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Administrative data

Description of key information

Xanthan lyase was not tested for skin and eye irritation, but pectate lyase a closely related enzyme belonging to the same enzyme sub-subclass i.e. 4.2.2 was tested for skin and eye irritation in vivo. Due to the similarity of the two enzymes with regard to their catalytic activity, similar results are expected for xanthan lyase.

Pectate lyase was tested for skin and eye irritation in rabbits.

- There were no erythema or edema noted at any of the readings of the dermal reactions in treating rabbit skin (2.5 x 2.5 cm) with pectate lyase for 4 hours. Therefore, pectate lyase should not be classified as an irritant.

- No corneal opacity, iris reactions or tear secretion were noted at any time during the test. Slight conjunctival reaction and chemosis were observed earlier on. However, all signs were reversible, and no reactions were seen after 48 or 72 hours. The rabbits showed no signs of systemic reaction to the treatment.

In conclusion, pectate lyase can be classified as a ‘non irritant’ to the eye.

Based on the results from pectate lyase, xanthan lyase is not irritant to the skin and not irritant to the eye.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Referenceopen allclose all

Endpoint:
skin irritation: in vitro / ex vivo
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
an in vitro skin irritation study does not need to be conducted because adequate data from an in vivo skin irritation study are available
Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 1999-02-15 to 1999-05-05
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
Both enzymes belonging to the same enzyme sub-subclass i.e 4.2.2 and have similar catalytic activity, thus read-across from pectate lyase to xanthan lyase can be applied.
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Version / remarks:
1992
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: EEC
Version / remarks:
EEC (1992) Acute Toxicity (Skin irritation). Section B4 (L383A/124-L383A/127) of the Annex to
the European Communities Directive 92/69/EEC. The Official Journal of the European communities
L383A (vol. 35), 29 December 1992 (ISSN 0378-6978).
Deviations:
no
Principles of method if other than guideline:
During acclimatisation and experimental period the weight of two of the animals was up to 1/2 kg less than aimed in protocol. This was due to reduced water intake of especially rabbit No. 6 during the acclimatisation period. When the rabbits were offered water in a bowl the weight of rabbit No. 6 increased by 1/2 kg within three days. As the skin of all rabbits tested were without signs of dehydration this deviation from protocol are not considered to have had any influence on the conclusion of the study.
GLP compliance:
yes
Species:
rabbit
Strain:
other: Danish Landrace, albino
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Bred by Statens Seruminstitut "Hvidesten", Denmark
- Weight at study initiation: between 2.08 - 2.56 kg
- Age at study initiation: Young adults
- Housing: Individually, in animal room with control of temperature (20±3°C) and humidity (30-70%)
- Diet: 110 g standard diet per day (Altromin 2110, Standard Diet for Rabbits) ad libitum
- Water: Tap water ad libitum
- Acclimation period: 8 days for animal no. 1 and 3 and 14 days for animal no. 6
- Photoperiod (hrs dark / hrs light): 12 hrs/12hrs

IN-LIFE DATES:
From: 1999-02-22 To: 1999-03-05
Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): undiluted
Duration of treatment / exposure:
4 hours
Observation period:
0.5-1, 24, 48, 72 hrs
Number of animals:
3
Details on study design:
The test compound Pectate Lyase was assessed by semiocclusive application of 0.5 mL of the test material formulation to an area of 2.5 x 2.5 cm on the closel clipped flank of three male albino rabbits for 4 hrs.
The study was conducted to comply with the following guidelines:
- Organisation for Economic Co-operation and Development (OECD) test guideline 404.

TEST SITE
- Area of exposure: 2.5 x 2.5 cm
- Type of wrap if used: gauze patch and plaster

REMOVAL OF TEST SUBSTANCE
- Washing: Washed with water

OBSERVATION TIME POINTS
0.5-1, 24, 48, 72 hrs

SCORING SYSTEM:
- Method of calculation:
Erythema and eschar formation Grade
No erythema ...................................................................................................................................0
Very slight erythema (barely perceptible) ......................................................................................1
Defined erythema ............................................................................................................................2
Moderate to severe erythema .........................................................................................................3
Severe erythema (beet redness) to slight eschar formations (injuries in depth) ...........................4

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 mm) ...............................................................................3
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
edema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
edema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
erythema score
Basis:
animal #6
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
edema score
Basis:
animal #6
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritant / corrosive response data:
No erythema, eschar formation or oedema was observed at the test sites at any of the six rabbits at the examinations 1, 24, 48 or 72 hours after termination of exposure.
Two rabbits showed skin reaction related to the outer rim of the application area where the skin was exposed to both plaster and test material. This is not considered as an effect related to irritative properties of the test material.
Other effects:
No other effects.
Interpretation of results:
GHS criteria not met
Conclusions:
There were no erythema or edema noted at any of the readings of the dermal reactions in treating rabbit skin (2.5 x 2.5 cm) with pectate lyase for 4 hours. Therefore, pectate lyase should not be classified as an irritant.
Executive summary:

The acute dermal irritant effect of pectate lyase was investigated according to the method recommended in the OECD Guideline No 404, “Acute Dermal Irritation/Corrosion”. The study was conducted in accordance with GLP. The study was performed on three male albino rabbits, Danish Landrace. They were each exposed to 0.5 mL of the undiluted liquid test item applied under semiocclusive conditions to each of three closely-clipped test sites, 2.5 x 2.5 cm. After a 4-hour exposure period, the test item was removed from the test site and the skin was examined.

Dermal reactions were scored at 0.5-1, 24, 48 and 72 hours after patch removal. There were no erythema or edema noted at any of the readings of the dermal reactions.

Under the conditions of this test and criteria of the EEC Directive, pectate lyase should not be classified.

Endpoint:
skin irritation / corrosion, other
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
other information
Justification for type of information:
Read-across to pectate lyase is applied. Data on pectate lyase are considered also to be valid for xanthan lyase, because both enzymes belong to the same enzyme sub-subclass IUB 4.2.2 and are considered to have a similar toxicological profile also with regard to irritation.
Reason / purpose for cross-reference:
read-across source
Interpretation of results:
GHS criteria not met
Conclusions:
Based on read-across data from pectate lyase (IUB 4.2.2.2), it can be concluded that xanthan lyase is not irritating to the skin.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Referenceopen allclose all

Endpoint:
eye irritation: in vitro / ex vivo
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
an in vitro eye irritation study does not need to be conducted because adequate data from an in vivo eye irritation study are available
Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 1999-02-15 to 1999-05-05
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
Both enzymes belonging to the same enzyme sub-subclass i.e 4.2.2 and have similar catalytic activity, thus read-across from pectate lyase to xanthan lyase can be applied.
Qualifier:
according to guideline
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Version / remarks:
1992
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: EEC
Version / remarks:
EEC (1992). Acute Toxicity (Eye irritation). Section B5 (L383A/127-L383A/130) of the Annex to
the European Communities Commision Directive 92/69/EEC. The Official Journal of the European
Communities L.383A ( Vol. 35), 29 December 1992 (ISBN 0378-6978).
Deviations:
no
GLP compliance:
yes
Species:
rabbit
Strain:
other: Danish Landrace, albino
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: Bred by Statens Seruminstitut "Hvidesten", Denmark
- Weight at study initiation: between 2.14 - 2.56 kg
- Age at study initiation: Young adults
- Housing: Individually, in animal room with control of temperature (20±3°C) and humidity (30-70%)
- Diet: 110 g standard diet per day (Altromin 2110, Standard diet for rabbits) ad libitum
- Water: Tap water ad libitum
- Acclimation period: 14 days
- Photoperiod (hrs dark / hrs light): 12 hrs/12hrs

IN-LIFE DATES:
From: 1999-02-22 To: 1999-03-12
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
Test batch used as is.
- Amount(s) applied (volume or weight with unit): 0.1 mL into the left eye
Duration of treatment / exposure:
The test material was applied to the conjunctival sac. The lids were gently held together for approximately 1 second. The untreated eye served as a control.
Observation period (in vivo):
The reactions were judged 1, 24, 48 and 72 hours after instillation of the test material.
Number of animals or in vitro replicates:
3 male rabbits
Details on study design:
REMOVAL OF TEST SUBSTANCE
- Washing: Not specified
SCORING SYSTEM: The ocular reactions were recorded at 1, 24, 48 and 72 hours after instillation according to the guideline.
Irritation parameter:
conjunctivae score
Remarks:
(redness)
Basis:
animal: #2, #4
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
conjunctivae score
Remarks:
(redness)
Basis:
animal #5
Time point:
24/48/72 h
Score:
0.3
Max. score:
1
Reversibility:
fully reversible
Irritation parameter:
chemosis score
Basis:
animal: #2, #4, #5
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
cornea opacity score
Basis:
animal: #2, #4, #5
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
iris score
Basis:
animal: #2, #4, #5
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
other: Tear secretion
Basis:
animal: #2, #4, #5
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritant / corrosive response data:
No corneal opacity, iris reactions or tear secretion were noted at any time during the test. Conjunctiva! reaction (redness, score 1) was observed in two rabbits at the 1 hour reading and in one rabbit at the 24 hour reading. Chemosis (score 1) was observed at the 1 hour reading in two animals. All signs were reversible, and no reactions were seen after 48 or 72 hours. The rabbits showed no signs of systemic reaction to the treatment.
Other effects:
None
Interpretation of results:
GHS criteria not met
Conclusions:
No corneal opacity, iris reactions or tear secretion were noted at any time during the test. Slight conjunctival reaction and chemosis were observed earlier on. However, all signs were reversible, and no reactions were seen after 48 or 72 hours. The rabbits showed no signs of systemic reaction to the treatment.
In conclusion, pectate lyase can be classified as a ‘non irritant’ to the eye.
Executive summary:

In accordance with the OECD guideline 405, a test for eye irritation in rabbits was performed with pectate lyase, batch PPE 6345.

The eyes of three animals were checked for irritation before instillation and only healthy animals were used. 0.5 mL of pectate lyase, batch PPE 6345 was placed in the conjunctival sac of the left eye by pulling the lower eyelid away from the eyeball. The lids were gently held together for about one second after instillation. The untreated eye served as control. The ocular reactions were recorded at 1, 24, 48 and 72 hours after instillation according to the specified guideline.

No corneal opacity, iris reactions or tear secretion were noted at any time during the test. Conjunctival reaction (redness, score 1) was observed in two rabbits at the 1 hour reading and in one rabbit at the 24 hour reading. Chemosis (score 1) was observed at the 1 hour reading in two animals. All signs were reversible, and no reactions were seen after 48 or 72 hours. The rabbits showed no signs of systemic reaction to the treatment.

In conclusion, pectate lyase can be classified as a 'non-irritant' to the rabbit eye.

Endpoint:
eye irritation, other
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
other information
Justification for type of information:
Read-across to pectate lyase is applied. Data on pectate lyase are considered also to be valid for xanthan lyase, because both enzymes belong to the same enzyme sub-subclass IUB 4.2.2 and are considered to have a similar toxicological profile also with regard to eye irritation.
Reason / purpose for cross-reference:
read-across source
Interpretation of results:
GHS criteria not met
Conclusions:
Based on the read-across from in vivo eye irritation with pectate lyase, IUB 4.2.2.2 xanthan lyase is not irritating to the eye.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Justification for classification or non-classification

Based on the results of skin and eye irritation tests, xanthan lyase cannot be classified.