Salicylamide

Endpoint summary

Description of key information

Skin: Not corrosive, EpiDerm, EU method B40, Dreher 2010
Skin: Not irritant, EpiSkin, EU method B46, Dreher 2010
Skin: Not irritant, rabbit, Berner 1989
Eye: Not severe irritant, OECD 437, Dreher 2010
Eye: Non-irritating, EpiOcular, Stern 1998
Eye: Non-irritating, draize, 24h maximum average score, Stern 1998

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 May 2010 - 10 May 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, no restrictions, fully adequate for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: B46 of Council Regulation (EC) No 761/2009

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Species:

other: in vitro using EpiSkin inserts (3-dimensional human skin model, comprising a reconstructed epidermis with a functional stratum corneum, supplied by SkinEthic Laboratories, Nice, France)

Strain:

other: not applicable

Type of coverage:

other: not applicable

Preparation of test site:

other: not applicable

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable

Amount / concentration applied:

25 mg

Duration of treatment / exposure:

15 minutes

Observation period:

not applicable

Number of animals:

not applicable

Irritation / corrosion parameter:

other: other: viability of tissues

Value:

98.1

Remarks on result:

other:

Remarks:

Time point: 15 min treatment. (migrated information)

Based on the cell viability measurements obtained, the following mean viability measurements for the test article, negative control and positive control were calculated to be: 98.1%, 100% and 7.9% respectively.

 

These results indicate the viability of the epidermal tissue was not reduced to below 50% of the negative control and therefore may be considered to be non-irritant. The positive control showed an appropriate response in the assay system.

 

No other test substance related effects were observed.

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The substance was not irritant to the in vitro skin model EpiSkin.

Executive summary:

In order to assess the in vitro skin irritation potential of salicylamide, EpiSkin inserts were treated with the substance, negative control (phosphate buffered saline (PBS)) and positive control (5% v/v sodium dodecyl sulphate (SDS)) for 15 minutes. At the end of the treatment period, the tissues were washed with PBS and cell viability was assessed using the MTT (3-(4, 5-Dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium bromide, also known as Thiazolyl blue) interacting substances assay. The skin irritation potential was classified according to the remaining cell viability obtained after test article treatment.  

The group mean viability for the test article was 98.1%, for the negative control was 100% and for the positive control was 7.9%.

Salicylamide was not irritant to the in vitro skin model EpiSkin.

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 April 2010 - 30 April 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, no restrictions, fully adequate for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD 431

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Species:

other: in vitro using EpiDerm inserts (3-dimensional human skin model, comprising a reconstructed epidermis with a functional stratum corneum, supplied by MatTek Corporation, Ashland, Massachusetts, USA)

Strain:

other: not applicable

Type of coverage:

other: not applicable

Preparation of test site:

other: not applicable

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable

Amount / concentration applied:

25 mg

Duration of treatment / exposure:

3 minutes and 1 hour

Observation period:

not applicable

Number of animals:

not applicable

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

experiment 1

Value:

96

Remarks on result:

other: 3 minute treatment

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

experiment 2

Value:

101

Remarks on result:

other: 3 minute treatment

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

experiment 1

Value:

94

Remarks on result:

other: 1 hour treatment

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

experiment 2

Value:

102

Remarks on result:

other: 1 hour treatment

3 minute: The viability of the tissues was 96% and 101% in experiments 1 and 2, respectively. The viability of tissues treated with the positive control was 37% and 24% confirming appropriate performance of the assay.

 

1 hour: The viability of the tissues was 94% and 101% in experiments 1 and 2, respectively. The viability of tissues treated with the positive control was 20% and 14% confirming appropriate performance of the assay.

 

No other test substance treatment related effects were observed.

Interpretation of results:

other: non corrosive

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The substance was not corrosive to the in vitro skin model EpiDerm.

Executive summary:

In order to assess the in vitro skin corrosivity potential of salicylamide, duplicate EpiDerm inserts were treated with the substance, distilled water (negative control) and 8N potassium hydroxide (positive control) for 3 minutes and 1 hour. At the end of the treatment period, the tissues were washed with phosphate buffered saline (PBS) and cell viability was assessed using the MTT (3-(4, 5-Dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium bromide, also known as Thiazolyl blue) assay. The skin corrosivity potential was classified according to the remaining cell viability obtained after test material treatment with either of the two treatment times.

The viability of the tissues following a 3 minute treatment was 96% and 101% in experiments 1 and 2, respectively.

The viability of the tissues following a 1 hour treatment was 94% and 102% in experiments 1 and 2, respectively.

The positive control gave appropriate responses indicating the correct performance of the assay.

Salicylamide was not corrosive to the in vitro skin model EpiDerm.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 June 2010 - 17 June 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, no restrictions, fully adequate for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD 437 (adopted 7 September 2009)

Deviations:

no

Principles of method if other than guideline:

not applicable

GLP compliance:

yes

Species:

other: in vitro study using excised bovine corneas

Strain:

other: not applicable

Details on test animals or tissues and environmental conditions:

not applicable

Vehicle:

other: 0.9% sodium chloride solution

Controls:

other: 3 corneas used with negative control (0.9% sodium chloride solution) and 3 with a positive control (20% w/v imidazole).

Amount / concentration applied:

750 µL

Duration of treatment / exposure:

Assessment of corrosivity/severe irritation: 4 hour incubation. Permeability endpoint additional incubation for 1.5 hours ± 5 minutes

Observation period (in vivo):

not applicable

Number of animals or in vitro replicates:

3 corneas per treatment (test, positive and negative control)

Irritation parameter:

in vitro irritation score

Value:

24.69

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other: did not cause corrosion or severe irritation

Corneal opacity, permeability and in vitro irritation scores

Chemical	mean corneal opacity	Permeability		IVS score
		mean negative control corrected optical density	average group corrected optical density
test substance	-1.7	n/a	1.7593	24.69
negative control	0.0	0.0240	0.0000	0.00
positive control	72.7	n/a	-0.0053	72.62

Interpretation of results:

other: does not cause corrosion or severe irritation

Remarks:

Criteria used for interpretation of results: other: OECD

Conclusions:

The substance was considered not to cause corrosion or severe irritation to the eye under the conditions of the assay.

Executive summary:

A volume of 750 µL of salicylamide formulation, negative control (0.9% sodium chloride solution) or positive control (20% w/v imidazole) was applied to each of three excised bovine corneas followed by a 4 hour incubation at 32°C. After this incubation, each cornea was washed with media containing phenol red followed by media without phenol red, the opacities measured and then the anterior chamber emptied. For the permeability endpoint, sodium fluorescein solution was added into the anterior chamber and the corneas were incubated in the vertical position for 1.5 hours ± 5 minutes. Following this period, the media in the posterior chamber was removed and three 200 μL aliquots of this media (per cornea) were analysed for optical density at 490 nanometers.

The salicylamide formulation produced an In Vitro Irritation Score of 24.69.

The positive control article produced an In Vitro Irritation Score of 72.62.

Salicylamide was considered not to cause corrosion or severe irritation to the eye under the conditions of the assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Irritation/Corrosion

In Vitro Data

Two in vitro studies are available, both done according to GLP, using guideline methods which are validated for regulatory use according to ECVAM.

 

In order to assess the in vitro skin corrosivity potential of salicylamide, duplicate EpiDerm inserts were treated with the substance, distilled water (negative control) and 8N potassium hydroxide (positive control) for 3 minutes and 1 hour. The skin corrosivity potential was classified according to the remaining cell viability obtained after test material treatment with either of the two treatment times. The viability of the tissues following a 3 minute treatment was 96% and 101% in experiments 1 and 2, respectively. The viability of the tissues following a 1 hour treatment was 94% and 102% in experiments 1 and 2, respectively. The positive control gave appropriate responses indicating the correct performance of the assay. Salicylamide was not corrosive to the in vitro skin model EpiDerm.

In order to assess the in vitro skin irritation potential of salicylamide, EpiSkin inserts were treated with the substance, negative control (phosphate buffered saline (PBS)) and positive control (5% v/v sodium dodecyl sulphate (SDS)) for 15 minutes. The skin irritation potential was classified according to the remaining cell viability obtained after test article treatment. The group mean viability for the test article was 98.1%, for the negative control was 100% and for the positive control was 7.9%. Salicylamide was not irritant to the in vitro skin model EpiSkin.

In Vivo Data

No data with an identifiable/validated source were identified. Berner (1989) makes reference to salicylamide being non-irritant in studies with rabbits. No details were given.

 

Human Data

Skin irritation in human female volunteers was assessed before and after 1-day exposure to test substance-loaded hydrogel discs, and again 24 hours later, by assessment of erythema, edema, blood flow (by laser Doppler velocimetry), color, and primary irritation index (Berner 1990).

Hydroxyethyl methacrylate (HEMA) hydrogel films were prepared by polymerization from HEMA, carefully extracted to remove free monomer, and cut into 1 cm2 discs, which were loaded with the test substance by soaking in a saturated solution in ethanol/water (7:3) and dried. Immediately before application, discs were soaked in a saturated aqueous solution of the test material, and applied to the scapular region of the test subjects. The loaded test discs were occluded with an ethylene vinyl acetate membrane and secured with tape. The loading of the discs was determined by the weight difference of the disc before and after. The concentration was checked by extraction into a known volume of ethanol/water and analysis. Percent uptake per dry weight: 36.6 +- 5.9.

Under the conditions of the study, human volunteers treated with salicylamide were not significantly different from a water control in any of the observed variables.

Eye Irritation

In Vitro Data

An in-vitro study was reported using the non-validated EpiOcular method (Stern 1998). Normal human-derived epidermal keratinocytes cultured to form a stratified squamous epithelium (EpiOcular) were exposed to the test substance, and cell viability was assessed by incubation with MTT (3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide). Under the EpiOcular criteria, the substance tested non-irritating to the eyes.

 

A validated in vitro method, conducted according to GLP and OECD 437 guidelines, was conducted (Dreher 2010). A volume of salicylamide formulation, negative control (0.9% sodium chloride solution) or positive control (20% w/v imidazole) was applied to each of three excised bovine corneas followed by a 4-hour incubation at 32°C. After this incubation, each cornea was washed with media containing phenol red followed by media without phenol red, the opacities measured and then the anterior chamber emptied. For the permeability endpoint, sodium fluorescein solution was added into the anterior chamber and the corneas were incubated in the vertical position for 1.5 hours ± 5 minutes. Following this period, the media in the posterior chamber was removed and three 200 μL aliquots per cornea were analysed for optical density. The salicylamide formulation produced an in vitro Irritation Score of 24.69. The positive control article produced an In Vitro Irritation Score of 72.62. Salicylamide was considered not to cause corrosion or severe irritation to the eye under the conditions of the assay.

 

In Vivo Data

Stern (1998) reported the result that salicylamide as being non-irritating to the eye (based on 24-hour maximum average score MAS) in a Draize test conducted prior to 1989. The original data were not published.

Justification for selection of skin irritation / corrosion endpoint:
GLP compliant, guideline study, no restrictions, fully adequate for assessment

Justification for selection of eye irritation endpoint:
GLP compliant, guideline study, no restrictions, fully adequate for assessment

Justification for classification or non-classification

Skin Irritation/Corrosion

Results from validated in vitro studies for skin corrosion and irritation, conducted according to Regulation (EC) No. 440/2008 and 761/2009, demonstrated the substance to be non-corrosive and non-irritating to skin. The EpiSkin, B46 test method states that it was prevalidated, optimised, and validated against irritant data based around the EU classification R38. Studies in human volunteers, and a unverifiable result in rabbits, also indicated no irritating effects. As a result, the substance is not considered to be classified under Directive 2001/59/EEC, and the result is conclusive.

 

Results from validated in vitro studies for skin corrosion and irritation, conducted according to Regulation (EC) No. 440/2008 and 761/2009, demonstrated the substance to be non-corrosive and non-irritating to skin. The EpiSkin, B46 method has been demonstrated to be valid for discriminating between EU GHS Category 2 (H315) and non-irritants, but not between UN GHS Category 3 and non-irritants (comment by ECVAM). Studies in human volunteers, and a unverifiable result in rabbits, also indicated no irritating effects. As a result, the data are considered conclusive and the substance is not classified for skin irritation, according to Regulation (EC) No. 1272/2008.

 

Eye Irritation

Two in vitro tests for eye irritation are available, one validated (OECD 437) and one currently unvalidated (EpiOcular). Both results were negative. ECVAM have commented that OECD 437 should only be used to identify corrosive or severe irritants. One negative, but unverifiable in vivo result from a Draize test was also available. Based on the available information the substance is considered to be not classified for R41, Risk of serious damage to eyes, and inconclusive as not classified as R36, Irritating to eyes.

 

Two in vitro tests for eye irritation are available, one validated (OECD 437) and one currently unvalidated (EpiOcular). Both results were negative. ECVAM have commented that OECD 437 should only be used to identify corrosive or severe irritants. One negative, but unverifiable in vivo result from a Draize test was also available. Based on the available information the substance is considered to be not classified for Serious eye damage, Category 1 (H318), and inconclusive as not classified as Irritating to eyes, Category 2 (H319), according to Regulation (EC) No. 1272/2008.