Reaction mass of N-2-hydroxyethylacetamide and N,O-diacetyl-2-aminoethanol

Endpoint summary

Description of key information

Based on in vitro and in vivo studies results, the test substance is considered to be non-irritating to skin and eyes.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From July 25, 1977 to September 02, 1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

other: generally accepted scientific principles and well documented study details, acceptable for assessment

Deviations:

not specified

Principles of method if other than guideline:

The skin irritation and/or sensitisation potential of the test substance was evaluated following repeated application under occlusive patch test conditions to the skin of human subjects.

GLP compliance:

no

Species:

other: human, healthy volunteers

Type of coverage:

occlusive

Preparation of test site:

not specified

Vehicle:

water

Amount / concentration applied:

7.5% preparation of the test substance

Duration of treatment / exposure:

- Preliminary experiment: 24 h

Number of animals:

50

Details on study design:

The skin reactions (erythema, edema as well as other irritation signs) were then scored.

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

The absence of any visible irritation following an application indicated that the test substance was not acting as a primary irritant.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the study conditions, the test substance was concluded to be a non irritating to skin.

Executive summary:

A study was conducted to determine the skin irritation potential of the test substance (purity not specified), according to the human repeated insult patch test (HRIPT). In the induction phase, a 7.5% test substance preparation (in distilled water) was applied epicutaneously to 50 healthy volunteers for 24 h under an occlusive type of coverage. The applications were done daily on Monday, Tuesday, Wednesday and Thursday for 3 consecutive weeks. After a rest period of ca. 2 weeks, the test substance was applied under the same conditions to a new site as a challenge. After 24 h, the occluded patch was removed and the site was read for immediate response. Follow-up readings were made 24, 48 and 72 h later. The skin effects were then scored for irritation (erythema, edema as well as other irritation signs). During Week 1 of the induction period, no visible irritation was observed in any of the 50 individuals, indicating that the test substance was not acting as a primary irritant. During the second week, visible irritation (slight erythema) was observed in one individual. During Week 3, irritation was recorded in 2 individuals (slight to marked erythema). This was considered as a manifestation of skin fatigue resulting from the cumulative effect of 11 or more applications. No visible irritation or skin sensitisation response was observed in any of the 50 individuals following challenge. The absence of any visible irritation resulting from the challenge application confirmed that the test substance was not acting as a primary skin irritant. Therefore, under the study conditions, the test substance was concluded to be no irritating to skin (Product Investigation Inc., 1977).

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From May 16, 2017 to June 16, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Deviations:

yes

Remarks:

Optical Density (OD) values were obtained with blanks higher than 0.1 (0.191), causing a deviation from the acceptance criteria. However, this is not considered to be an issue in the interpretation of this study data.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Supplier batch/lot No.: 0000974911; Purity: 100 %; Physical state: light amber liquid

Test system:

human skin model

Source species:

other:

Cell type:

non-transformed keratinocytes

Cell source:

other: reconstructed human epidermal model EpiDermTM

Justification for test system used:

Initially the predictive capacity of the modified EpiDerm™ Skin Irritation Test (SIT) test method, using MatTek EpiDermTM tissue model EPI-200, underwent full prospective validation from 2003-2007. The test method components of this method were used to define the essential test methods components of the original and updated ECVAM Performance Standards (PS).
A modification of the original EpiDerm™ SIT was validated using the original ECVAM PS in 2008. In 2008, ESAC concluded that the Modified EpiDerm™ SIT has sufficient accuracy and reliability for prediction of R38 skin irritating and no-label (non-skin irritating) test substances.

Vehicle:

other:

Details on test system:

The reconstructed human epidermal model EpiDermTM (EPI-200-MatTek Corporation) consists of normal human-derived epidermal keratinocytes which have been cultured to form a multi-layered highly differentiated model of the human epidermis. It consists of organised basal, spinous and granular layers and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo.

Lot No.: 25819
Keratinocyte Strain: 00267

MatTek’s EpiDermTM model has been extensively characterised for multiple parameters including morphology, tissue viability, skin barrier function and sterility. QC results for the specific lot of models received (Lot# 25819) were checked in-house for MatTek acceptance ranges with the following outcome:
- Morphology - PASS
- Tissue viability - PASS
- Skin barrier function (ET50 value for 1% Triton X-100) where ET50 is the time taken for 1% Triton X-100 to reduce the viability of the skin model to 50% relative to the negative control)- PASS
- Sterility testing showed no contamination during long term antibiotic and antimycotic free culture- PASS

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Single topical application of 30 μl of neat test substance.

Duration of treatment / exposure:

60 minutes (25 minutes at room temperature and 35 minutes at 37°C, 5% CO2, 95% RH).

Duration of post-treatment incubation (if applicable):

42 hours

Number of replicates:

Three tissues per condition (n=3).

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Mean

Value:

ca. 102.6

Vehicle controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

All validity criteria for the test were met:
- Criteria: the mean OD570 of the negative control (treated with DPBS) tissues is ≥ 0.8 and ≤ 2.8
Result for the test: 1.777

- The mean of the positive control relative percentage viability must be ≤ 20 % of the mean of the negative controls.
Result for the test: 3.8 %

- The standard deviation of OD values for triplicate skin models in each experimental condition must be < 18 %
Results for the test:
NC: 5 %
PC: 0.72 %
Test substance: 11.97%

Optical Density (OD) values obtained with blanks were higher than 0.1 (0.191) causing a deviation from acceptance criteria 4. However, the spectrophotometer was fully validated and had passed all required tests. The OD values for blanks observed in this study are consistent with historical data using this spectrophotometer in the XCellR8 laboratory and meet our current internal acceptance criteria of blank OD values <0.194 (mean of XCellR8 historical data, based on blanks obtained during the last 66 studies), therefore this is not considered to be an issue in the interpretation of this study data.
This SOP and guideline deviation was not considered to have affected the integrity or interpretation of the results as no equivocal results were obtained.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the study conditions, the test substance was considered to be non-irritating to skin.

Executive summary:

An in vitro study was conducted to determine the skin sensitising potential of the test substance using the Direct Peptide Reactivity Assay (DPRA) according to OECD Guideline 442C, in compliance with GLP. The substance was incubated for 24 h (± 2 h) at 25 ± 2.5˚C in a solution at 100 mM in combination with either cysteine or lysine-containing peptides, then run on a High Performance Liquid Chromatography (HPLC) system with UV detection to measure peptide concentrations. The test substance was compared to vehicle controls containing solvent in combination with either cysteine or lysine in order to determine the relative percent peptide depletion. Cinnamic aldehyde was used as positive control substance. Relative percent peptide depletion values were used in a prediction model that assigns the test substances to one of four reactivity classes. The substance produced 1.599% mean cysteine and lysine peptide depletion Using the cysteine 1:10 / lysine 1:50 prediction model, the test substance was therefore classified as a non-sensitiser, with no or minimal reactivity. A single HPLC analysis for both the cysteine and the lysine peptides was considered sufficient as the result was unequivocal. Acceptance criteria for all controls and the test substance were met in both runs with the exception of Ref A for cysteine which was marginally outside the range (0.556 mM, range 0.45 mM to 0.55 mM). This was considered acceptable as it was only slightly outside the range and did not affect any of the other samples or controls in the run. Under study conditions, the test substance was concluded to be non-sensitising to skin (XCellR8, 2018).

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:

1972

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Section 191.12 of the Federal Hazardous Substances Labelling Act Regulations

Principles of method if other than guideline:

0.1 mL of test substance was instilled in the right eyes of 6 rabbits, the untreated left eye served as controls.

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

0.1 mL of a 75% test substance solution

Observation period (in vivo):

The animals were examined after 1, 2, 3, 4 and 7 d following application.

Number of animals or in vitro replicates:

6

Details on study design:

The effects of the cornea, the iris and the conjunctivae were evaluated.

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

2

Remarks on result:

no indication of irritation

Remarks:

Result also represents 4 and 7 d time points

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

Result also represents 4 and 7 d time points

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

3

Remarks on result:

no indication of irritation

Remarks:

Result also represents 4 and 7 d time points

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

Result also represents 4 and 7 d time points

Interpretation of results:

GHS criteria not met

Conclusions:

Under the study conditions, the test substance was considered to be not irritating to eyes.

Executive summary:

A study was conducted to determine the eye irritation potential of the test substance (purity: 75%) in rabbits, according to Federal Hazardous Substances Labelling Act. In this study, 0.1 mL of test substance at a concentration of 75% in water was instilled in the right eyes of 6 rabbits and the untreated left eye served as controls. The animals were examined 1, 2, 3, 4 and 7 d following application. The effects on the cornea, the iris and the conjunctivae were evaluated. The test substance did not cause irritation to the eyes of rabbits following exposure. Under the study conditions, the test substance was therefore considered to be not irritating to eyes (South Mountain Laboratories, 1972).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin

Study 1:

An in vitro study was conducted to determine the skin irritation potential of the test substance (purity: assumed to be >96%) using the Reconstructed Human Epidermis Test Method according to OECD Guideline 439, in compliance with GLP. Three tissues of the human skin model EpiDermTM were treated with 30 µL of the test substance, the positive or the negative control for 60 minutes (25 minutes at room temperature and 35 minutes at 37°C, 5% CO2, 9 % RH), with a 42 h post-incubation period. DPBS was used as negative control and 5% of sodium dodecyl sulphate solution in water was the positive control. Subsequently, the viability of the tissues was assessed and compared to the negative control. The percentage viability was determined to be 102.6%, therefore the test substance was classified as non-irritating to skin under the conditions of the study (XCellR8, 2017).

 

Study 2:

A study was conducted to determine the skin irritation potential of the test substance (purity not specified), according to the human repeated insult patch test (HRIPT). In the induction phase, a 7.5% test substance preparation (in distilled water) was applied epicutaneously to 50 healthy volunteers for 24 h under an occlusive type of coverage. The applications were done daily on Monday, Tuesday, Wednesday and Thursday for 3 consecutive weeks. After a rest period of ca. 2 weeks, the test substance was applied under the same conditions to a new site as a challenge. After 24 h, the occluded patch was removed and the site was read for immediate response. Follow-up readings were made 24, 48 and 72 h later. The skin effects were then scored for irritation (erythema, edema as well as other irritation signs). During Week 1 of the induction period, no visible irritation was observed in any of the 50 individuals, indicating that the test substance was not acting as a primary irritant. During the second week, visible irritation (slight erythema) was observed in one individual. During Week 3, irritation was recorded in 2 individuals (slight to marked erythema). This was considered as a manifestation of skin fatigue resulting from the cumulative effect of 11 or more applications. No visible irritation or skin sensitisation response was observed in any of the 50 individuals following challenge. The absence of any visible irritation resulting from the challenge application confirmed that the test substance was not acting as a primary skin irritant. Therefore, under the study conditions, the test substance was concluded to be no irritating to skin (Product Investigation Inc., 1977).

 

Eyes

A study was conducted to determine the eye irritation potential of the test substance (purity: 75%) in rabbits, according to Federal Hazardous Substances Labelling Act. In this study, 0.1 mL of test substance at a concentration of 75% in water was instilled in the right eyes of 6 rabbits and the untreated left eye served as controls. The animals were examined 1, 2, 3, 4 and 7 d following application. The effects on the cornea, the iris and the conjunctivae were evaluated. The test substance did not cause irritation to the eyes of rabbits following exposure. Under the study conditions, the test substance was therefore considered to be not irritating to eyes (South Mountain Laboratories, 1972).

Justification for classification or non-classification

Based on the results of in vitro and in vivo irritation studies, the test substance does not warrant classification for skin and eye irritation according to EU CLP criteria (Regulation 1272/2008/EC).