Mannanase, endo-1,4-β-

Endpoint summary

Description of key information

Mannanase is neither a skin nor an eye irritant.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin corrosion: 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

Reference 2

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 5, 2002 – November 8, 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Animals were procured from Millbrook Breeding Labs, Amherst MA 10/23/02. Three healthy animals were selected after an equilibration period of at least five days. The test animals were born the week of August 4th, 2002 and pre-test body weights ranged from 2.3 to 2.5 kg.

Animals were identified by cage notation and metal ear tags. Animals were each housed in a separate suspended wire cage. Bedding was placed beneath each cage and changed at least three times per week. Fresh food (PMI Rabbit Chow Diet #5321) was provided daily. Water was freely available at all times. The animal room was used only for actue testing on rabbits. The room was temperature and humidity controlled, had a 12 hour light/dark cycle, and was kept clean and vermin free.

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Remarks:

The test article was used as received.

Controls:

no

Amount / concentration applied:

The test article was dosed by volume at 0.5 mL per rabbit.

Duration of treatment / exposure:

The test area was covered with a 4 ply surgical gauze patch and the torso was wrapped with plastic in a semi-occlusive manner and secured with non-irritating tape. The test article was kept in contact with the skin for 4 hours, at which time the wrappings were removed.

Observation period:

Observation of any dermal reactions were recorded at 1, 24, 48 and 72 hours after patch removal. The skin was also evaluated for ulceration and necrosis or any evidence of tissue destruction.

Number of animals:

Three (two males and one female)

Details on study design:

The dorsal area of the trunk of each animal was clipped free of hair on the day prior to the application of the test article. The site of administration was approximately 2.5 cm x 2.5 cm. The test article was dosed by volume at 0.5 mL per rabbit. The test area was covered with a 4 ply surgical gauze patch and the torso was wrapped with plastic in a semi-occlusive manner and secured with non-irritating tape. The test article was kept in contact with the skin for 4 hours, at which time the wrappings were removed. Observation of any dermal reactions were recorded at 1, 24, 48 and 72 hours after patch removal. Residual test article was removed from the test site by gentle washing with distilled water prior to scoring observations.

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Reversibility:

other: Not applicable. No erythema observed.

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Reversibility:

other: Not applicable. No erythema observed.

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Reversibility:

other: Not applicable. No erythema observed.

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Reversibility:

other: Not applicable. No edema observed.

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Reversibility:

other: Not applicable. No edema observed.

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Reversibility:

other: Not applicable. No edema observed.

Irritant / corrosive response data:

There were no erythema or edema noted. There were no overt signs of systemic toxicity. The Primary Irritation Score was determined to be 0.

Other effects:

None.

Systemic observations were also made at 1, 24, 48, and 72 hours after patch removal. All observations were normal at all time points in all test animals. There were no abnormal clinical signs observed and all body weight changes were normal.

Interpretation of results:

GHS criteria not met

Conclusions:

The test article is not irritating to skin. Mannanase shall be classified as 'Non Irritant'.

Executive summary:

Three New Zealand White rabbits (2 males : 1 female) were used. The test article (0.5 mL) was applied to one intact dermal site/rabbit. The test article was kept in contact with the skin for 4 hours, at which time the wrappings were removed. Dermal reactions were scored at 1, 24, 48 and 72 hours after patch removal. There were no erythema or edema noted at any time during the study period. There were no overt signs of systemic toxicity. The Primary Irritation Score was determined to be 0 and mannanase shall be classified as 'Non Irritant'.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 November 2002 - 07 November 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

The animals were supplied by Millbrook Breeding Labs, Amherst, MA.
The animals were born 08/04/2002. The pre-test body weight range was 2.4-2.6 kg. They were housed 1 per cage in suspended cages. The animal room was temperature controlled and had a 12-hour light/dark cycle.

Vehicle:

unchanged (no vehicle)

Controls:

other: One eye was dosed, while the other served as control.

Amount / concentration applied:

0.1 mL

Duration of treatment / exposure:

After instillation, the eyelids were held together for approximately one second.

Observation period (in vivo):

The treated eye of each rabbit was examined for irritation of the cornea, iris and conjunctiva at 1, 24, 48 and 72 hours.

Number of animals or in vitro replicates:

2 male and 1 female rabbit

Details on study design:

Scoring was done according to the Draize technique and OECD TG 405.
The eyes were not washed. Sodium fluorescein dye procedure was used at the 24-hour observation period.
A mini-Maglite flashlight with high intensity bulb was used for the examination.

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 48 hrs

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other:

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

There was no corneal opacity or iritis noted at any observation period. As to conjunctival irritation, the following was noted: At the 1 hour reading, slight conjunctival effects in the form of redness, chemosis and discharge were present (score 1 for all parameters) in rabbit # 1, 2 and 3. In two animals this effect had disappeared at the following observations (24, 48 and 72 hours after treatment). At the examination at 24 hours after exposure, slight redness (score 1) without any swelling of the conjunctiva or any discharge remained in one of the three rabbits. All eye effects had cleared completely at the following observations, 48 and 72 hours after treatment.

Interpretation of results:

GHS criteria not met

Conclusions:

Mannanase is not classified as an eye irritant.

Executive summary:

Three New Zealand White rabbits (2 males : 1 female) were used. 0.1 mL of mannanase was placed into the conjunctival sac of one eye of each rabbit. The eyes were examined and scored at 1, 24, 48 and 72 hours after dosing using Draize techniques. Sodium fluorescein dye procedure was used at the 24-hour observation period. The untreated eye served as control. No corneal opacity was noted at any scoring period. Slight conjuctival irritation was observed, but this cleared within 48 hours. The Primary Irritation Score was determined to be less than 1 and mannanase shall be classified as 'Non Irritant'. 

 

GHS Classification: Not Classified

Reference 2

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 conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

The skin and eye irritation potential of mannanase has been tested according to OECD guidelines, in compliance with GLP. No effects were seen at all in the skin irritation study. Only transient conjunctival reactions were seen in the eye irritation study. All findings were fully reversible within 48 hrs.

The conclusion was that mannanase is neither a skin nor an eye irritant.

Justification for classification or non-classification

The skin and eye irritation potential of mannanase has been tested according to OECD guidelines and in compliance with GLP. The conclusion was that mannanase did not exert any skin and eye irritation and therefore should not be classified.