightly irritating.
n-HMA lies between BMA and 2-EHMA of the C1-C8 methacrylate esters. i-BMA and n-BMA are slightly irritating in the rabbit eye and 2-EHMA slightly to none irritating. Thus, it can be assumed that the eye irritating property of n-HMA lies also in-between as there are no further indicators for stronger irritation. For precautionary reasons n-HMA has to be regarded as slightly irritating in a worst case approach.
Qualifier:
according to guideline
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes
Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: Lippische Versuchstierzucht, Hagemall GmbH & Co. KG
- Age at study initiation: 8-10 W
- Weight at study initiation: no data
- Housing: individually
- Diet (e.g. ad libitum): mümmel z, ssniff/Soest
- Water (e.g. ad libitum): tap water
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 +/- 2
- Humidity (%): 40 - 50
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
Amount applied: 0.1 ml
Duration of treatment / exposure:
The test eyes were not washed out following the instillation
Observation period (in vivo):
1, 24, 48 and 72 hours as well as 8 days 
Number of animals or in vitro replicates:
3
Details on study design:
REMOVAL OF TEST SUBSTANCE
- Washing (if done): no

SCORING SYSTEM: Draize scale

TOOL USED TO ASSESS SCORE: hand-slit lamp and fluorescein
Irritation parameter:
cornea opacity score
Basis:
animal: #1, #2, #3
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
other: Observation time: 8 days
Irritation parameter:
iris score
Basis:
animal: #1, #2, #3
Time point:
24/48/72 h
Score:
0
Max. score:
2
Remarks on result:
other: Observation time: 8 days
Irritation parameter:
conjunctivae score
Basis:
animal: #1, #3
Time point:
24/48/72 h
Score:
0.33
Max. score:
4
Reversibility:
fully reversible within: 48 h
Remarks on result:
other: Observation time: 8 days
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
other: Observation time: 8 days
Irritation parameter:
chemosis score
Basis:
animal: #1, #2
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
other: Observation time: 8 days
Irritation parameter:
chemosis score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0.33
Max. score:
4
Reversibility:
fully reversible within: 48 h
Remarks on result:
other: Observation time: 8 days
Irritant / corrosive response data:
One hour after dosing, two animals exhibited slight conjunctival redness, chemosis and discharge, which persisted for 24 hours in one animal.  The second animal also exhibited conjunctival redness at 24 hours after dosing.  At 48 hours following dosing all signs of irritation had resolved.  The remaining animal showed no signs of irritation at any time during the test.

Classification of eye irritation studies according GHS-criteria

 

Substance: n-Butyl methacrylate                     CAS: 97-88-1

 

Source: UNTER 88-022

 

 

Animal No.

Corneal opacity/Hornhauttrübung[Scores]

 

Mean Draize score in 2 of 3 animals

Reversibility

[scores]

Hazard category

after 24 h

after 48 h

after 72 h

in 7 days

in 21 days

 

1

0

0

0

0

0

 

 

2

0

0

0

0

0

 

 

3

0

0

0

0

0

 

 

 

 

 

 

0

 

 

none

 

 

 

 

 

 

 

 

Animal No.

Iritis/Regenbogenhautentzündung[Scores]

 

Mean Draize score in 2 of 3 animals

Reversibility

[scores]

Hazard category

after 24 h

after 48 h

after 72 h

in 7 days

in 21 days

 

1

0

0

0

0

0

 

 

2

0

0

0

0

0

 

 

3

0

0

0

0

0

 

 

 

 

 

 

0

 

 

none

 

 

 

 

 

 

 

 

Animal No.

Conjunctiva redness (erythem) /Bindehautrötung[Scores]

 

Mean Draize score in 2 of 3 animals

Reversibility

[scores]

Hazard category

after 24 h

after 48 h

after 72 h

in 7 days

in 21 days

 

1

1

0

0

0.33

0

 

 

2

0

0

0

0

0

 

 

3

1

0

0

0.33

0

 

 

 

 

 

 

 

 

 

none


 

Animal No.

Conjunctiva chemosis /Bindehautödem[Scores]

 

Mean Draize score in 2 of 3 animals

Reversibility

[scores]

Hazard category

after 24 h

after 48 h

after 72 h

in 7 days

in 21 days

 

1

0

0

0

0

0

 

 

2

0

0

0

0

0

 

 

3

1

0

0

0.33

0

 

 

 

 

 

 

 

 

 

none

 

 

Classification:

Hazard Category

 

none

Interpretation of results:
GHS criteria not met
Remarks:
not classified Criteria used for interpretation of results: other: REGULATION (EC) No 1272/2008 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 December 2008
Conclusions:
Classification: not irritating
Executive summary:

In an OECD 405 guideline study, n-butyl methacrylate (0.1 ml) was placed in the conjunctival sac of the right eye of three New Zealand White rabbits. The lids were then gently held together for one second. The test eyes were not washed out following the instillation. The left eye remained untreated for control. The eyes were examined at 1, 24, 48 and 72 hours as well as 8 days from beginning of test. Eye irritation was scored for signs of corneal damage (density, area), iris reaction and lesions of the conjunctivae (erythema, chemosis, discharge). Additionally, the cornea was examined with the aid of fluorescein after recording the observations at 24 hours. One hour after dosing, two animals exhibited slight conjunctival redness, chemosis and discharge, which persisted for 24 hours in one animal. The second animal also exhibited conjunctival redness at 24 hours after dosing. At 48 hours following dosing all signs of irritation had resolved. The remaining animal showed no signs of irritation at any time during the test. n-Butyl methacrylate is considered as slightly irritating to eyes.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Eye irritation

It is considered, that n-butyl methacrylate in its function as source material for the read across possess the potential for maximum slight irritation effects on the rabbit eye, which were below the criteria for classification according to 67/548/EEC and CLP / UN-GHS criteria, respectively.

No classification.

Please note: While the data support no classification, the CLP Annex VI entries still specify n-BMA as well as n-HMA as eye irritant, category 2.

Justification for classification or non-classification

n-hexyl methacrylate was not irritating in a valid primary skin irritation study in rabbits (24-hour occlusive application, no wash of the test substance). No data in respect to reversibilty for times after > 72h observation. Only data of shaved skin have been used, data of shaved and scarified skin have not been used.

The mean erythema score (average value of  the single scores (animals 1-6; erythema; intact skin, 24h and 72h)  was determined to be 1.667 out of 4 and the mean oedema score was 1.9167 out of 4. (Evonik Oil Additives GmbH, 1978) 

According to the results of this dermal irritation study n-Hexylmethacrylate has to be classified as follows:

According to EU-GHS (CLP): Hazard category: None (effects < 2.3 both erythem and oedema)

According to UN-GHS: Hazard category: 3 (Erythem > 1.5 but < 2.3, 24 hour application, no wash off the test substance) mildly irritating

In an OECD 405 guideline study, n-butyl methacrylate (0.1 ml) was placed in the conjunctival sac of the right eye of three New Zealand White rabbits (Schreiber and Wodtke, 1988). The lids were then gently held together for one second. The test eyes were not washed out following the instillation. The left eye remained untreated for control. The eyes were examined at 1, 24, 48 and 72 hours as well as 8 days from beginning of test. Eye irritation was scored for signs of corneal damage (density, area), iris reaction and lesions of the conjunctivae (erythema, chemosis, discharge). Additionally, the cornea was examined with the aid of fluorescein after recording the observations at 24 hours. One hour after dosing, two animals exhibited slight conjunctival redness, chemosis and discharge, which persisted for 24 hours in one animal. The second animal also exhibited conjunctival redness at 24 hours after dosing. At 48 hours following dosing all signs of irritation had resolved. The remaining animal showed no signs of irritation at any time during the test. n-Butyl methacrylate is considered as slightly irritating to eyes.

In summary, n-BMA causes only light irritation and is rated as non-irritant.

n-HMA lies between BMA and 2-EHMA of the C1-C8 methacrylate esters. The irritating potential is derived from both esters and is therefore regarded as non irritating.