Registration Dossier

Administrative data

Description of key information

Two in vivo skin irritation studies in rabbits (GLP and EPA  OPP 81-5) were available. In a key guideline study 3-methoxy-3-methylbutan-1-ol was considered non-irritant. In a 28 day study in which the substance was applied for 23 hours per day, the substance was considered to be slightly irritating. However, according to regulation EC No 1272/2008 the substance is classified as non-irritant.  In an in vivo eye irritation study in rabbits (GLP and EPA OPP 81-4) 3-methoxy-3-methylbutan-1-ol was considered eye irritating.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records
Reference
Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1991
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The study was conducted according to an appropriate test method and in compliance with GLP, but the purity of the samples is not known. Consequently, the reliability of the data is with restriction.
Qualifier:
according to
Guideline:
EPA OPP 81-5 (Acute Dermal Irritation)
GLP compliance:
yes
Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Interfauna UK Limited, Abbots Ripton Road, Wyton, Huntingdon
- Age at study initiation: adult, young
- Diet (e.g. ad libitum): Standard Rabbit Diet (Special Diets Services, 1 Stepfield, Witham, Essex, CM8 3AD
- Water (e.g. ad libitum): ad libitum (tap water)
- Acclimation period: 7 days before test commencement

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 1´9 °C
- Humidity (%): 52 % rel.
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hours dark/12 hours light
Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
other: unchanged (no vehicle) and water
Controls:
yes
Amount / concentration applied:
0.5 ml
Duration of treatment / exposure:
4 hour(s)
Observation period:
Skin reactions were assessed 1, 24, 48 and 72 hours after patch removal
Number of animals:
6 (male)
Details on study design:
The test and control materials (0.5 ml) were applied to intact skin on each rabbit under 2.5 cm*2.5 cm patches of gauze. The test material, Solfit, was applied at concentrations of 100% and 50% (v/v) in distilled water and 2 control material, triethyl citrate and distilled water, were also applied. Four patches were applied to each rabbit. The patches were then covered with Micropore tape and the trunk was loosely bound with Elastoplast Elastic Bandage which remained in position for 4 h. At the end of this period the patches were removed and the skin wiped with damp tissues without altering the existing response or the integrity of the epidermis.
Skin reactions were assessed 1, 24, 48 and 72 h after patch removal using the scoring system as shown below.

Grading and scoring of the dermal reactions were performed using the prescribed numerical scoring system as follows:

Erythema and eschar formation:
No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) to slight eschar formation (injuries 4
in depth)

Oedema formation:
No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of area well-defined by definite raising) 2
Moderate oedema (raised approximately 1 millimetre) 3
Severe oedema (raised more than 1 millimetre and extending 4
beyond the area of exposure)

Assessment of Results
The mean irritation score for each material was calculated in the following way:
The daily scores for erythema/eschar and oedema were totalled at the end of the experimental period and divided by the number of animals (6 ) and the number of time points (4 ).
Irritation parameter:
overall irritation score
Basis:
mean
Score:
0.04
Reversibility:
fully reversible
Remarks on result:
other: 100% concentration
Irritation parameter:
overall irritation score
Basis:
mean
Score:
0
Reversibility:
fully reversible
Remarks on result:
other: <50% concentration

Mean irritation scores were calculated to be:

 Solfit - 100%  0.04
 Solfit - 50% (v/v) in distilled water  0.00
 Triethyl citrate  0.00
 Distilled water  0.00

Primary Skin Irritation Test in Rabbits Reaction Scores:

 Rabbit    number  Material              Erythema           Oedema
 1h  24h  48h  72h  1h  24h  48h  72h
 1           A  0  0  0  0  0  0  0  0
 B  0  0  0  0  0 0  0  0
 C  0  0  0  0  0  0  0
 D  0  0  0  0  0  0  0
          2  A  0  0  0  0  0  0  0  0
 B  0  0  0  0  0  0  0  0
 C  0  0  0  0  0  0  0
 D  0  0  0  0  0  0  0
          3  A  0  0  0  0  0  0  0  0
 B  0  0  0  0  0  0  0  0
 C  0  0  0  0  0  0  0  0
 D  0  0  0  0  0  0  0  0
          4  A  0  0  0  0  0  0  0
 B  0  0  0  0  0  0  0  0
 C  0  0  0  0  0  0  0  0
 D  0  0  0  0  0  0  0  0
          5  A  0  0  0  0  0  0  0
 B  0  0  0  0  0  0  0  0
 C  0  0  0  0  0  0  0  0
 D  0  0  0  0  0  0  0  0
          6  A  0  1  0  0  0  0  0
 B  0  0  0  0  0  0  0  0
 C  0  0  0  0  0  0  0
 D  0  0  0  0  0  0  0

A = Solfit 100%; B = Solfit 50% (v/v) in distilled water; C = Triethylcitrate; D = Distilled water


At a concentration of 100% very slight erythema was noted at one animal at 24 hours assessment only. No skin reactions
were noted at a concentration of 50% v/v in distilled water. No skin reactions were noted with the control materials, 
triethyl citrate and distilled water.

Interpretation of results and classification of substance Classification of the substance is based on the criteria laid down in: Regulation 1272/2008 EC, Annex I, table 3.2.2.

Interpretation of results:
not irritating
Conclusions:
In conclusion, 3-methoxy-3-methylbutan-1-ol is non-irritant to rabbit skin under the test conditions.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records
Reference
Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1991
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The study was well documented and meets generally accepted scientific principles, and conducted in compliance with GLP, but the purity of the samples is not known. Consequently, the reliability of the data is with restriction.
Qualifier:
according to
Guideline:
EPA OPP 81-4 (Acute Eye Irritation)
GLP compliance:
yes
Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: Interfauna UK Limited, Abbots Ripton Road, Wyton, Huntingdon
- Age at study initiation: adult, young
- Diet (e.g. ad libitum): Standard Rabbit Diet (Special Diets Services, 1 Stepfield, Witham, Essex, CM8 3AD
- Water (e.g. ad libitum): ad libitum (tap water)
- Acclimation period: 32 days before test commencement

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 18 °C
- Humidity (%): 46% rel.
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hours dark/12 hours light
Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
One eye of each animal was dosed with 0.1 ml test material, while the other eye served as an untreated control.
Amount applied: 0.1 ml
Duration of treatment / exposure:
Rinsed Group:
The test material was instilled in one rabbits eye and 30 to 60 second after instillation the treated eye was rinsed with ca. 100 ml of distilled water. The rabbit was observed up to 24 h after instillation for signs of severe irritation. As none were noted, the remaining 2 rabbits were then treated in the same manner.
Non-rinsed group:
One rabbit was treated first and observed up to 24 h after instillation for signs of severe instillation. As none were noted, the remaining 5 rabbits were then treated.
Observation period (in vivo):
All treated and control eyes were graded and scored at approx. 1, 24, 48 and 72 h after instillation. Further assessment was carried out at 7, 9 and 10 days (non-rinsed group) and 4, 7 and 11 days (rinsed group) until reversibility was established.
Number of animals or in vitro replicates:
9 (male animals)
Irritation parameter:
cornea opacity score
Basis:
mean
Time point:
24/48/72 h
Score:
0.83
Max. score:
4
Reversibility:
fully reversible within: 11 days
Remarks on result:
other: rinsed group
Irritation parameter:
iris score
Basis:
mean
Time point:
24/48/72 h
Score:
0.58
Max. score:
1
Reversibility:
fully reversible within: 11 days
Remarks on result:
other: rinsed group
Irritation parameter:
conjunctivae score
Basis:
mean
Time point:
24/48/72 h
Score:
1.8
Max. score:
2
Reversibility:
fully reversible within: 11 days
Remarks on result:
other: rinsed group
Irritation parameter:
chemosis score
Basis:
mean
Time point:
24/48/72 h
Score:
2
Max. score:
3
Reversibility:
fully reversible within: 11 days
Remarks on result:
other: rinsed group
Irritation parameter:
cornea opacity score
Basis:
mean
Time point:
24/48/72 h
Score:
0.48
Max. score:
4
Reversibility:
fully reversible within: 10 days
Remarks on result:
other: non-rinsed group
Irritation parameter:
iris score
Basis:
mean
Time point:
24/48/72 h
Score:
0.88
Max. score:
1
Reversibility:
fully reversible within: 10 days
Remarks on result:
other: non-rinsed group
Irritation parameter:
conjunctivae score
Basis:
mean
Time point:
24/48/72 h
Score:
1.88
Max. score:
3
Reversibility:
fully reversible within: 10 days
Remarks on result:
other: non-rinsed group
Irritation parameter:
chemosis score
Basis:
mean
Time point:
24/48/72 h
Score:
1.75
Max. score:
2
Reversibility:
fully reversible within: 10 days
Remarks on result:
other: non-rinsed group

Rinsed Group

    animal number           Region of the eye     one hour                 day after instillation
 1  2  3  4  7  11
              19       Cornea  degree/opacity  2  1  0  2  2  0  0
 area/opacity  4  4  0  2  2  0  0
 Iris    0  0  1  1  1  0  0
       Conjunctivae  redness  2  2  2  2  2  1  0
 chemosis  3  2  2  2  2  1  0
 discharge  1  1  1  1  1  *  
20                     Cornea  degree/opacity  0  0  0  0  0  0  
 area/opacity  0  0  0  0  0  0  
 Iris    1  1  1  0  0  0  
       Conjunctivae  redness  2  2  2  1  1  0  
 chemosis  2  2  2  2  1  0  
 discharge  1  1  1  *  *  *  
                21 Cornea      degree/opacity  0  1  0(D)  0  0  0  
 area/opacity  0  4  0  0  0  0  
 Iris    0  1  0  1  0  0  
       Conjunctivae  redness  2  2  1  1  0  
chemosis   3  2  1  1  1  0  
 discharge  1  2  *  *  *  *  

*=no discharge; D=dullness

non-rinsed Group

    animal number           Region of the eye     one hour                 day after instillation
 1  2  3  7  9  10
           13      Cornea      degree/opacity  0  1  0(D)  0(D)  0    0
 area/opacity  0  4  0  0  0    0
 Iris    0  1  1  1  0    0
       Conjunctivae  redness  2  2  2  2  1    0
 chemosis  2  1  1  0    0
 discharge  1  1  1  Tw  *    *
14                 Cornea      degree/opacity  0  1  1  1  0    
 area/opacity  0  4  4  4  0    
 Iris    1  1 1  1  0    
Conjunctivae         redness  2  3  2  2  0    
 chemosis  3  1  2  2  0    
 discharge  2  *  1  1  *    
15                     Cornea  degree/opacity  0  0(D)  0(D)  0(D)  0    
 area/opacity  0  0  0  0  0    
 Iris    1  1  1  1  0    
Conjunctivae         redness  2  2  1  2  0    
 chemosis  3  1  2  1  0    
discharge   2  1  Tw  2  *    
16                     Cornea  degree/opacity  0  0(D)  0(D)  0(D)  0  0  
 area/opacity  0  0  0  0  0  0  
 Iris    1  1  1  1  0  0  
       Conjunctivae  redness  3  2  1  2  1  0  
 chemosis  4  1  1  2  0  0  
 discharge  3  1  1  *  *  
          17           Cornea  degree/opacity  0  1  0  0  0    
 area/opacity  0  2  0  0  0    
 Iris    1  1  1  1  0    
       Conjunctivae  redness  2  2  1  1  0    
 chemosis  3  2  1  1  0    
 discharge  2  1  1  *  *    
               18      Cornea  degree/opacity  0(D)  0(D)  0  0    
 area/opacity  0  0  0  0  0    
 Iris    1  1  0  0  0    
       Conjunctivae  redness  2  2  1  2  0    
 chemosis  4  2  1  1  0    
 discharge  2  2  1  *  *    


*=no discharge; Tw = thick white discharge; D = Dullness

Rinsed group:
The 3 rinsed eyes showed slight to moderste corneal opacity,
moderate conjunctival redness and
chemosis, slight iritis and slight discharge. By 7 days 2 of
the 3 rinsed eyes returned to normal and the remain showed
complete recovery by 11 days post-instillation.

Non-rinsed group:
The 6 non-rinsed eyes showed slight corneal opacity, slight 
iritis, moderate to severe conjunctival responses and slight
to severe discharge. By 7 days 4 of the 6 treated eyes
returned to normal and the remaining 2 eyes showed complete
recovery by 9-10 days post-instillation.

Interpretation of results:
Category II
Conclusions:
Under the experimental conditions described in this study report the substance was considered as moderately irritant when administered by ocular route in rabbits.
Executive summary:

This study was conducted according test guideline EPA OPP 81 -4. MMB was applied to one eye of 3 New Zealand White rabbits and to one eye of 6 New Zealand White rabbits. Reading of the eye scores were made on the day of treatment after 1 hour, and after 24 hrs, 48 hrs and 72 hrs after instillation and on 7, 9 and 10 day until reversibility. Mean scores of 24, 48 and 72 h readings for the rinsed group animal 1/animal 2/animal 3 were for corneal opacity 1/0/0.33, iritis 0.66/0.66/0.66, conjunctiva redness 2/1.66/1.66 and conjunctiva chemosis 2/2/1.33; for the non-rinsed group readings for animal 1/animal 2/animal 3/animal 4/animal 5/animal 6 were for corneal opacity 0.33/1/0/0/0.33/0, iritis 1/1/1/1/1/0.33, conjunctiva redness 2/2.33/1.66/1.66/1.33/1.66 and conjunctiva chemosis 1.33/1.33/1.33/1.33/1.33/1.33. Corneal opacity, iritis, conjunctiva redness and conjunctiva chemosis were fully reversible by 11 days for the rinsed-group and 10 days for the non-rinsed group.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

In a key study with an occlusive application of MMB on 6 New Zealand white rabbits for 4 hours ( J.A. Cuthbert (1991)), only a very slight erythema was noted at one test site on day 1 and the reaction had resolved by day 2. Mean irritation scores were calculated to be 0.04 (Solfit - 100%) and 0.00 (Solfit - 50% v/v in distilled water). It is concluded that the test material is non-irritant to rabbit skin under the test conditions. In a supporting study with an occlusive application of MMB for 28 consecutive 23 h exposures on 6 New Zealand rabbits ( J.A. Cuthbert; D. Jackson (1991)) mean irritation scores were calculated to be 0.6 (Solfit - 100%) and 0.00 (Solfit - 50% v/v in distilled water). All reactions had resolved on day 23. In this 28 day repeat skin application study of the pure substance indicated that MMB is only slightly irritating to the skin. The photoirritation potential of the substance was investigated in guinea pigs. Solfit was applied dermally at concentrations of 100%, 50%, 25% and 10% v/v in distilled water to test and control groups followed by exposure to UVA in the test group only. No photoirritant responses were noted in the test group.

MMB was also tested for eye irritation in an in vivo test in rabbits (according to EPA OPP 81 -4 and GLP). Three rabbits had Solfit installed into the right eye which was then rinsed 30 -60 s later with circa 100 ml of distilled water. The 3 rinsed eyes showed slight to moderate corneal opacity, moderate conjunctival responses, slight iritis and slight discharge. By 7 days 2 of the 3 rinsed eyes had returned to normal and the third showed complete recovery by 11 days post instillation. A further six rabbits had Solfit instilled into the right eye but were not subjected to rinsing. The 6 non-rinsed eyes showed slight corneal opacity, slight iritis, moderate to severe conjunctival responses and slight to severe discharge. By 7 days 4 of the 6 treated eyes had returned to normal and the remaining 2 showed complete recovery by 9 -10 days post instillation. It is concluded that the substance is moderately irritant to rabbit eyes, however rinsing 30 -60 s after instillation with distilled water slightly reduces the irritation potential of the substance.


Justification for selection of skin irritation / corrosion endpoint:
The 1991 Inveresk (J.A. Cuthbert, 1991) study on skin irritation was conducted following a recognized study guideline. In this test the substance was determined to be not irritating. In addition no clinical signs where observed in a reliable acute toxicity test (Section 5.2.1; J.A. Cuthbert; D. Jackson, 1991) with a dermal application route up to the highest tested concentration of 2000 mg/kg. In a subacute irritation study the dermal irritation potential of the substance was tested. The test material was applied at concentrations of 100% and 50% v/v in distilled water. Treatment comprised 28 consecutive 23h exposure with skin assessment 1h after patch removal. No skin reactions were noted following repeat application at the concentration of 50% v/v in distilled water. Skin reactions were observed at the concentration of 100%. The mean score of each of the six test animals in this test group was <1 and all observed reactions were reversible during further application periods until the end of the test. Due to the determined skin reactions, the substance was found slightly irritating at 100% under subacute test conditions. However, according to regulation EC No 1272/2008 the substance was not considered irritating.

Effects on eye irritation: irritating

Justification for classification or non-classification

Based on the results of test data, MMB is not irritating to the skin following criteria under 67/548/EEC and CLP Regulation (EC) No. 1272/2008.

According to the mean scores observed for conjunctiva redness (non-rinsed group), the substance is considered to be irritating to the eyes (H319, causes severe eye irritation; Cat. 2 according to CLP and R36, irritating to eyes according to 67/548/EEC.