2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone

Endpoint summary

Description of key information

Skin Irritation
Based on the observed results and applying the evaluation criteria it was concluded, that Pigment Yellow 101 (chemical name: 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone, CAS No 2387-03-3) does not show a skin irritation potential in the human EpiDermTM skin irritation test under the test conditions chosen. The chemical was also not found to be irritating to the skin of rabbit.
Eye Irritation
Test substance Lumogen LT light yellow (chemical name: 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone, CAS No 2387-03-3) was found to be not irritating to the eye of rabbit after 8 days observation period.

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Data is from BASF study reports

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Principles of method if other than guideline:

The objective was to assess the potential for skin irritation of the test material upon first contact with skin. The assessment of the skin irritation potential is included in international regulatory requirements for the testing of chemicals. Due to animal welfare reasons skin irritation was determined using the reconstructed human epidermal model EpiDermTM.The present test is based on the experience that irritant chemicals produce cytotoxicity in human reconstructed epidermis after a 1-hour topical exposure and about 42 hours postincubation.The test is designed to predict skin irritation potential of a chemical by using the three dimensional human epidermis model EpiDermTM. After application of the test material to the stratum corneum surface of the EpiDermTM tissue the induced cytotoxicity (=loss of viability) is measured by a colorimetric assay. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity. The mitochondrial dehydrogenase reduces the yellow colored water-soluble 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) to the insoluble blue colored formazan. After isopropanol extraction of the formazan from the tissue the optical density of the extract is determined spectrophotometrically. Optical density of the extracts of test-item treated tissues is compared to negative control values from tissue treated with PBS and expressed as relative tissue viability.

GLP compliance:

yes

Species:

human

Strain:

other: not applicable

Type of coverage:

other: reconstructed three dimensional human epidermis model (EpiDerm™)

Preparation of test site:

other: incubation

Vehicle:

other: sterile PBS

Controls:

yes

Amount / concentration applied:

25 μL bulk volume (about 8 mg) CONTROLS:Negative control (NC): PBS, sterilePositive control (PC): 5% (w/v) sodium dodecyl sulfate (SDS, Sigma, Germany) in highly de-ionized water, sterile

Duration of treatment / exposure:

1 hour

Observation period:

42 hours

Number of animals:

Three dimensional human epidermis model

Details on study design:

EXPERIMENTAL PROCEDURE:Mesh compatibility:For liquid test items a nylon mesh can be used as a spreading support. However, this was not necessary for the solid test item.Thus no pretest for mesh compatibility was performed.Direct MTT reduction:To assess the ability of the test material to directly reduce MTT a pretest was performed as described below.Approximately 25 μL bulk volume of the test item was added to 0.9 mL of the MTT solution.The mixture was incubated in the dark at about 37 °C for 55 to 65 minutes. A negative control (50 μL of highly de-ionized water) was tested concurrently. If the MTT solution color or, in case of water-insoluble test items the border to the waterphase,turned blue / purple, the test item was presumed to directly reduce MTT.The direct reduction of MTT by a test item interferes with the color density produced by metabolic capacity of the tissue and would falsify the test results.In case that direct MTT reduction occurred and visible residues of the test item remained on the tissues after washing, subsequent testing of killed controls (one freeze-killed control tissue (KC)) was considered. Killed controls are treated with, each, the test article and the negative control, in the same way as described in section “Basic procedure” (3.6.3),additionally.

Irritation parameter:

other: Mean tissue viability(% of negative control)

Basis:

mean

Time point:

other: 42 hrs.

Reversibility:

no data

Remarks on result:

other: > 50 % -non-irritant

FINDINGS:

Test article		tissue 1	tissue 2	tissue 3	mean	SD
NC	mean OD570	1.9402	1.8402	1.8907	1.8903
	viability [% of NC]	102.6	97.3	100.0	100	2.65
01/0031-2	mean OD570	2.0252	1.5387	1.6927	1.7522
	viability [% of NC]	107.1	81.4	89.5	93	13.15
PC	mean OD570	0.1067	0.1237	0.1212	0.1172
	viability [% of NC]	5.6	6.5	6.4	6	0.49

Interpretation of results:

not irritating

Remarks:

Migrated informationCriteria used for interpretation of results: EU

Conclusions:

Based on the observed results and applying the evaluation criteria it was concluded, that Pigment Yellow 101 (chemical name: 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone, CAS No 2387-03-3) does not show a skin irritation potential in the EpiDermTM skin irritation test under the test conditions chosen.

Executive summary:

The potential of Pigment Yellow 101 to cause dermal irritation was assessed by a single topical application of 25 μL bulk volume (about 8 mg) of the test item to a reconstructed three dimensional human epidermis model (EpiDerm™).

Three EpiDerm™ tissue samples were incubated with the test item for 1 hour followed by a 42-hours post-incubation period.

Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/ post-incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as suitable endpoint. The formazan production of the test item treated epidermal tissues is compared to that of negative control tissues. The quotient of both values indicates the relative tissue viability.

The EpiDerm skin irritation test showed the following results:

The test item is not able to reduce MTT directly.

The mean viability of the test-item treated tissues determined after an exposure period of 1 hour with about 42 hours post-incubation was 93%.

Based on the observed results it was concluded, that Pigment Yellow 101 does not show a skin irritation potential in the EpiDerm™ skin irritation test under the test conditions chosen.

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from BASF study report

Qualifier:

according to guideline

Guideline:

other: given below

Principles of method if other than guideline:

The objective was to assess the potential for eye irritation of the test material Lumogen LT light yellow to the mucous membrane of rabbit eye.

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

No details available

Vehicle:

not specified

Controls:

not specified

Amount / concentration applied:

50 mg

Duration of treatment / exposure:

24 hrs.

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

No data

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 1 hr

Reversibility:

not specified

Remarks on result:

other: no irritation observed

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24 hrs.

Reversibility:

not specified

Remarks on result:

other: no irritation observed

Eye irritation (Rabbit)	Finding after 1 hrs.	Finding after 24 hrs.	Finding after 8 days
Application of test material (50 mg) Unchanged	Slightly irritating	Slightly irritating	Not irritating
Comparison substance:Talcum	Slightly irritating	Slightly irritating	Not irritating

Interpretation of results:

not irritating

Remarks:

Migrated informationCriteria used for interpretation of results: EU

Conclusions:

Test substance Lumogen LT light yellow (chemical name: 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone, CAS No 2387-03-3) was found to be not irritating to the eye of rabbit after 8 days observation period.

Executive summary:

When test substance Lumogen LT light yellow at dose concentration of 50 mg applied to the rabbit eyes showed slightly irritation during the exposure period of 1 hr. to 24 hrs.

After 8 days of observation period mucous membrane irritation of the test material on the eye is not stronger than that of the comparison product Talcum.

Thus from overall experimental result it is concluded that the test substance Lumogen LT light yellow consider to be not irritating to the eye of rabbit.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion

Skin Irritation

BASF study report (Report no. 61H0031/012313), 2010:

Based on the observed results and applying the evaluation criteria it was concluded, that Pigment Yellow 101 (chemical name: 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone, CAS No 2387-03-3) does not show a skin irritation potential in the human EpiDermTM skin irritation test under the test conditions chosen. The chemical was also not found to be irritating to the skin of rabbit. BASF study report, 1977: When test substance Lumogen LT light yellow at dose concentration of 50 % aqueous solution applied to the rabbit skin, no irritation effects were observed during the exposure period of 24 hrs. Thus from overall experimental result it is concluded that the test substance Lumogen LT light yellow consider to be not irritating to the skin of rabbit.

In a supporting study on similar substance (CAS no.5384-21-4);

 

In OECD GLP testing laboratory, 2014; The study was performed as per OECD guideline No. 404. Three healthy young adult female rabbits were used for conducting acute dermal irritation study. Body weights were re­corded on day 0 (prior to application) and at termination.

 

Rabbits with good intact skin were selected for the study. The hairs of all the rabbits were clipped at contralateral sites, approximately 24 hours prior to treatment. A dose of0.5 gm of test item moistened with 0.5 ml of distilled water was applied to the skin, over an area of approximately 6 x 6 cm clipped of hair on one side of rabbits. The other untreated side was kept as control area and0.5 ml of distilled water was applied at this site. At the end of 4 hours, the gauze patch was removed and test item application site was wiped with water without altering the integrity of the epidermis. 

 

Initially, the test item was applied to the clipped area of skin of one rabbit. The test site was covered with gauze patch. After 4 hours of exposure in Animal No. 1, there was No erythema and oedema observed at 1,24 and 48 hours observation. Hence the confirmatory test was conducted on additional two rabbits (No. 2 and 3)to confirm the non-irritant nature of the test item.

 

The patch was removed after 4 hours and rabbits were observed for erythema and oedema at 1, 24, 48 and 72 hours after patch removal, evaluated and graded as per draize method.

 

In Animals No. 2 and 3 at 1 hour observation after post patch removal, revealed no erythema and oedema. At 24 and 48 and 72 hours observation animals showed no Erythema and oedema was observed during the observation period.

 

The individual mean score at 24, 48 and 72 hours for Animal Nos. 1, 2 and 3 were 0.00, 0.00, 0.00 and 0.00, 0.00, 0.00, for erythema and oedema formation, respectively.  

 

Hence under the experimental test conditions, it was concluded that 4, 4’-methylenedi-2, 6-xylenol (CAS No. 5384-21-4) was Non-Irritating to the skin of femaleNew Zealand White rabbitsunder the experimental conditions tested and Classified as “Category- Unclassified” as per CLP Regulation.

 

Sustainability Support Services (Europe) AB has letter of access (Study report no. 160, 2013): Based on the result obtained from the study, it can be concluded that the test compound 4, 4’- Methylenedi-2, 6-xylenol is non-irritant to skin of the New Zealand white rabbits. The dermal irritation index score is zero.

 

In another supporting studies on similar substance (CAS no.1948-33-0);

 

Mary Ann Liebert, Inc., Publishers, 1986:

1) Skin irritation study was carried out on humans using Modified Draize-Shelanski-Jordan patch procedure.Test chemical conc. of 0.11% by weight used for the study.Total 55 humans were used for the study. Out of 55 test humans, 49 are females and 6 are males.

The test material was applied under occlusive patches for 24 h every other day for a total of 10 induction patches. After a 13-day non-treatment period, a 48-h challenge patch was applied to the back of each subject. A second 48-h challenge patch was applied 7 days later.The challenge sites were evaluated 48 and 72 h after application.

No skin reactions were observed in any other subject during either induction or challenge phases. Thus the test chemical was evaluated to benon-irritating to test humans.

2) Skin irritation study was carried out on humans using Modified Draize-Shelanski-Jordan patch procedure. Test chemical conc. of 0.15% by weight used for the study.Total 52 humans were used for the study. Out of 52 test humans, 41 are females and 11 are males.

The test material was applied under occlusive patches for 24 h every other day for a total of 10 induction patches. After a 13-day non-treatment period, a 48-h challenge patch was applied to the back of each subject. A second 48-h challenge patch was applied 7 days later. The challenge sites were evaluated 48 and 72 h after application.

No skin reactions were observed in any other subject during either induction or challenge phases. Thus the test chemical was evaluated to benon-irritating to test humans.

3) Skin irritation study was carried out on humans using Modified Draize-Shelanski repeat insult patch test.Test chemical conc. of 0.054% by weight used for the study.Total 110 humans were used for the study. Out of 110 test humans, 92 are females and 18 are males.

 

The test material was applied under occlusive patches to the same skin site for a total of eight 24-h inductions. After a 11-day non-treatment period, a 48-h challenge patch was applied to the induction site. A second 48-h challenge patch was applied following removal of the initial challenge patch. Challenge sites were evaluated immediately and 24 h after patch removal.

 

No skin reactions were observed in any other subject during either induction or challenge phases. Thus the test chemical was evaluated to benon-irritating to test humans.

The dermal irritation potential of test article was determined according to the OECD 439 test guideline followed for this study. The Mean % tissue viability compared to negative control (n=3) of the test substance, 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone [CAS: 2387-03-3] was determined to be 92.8%. Thus, substance 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone [CAS 2387-03-3] was considered to be not irritating to the human skin.

From overall reported skin irritation studies of Yellow 101 and its read-across substances, indicate that test substance is not likely to exhibit irritation effects on to the skin of test animal and can be classified as 'non-hazardous' as per the CLP classification criteria. 

Eye Irritation

BASF study report, 1977:

Test substance Lumogen LT light yellow (chemical name: 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone, CAS No 2387-03-3) was found to be not irritating to the eye of rabbit after 8 days observation period.

In a supporting study (Prediction report, Sustainability Support Services - 2016): The eye irritation potential for C.I. Pigment Yellow 101is estimated using OECD QSAR toolbox version 3.3.The test substance was found to be not-irritating to the rabbit eyes.

In a supporting study on similar substance (CAS no.5384-21-4);

 

In OECD GLP testing laboratory, 2014; The study was performed as per OECD guideline no. 405. Rabbits free from injury of eye were selected for the study. The eyes of all the rabbits were examined 24 hours prior to treatment. One eye of each rabbit served as control and other as treated. Control eye was left untreated whereas; 100 mg of test item was instilled in the other (treated) eye of each rabbit. The eye was observed at 1, 24, 48 and 72 hour after test item instillation. Ophthalmoscope was used for scoring of eye lesions.

 

In the initial test, 100 mg of test item (Pulverized Form)was applied into the conjunctival sac of the left eye of animal no.1 whereas the right eye of the rabbit served as the control. As animal no. 1 showed no ocular lesions a confirmatory test was conducted on additional two rabbits (animal no. 2 and 3); 100 mgof test itemwas instilled into the conjunctival sac of right eye of both the rabbits and left eye served as the control. Ocular lesions were seen in animal no. 2 and 3 at 1 hour observation which recovered at 24 hour.

 

Untreated eye of all the three rabbits was normal throughout the experimental period of 72 hours.

 

The following grading scores were observed in treated eye of tested rabbits.

Observation at 1 hour after instillation of test item revealed: Cornea-No ulceration or opacity in all 3 animals; Area of Opacity-Zero in all the animals; Iris: Normal in all the animals. Conjunctivae -Some blood vessels definitely hyperaemic (injected) was observed in Animal no. 2 and 3; Chemosis: No swelling was observed in all the 3 animals.

 

Observation at 24 hours after instillation of test item revealed: Cornea-No ulceration or opacity in all the animals; Area of Opacity-Zero in all the animals; Iris: Normal in all the animals. Conjunctivae - Blood vessels were found to be normal in all the 3 animals; Chemosis: No swelling was observed in all the 3 animals.

 

At 24 hours observation the rabbits were examined for corneal epithelium cell damage using sodium fluorescein strips and noticed 0 % damage in animal no. 1, 2 and 3.

 

Observation at 48 and 72 hours after instillation of test item revealed: Cornea-No ulceration or opacity in all the animals; Area of Opacity-Zero in all the animals; Iris: Normal in all the animals. Conjunctivae -Blood vessels were normal in all the animals; Chemosis: No swelling was observed in all the animals.

The individual mean score for animal nos. 1, 2 and 3at 24, 48, 72 hours for corneal opacity, iris, conjunctiva and chemosis were found 0.00, 0.00, 0.00, 0.00; 0.00, 0.00, 0.00, 0.00 and 0.00, 0.00, 0.00, 0.00 respectively.

 

Under the experimental conditions tested, eye irritation and reversibility of effects on eyes of rabbits was observed within 72 hours.  Hence under the experimental test conditions,“4, 4’- methylenedi-2, 6-xylenol (CAS NO. - 5384-21-4) is “Non Irritant” to New Zealand White female rabbit eyes and is being classified as “Not Classified” as per CLP Regulation.  

 

Sustainability Support Services (Europe) AB has letter of access (Study report no. 161, 2013): Based on the results obtained from current study, it can be concluded that the test compound 4, 4’-Methylenedi-2, 6-Xylenol is non-irritating to the eyes of New Zealand white rabbit when applied at the dose level of 0.1 gm under the test condition.

The ocular irritation potential of test article was determined according to the OECD 492 test guideline. The mean % tissue viability of 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone [CAS: 2387-03-3] was determined to be 75.1%. Thus, 2-hydroxynaphthalene-1-carbaldehyde [(2-hydroxy-1-naphthyl)methylene]hydrazone [CAS: 2387-03-3] was considered to be not irritating to MatTek EpiOcular Tisssue Model OCL-200.

Thus based on results of various studies of eye irritation, it can be concluded that the test substance Yellow 101 is not an eye irritant.

Justification for selection of skin irritation / corrosion endpoint:
Experimental result using the OECD Guideline 404 (Acute Dermal Irritation / Corrosion). Data purchased from BASF. THus, the result is considered to be reliable without restriction

Justification for selection of eye irritation endpoint:
Experimental result. Data purchased from BASF. Thus, the result is considered to be reliable without restriction

Justification for classification or non-classification

On the basis of the available data of skin and eye irritation studies, the substance Pigment yellow 101 can be considered to be not irritating to skin and eyes as per the CLP criteria.