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EC number: 230-989-6 | CAS number: 7394-38-9
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Skin sensitisation
Administrative data
- Endpoint:
- skin sensitisation: in chemico
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 20 October 2017 - 24 January, 2018
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 018
- Report date:
- 2018
Materials and methods
Test guidelineopen allclose all
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))
- Version / remarks:
- 4 February 2015
- Deviations:
- no
- Qualifier:
- according to guideline
- Guideline:
- other: DB-ALM (INVITTOX) Protocol 154: Direct Peptide Reactivity assay (DPRA) for skin sensitisation testing
- Deviations:
- no
- Qualifier:
- according to guideline
- Guideline:
- other: SANCO Guideline 3030/99 rev.4, Technical Material and Preparations: Guidance for generating and reporting methods of analysis in support of pre- and post-registration data requirements for Annex II and Annex III of Directive 91/414
- Version / remarks:
- July 11, 2000
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Type of study:
- other: Direct Peptide Reactivity Assay – DPRA
Test material
- Reference substance name:
- p-nitrobenzoic acid, compound with 2,2',2''-nitrilotriethanol (1:1)
- EC Number:
- 230-989-6
- EC Name:
- p-nitrobenzoic acid, compound with 2,2',2''-nitrilotriethanol (1:1)
- Cas Number:
- 7394-38-9
- Molecular formula:
- C7 H5 N O4 . C6 H15 N O3
- IUPAC Name:
- p-nitrobenzoic acid, compound with 2,2',2''-nitrilotriethanol (1:1)
- Test material form:
- solid: particulate/powder
- Details on test material:
- Lot no. 2601LP2609
Storage: At room temperature, protected from light
Constituent 1
In chemico test system
- Details on the study design:
- Principle of the DPRA Method
The reactivity of a test chemical and synthetic cysteine or lysine containing peptides was evaluated by combining the test chemical with a solution of the peptide (reaction samples) and monitoring the remaining concentration of the peptide following 24 ± 2 hours of interaction time at room temperature (25 ± 2.5°C). The peptide is a custom material containing phenylalanine to aid in detection and either cysteine or lysine as the reactive centre. Relative concentrations of the peptide following the 24 hour reaction time were determined by HPLC with gradient elution and UV detection at 220 nm. Samples were prepared and analysed in triplicates in batches to keep the total HPLC analysis time less than 30 hours.
Steps of the DPRA Method done in chronological order
- Solubility assessment of the test chemical – ultrapure water was used as a solvent
- Preparation of buffer solutions
- Pre-weighting of test chemicals and positive control
- Pre-weighting of cysteine or lysine peptide for the stock solution
- Test chemical and positive control solution preparation
- Peptide stock solution preparation
- Serial dilution of standards
- Assembling of standards, reaction samples, positive controls, reference controls (A, B and C) and co-elution controls. For each set of control/sample replicates, the triplicate vials are prepared individually but from the same solutions.
- Preparation of HPLC system (column equilibration)
- HPLC analysis
- Data evaluation
The vials were capped, vortexed to mix and placed to the HPLC autosampler for 24 ± 2 h incubation at 25± 2.5 ° C in the dark. HPLC analysis of the batch of reaction samples started 24 ± 2 h hours after the test chemical was added to the peptide solution. The batches were consisted of 2 parts: one part with the A reference controls, the calibration standards and the co-elution controls. These samples could be run before the 24 ± 2 h incubation time ends and right before the other part started or right after the other part. The other part contained the B and C reference controls, the positive controls and the reaction samples and these samples were run right after the 24 ± 2 h incubation time ended.
Demonstration of Proficiency
Prior to routine use of the method, TOXI-COOP ZRT. demonstrated technical proficiency in a separate study (Study number.: 392-442-2996) by correctly obtaining the expected DPRA prediction for 10 proficiency substances as recommended in the OECD TG 442C guideline.
Rejected Runs and Failure to Meet Acceptance Criteria
Individual chromatograms or runs could be rejected if the failure could be attributed to an assignable cause (e.g. error in reagent preparation, pipetting error, instrument failure). Reasons for rejections are indicated and discussed in the raw data. Rejected runs were repeated accordingly. Rejected chromatograms are also printed and reported in the raw data.
Percent peptide depletion
The concentration of the peptide was determined in each reaction sample from absorbance at 220 nm, measuring the peak area of the appropriate peaks and calculating the concentration of the peptide using the linear calibration curves derived from the standards.
The percent peptide depletion was determined in each reaction sample measuring the quotient of the peak area and the mean reference control C peak area, according to the formula described below.
peptide percent depletion =[1-( (peak area of the reaction sample)/(mean peak area of reference controls C ) )]× 100
Co-elution
The test chemical did not absorbed at 220 nm significantly at the same retention time as the peptides. Thus, there was no co-elution of the test chemical observed with either of the peptides (see representative chromatograms in Appendix I). The range of retention times for cysteine peptide was between 8.396 and 8.488. The range of retention times for lysine peptide was between 6.064 and 6.183.
Apparatus
HPLC System Conditions
HPLC system: SHIMADZU LC2030 (Prominence-i LC-2030C)
Serial number: L21445402951AE
Column: Zorbax SB-C18 (2.1 x 100 mm, 3.5 µm)
Serial number: USRY003976
Column temperature: 30°C
Sample temperature: 25°C
Detector: 220 nm (258 nm)
Injection volume: 7µL
System equilibration: 50% phase A and 50% phase B for 2 hours at 30°C and running the gradient twice before injecting the first sample
Run time: 20 min
Flow conditions: gradient flow
Table 2. Gradient flow conditions
Time Flow A phase (%) B phase (%)
0 min 0.35 mL / min 90 10
10 min 75 25
11 min 10 90
13 min 10 90
13.5 min 90 10
20 min gradient ends
Buffer Solutions
Phosphate buffer pH 7.5 ± 0.05
18 (v/v) % 0.1 M sodium phosphate monobasic
(of Sodium Phosphate Monobasic Monohydrate (NaH2PO4 · H2O) in purified water)
82 (v/v) % 0.1 M sodium phosphate dibasic
(of Sodium Phosphate Dibasic Heptahydrate (Na2HPO4 · 7H2O) in purified water)
pH was adjusted with either the monobasic or dibasic solution
Ammonium acetate buffer pH 10.2 ± 0.05
- 0.1 M Ammonium Acetate (CH3CO2NH4) in purified water
- pH was adjusted with Ammonium Hydroxide (NH4OH) drop by drop
Peptide Stock Solutions
Cysteine peptide, 0.667 mM, 0.501 mg/mL stock solution:
The needed amount of peptide was calculated based on the equation below (0.01312 g ± 10%). The previously calculated amount of the peptide (0.01352 g) was pre-weighted and 25 mL of pH 7.5 phosphate buffer was added in the volumetric glass right before beginning the assay.
Lysine peptide, 0.667 mM, 0.518 mg/mL stock solution:
The needed amount of peptide was calculated based on the equation below (0.01385 g ± 10%). The previously calculated amount of the peptide (0.01391 g) was pre-weighted and 25 mL of pH 10.2 acetate buffer was added in a volumetric glass right before beginning of the assay.
In a 25 mL volumetric glass:
(molecular weight)/(% purity) ×250=calculated amount of the peptide (mg)
Calibration Solutions
Six calibration standard points were prepared by serial dilution of the peptide stock solutions with the following nominal molarities: STD 1 = 0.534 mM, STD 2 = 0.267 mM, STD 3 = 0.1335 mM, STD 4 = 0.0667 mM, STD 5 = 0.0334 mM and STD 6 = 0.0167 mM. As dilution buffer a 20% acetonitrile:buffer solution (phosphate or ammonium acetate) was used. For the zero standard point (STD 7 = 0 mM) dilution buffer was used.
Positive Control Stock Solutions
100 mM solutions of the positive control chemical in acetonitrile were prepared just before use. The needed amount of test chemical was calculated (0.0668 g ± 10%) based on the molecular weight and purity of the substance with the equation below. 0.0665 g Cinnamaldehyde was weighted for the positive stock solution used for the cysteine peptide depletion determination and 0.0665 g Cinnamaldehyde was weighted for the stock solution used for lysine peptide depletion determination.
In a 5 mL volumetric glass:
(molecular weight)/(% purity) ×50=calculated amount of the peptide (mg)
Test Chemical Stock Solutions
100 mM solutions of the test chemical in the appropriate solvent (Section 5.1.3) were prepared just before use. The needed amount of test chemical was calculated (0.1614 g ± 10 %) and weighted based on the single average molecular weight. 0.1647 g test chemical was weighted for the stock solution used for the cysteine peptide depletion determination and 0.1645 g test chemical was weighted for the stock solution used for lysine peptide depletion determination.
Phases for HPLC
Mobile Phase A – 0.1 % (v/v) trifluoroacetic acid in ultra-pure water
Mobile Phase B – 0.085 % (v/v) trifluoroacetic acid in acetonitrile
Mobile Phase C – 50 - 50 % (v/v) acetonitrile and ultrapure water
Results and discussion
- Positive control results:
- The acceptance criteria were met in case of the positive control with the cysteine peptide depletion value of 73.08 % and a mean lysine peptide depletion value of 52.80 %. The SD of the percent peptide depletions of the positive control was 0.76 % and 0.42 % for the cysteine and lysine depletion respectively.
In vitro / in chemico
Results
- Key result
- Parameter:
- other: Mean % obtained peptide depletion
- Value:
- 5.83
- Vehicle controls validity:
- valid
- Negative controls validity:
- valid
- Positive controls validity:
- valid
- Remarks on result:
- no indication of skin sensitisation
- Other effects / acceptance of results:
- The chromatograms were evaluated with the help of “LabSolutions” software and the calculations were carried out using “Microsoft Office Excel”.
System suitability
Reference control A replicates were included in HPLC run the sequence to verify the HPLC system suitability prior the analysis. The mean peptide concentration of A reference control sample replicates was 0.51 mM for the cysteine peptide and 0.49 mM for the lysine peptide.
A standard calibration curve was generated for both cysteine and lysine peptides using serial dilutions standards from the peptide stock solutions. Calibration standard points were analysed by linear regression. Means of the peak areas versus the concentrations of both peptides showed good linearity with r2 = 0.9993 for the cysteine peptide and r2 = 1.0000 for the lysine peptide, covering the concentration range from 0.534 mM to 0.0167 mM. The back-calculated values for all the nominal concentrations of both peptides were within the acceptance criteria, not more than 16 % for the LOQs and not more than 12 % for the other calibration standards. Thus, all standards were accepted. All system suitability criteria were within acceptable limits and therefore the runs can be considered valid.
Analysis sequences
Reference control B replicates were included in the sequence to verify the stability of the peptide over time and reference control C replicates were used to verify that the solvent of the test item did not impact the percent peptide depletion. The mean cysteine peptide concentration of the reference control C replicates was 0.49 mM and the mean lysine peptide concentration of the reference control C replicates were 0.49 mM, which were within the acceptable 0.50 ± 0.05 mM range. Moreover the CV % for the nine reference control B and C replicates in acetonitrile and water respectively were much smaller than the acceptable 15 % for both peptides, since it was 0 % and 1 % for cysteine and lysine peptides. All validity criteria were within acceptable limits and therefore the study can be considered valid.
Cysteine and lysine depletion and mean peptide depletion of the test item
The acceptance criteria were met in case of the positive control with the cysteine peptide depletion value of 73.08 % and a mean lysine peptide depletion value of 52.80 %. The SD of the percent peptide depletions of the positive control was 0.76 % and 0.42 % for the cysteine and lysine depletion respectively.
The percent cysteine peptide depletion with the test item was 7.85 % while the percent lysine depletion was 3.80 %. The maximum standard deviation for the test chemical replicates was 4.31 % for the percent cysteine depletion and 0.70 % for the percent lysine depletion.
In Appendix II for the test chemical, the peptide peak areas of each replicate, their mean and CV %, the peptide depletion values for each replicate, their mean and SD and description of all relevant observations (solubility, precipitate, co-elution) are shown.
Assigning the test chemical to a reactivity class and category
The mean percent cysteine and percent lysine depletion values were calculated for the test chemical and the positive control. By using the cysteine 1:10 / lysine 1:50 prediction model, the threshold of 6.38 % average peptide depletion was used to support the discrimination between skin sensitisers and non-sensitisers in the framework of Integrated Approaches to Testing and Assesment (IATA). Application of the prediction models assigned the test chemical to a reactivity class (minimal, low, moderate or high reactivity).
On the basis of the cysteine 1:10 / lysine 1:50 prediction model, chemicals assigned to the minimal reactivity class should be classified as non-sensitisers whereas chemicals assigned to the low, moderate or high reactivity class should be classified as sensitisers.
The percent cysteine peptide depletion was 7.85 % while the percent lysine depletion was 3.80 %. The mean of percent cysteine and lysine peptide depletion of p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1) was 5.83 % which is a minimal reactivity class classifying the test chemical into the non-sensitizer reactivity category.
Any other information on results incl. tables
Reference control A replicates for cysteine peptide
|
Peptide peak area at 220 nm |
Peptide conc. calculated (mM) |
Peptide peak area |
Peptide concentration |
|||
Mean |
CV % |
Mean (mM) |
SD |
CV % |
|||
ref A I |
2312357 |
0.51 |
2298160 |
1% |
0.51 |
0.0054 |
1% |
ref A II |
2270274 |
0.50 |
|||||
ref A III |
2311848 |
0.51 |
Reference control A replicates for lysine peptide
|
Peptide peak area at 220 nm |
Peptide conc. calculated (mM) |
Peptide peak area |
Peptide concentration |
|||
Mean |
CV % |
Mean (mM) |
SD |
CV % |
|||
ref A I /1 |
2325482 |
0.49 |
2342526 |
1% |
0.49 |
0.0052 |
1% |
ref A I / 2 |
2323877 |
0.49 |
|||||
ref A I / 3 |
2325266 |
0.49 |
|||||
ref A II |
2361455 |
0.50 |
|||||
ref A III |
2376552 |
0.50 |
Reference control B and C replicates for cysteine peptide
Name, replicate number |
Peptide peak area at 220 nm |
Peptide conc. calculated (mM) |
Peptide peak area |
Peptide concentration |
|||
Mean |
CV % |
Mean (mM) |
SD |
CV % |
|||
ref B I |
2277206 |
0.51 |
2229905 |
3% |
0.50 |
0.0132 |
0% |
ref B II |
2314043 |
0.51 |
|||||
ref B III |
2273305 |
0.50 |
|||||
ref B I / 2 |
2183832 |
0.49 |
|||||
ref B II / 2 |
2241259 |
0.50 |
|||||
ref B III / 2 |
2186396 |
0.49 |
|||||
ref C I |
2269044 |
0.50 |
|||||
ref C II |
2196368 |
0.49 |
|||||
ref C III |
2127689 |
0.47 |
Reference control B and C replicates for lysine peptide
Name, replicate number |
Peptide peak area at 220 nm |
Peptide conc. calculated (mM) |
Peptide peak area |
Peptide concentration |
|||
Mean |
CV % |
Mean (mM) |
SD |
CV % |
|||
ref B I |
2358218 |
0.49 |
2350478 |
0% |
0.49 |
0.0051 |
1% |
ref B II |
2367146 |
0.50 |
|||||
ref B III |
2372111 |
0.50 |
|||||
ref B I / 2 |
2361731 |
0.50 |
|||||
ref B II / 2 |
2364654 |
0.50 |
|||||
ref B III / 2 |
2372738 |
0.50 |
|||||
ref C I |
2331096 |
0.49 |
|||||
ref C II |
2310946 |
0.48 |
|||||
ref C III |
2315666 |
0.49 |
Cysteine peptide depletion values for the positive control and the test item
Name, replicate number |
Peptide peak area at 220 nm |
Peptide conc. calculated (mM) |
Peptide depletion |
|
% |
SD (%) |
|||
ref C, rep I |
2269044 |
0.50 |
- |
- |
ref C, rep II |
2196368 |
0.49 |
- |
|
ref C, rep III |
2127689 |
0.47 |
- |
|
p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1), rep I |
2026171 |
0.45 |
10.70 % |
4.31 |
p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1), rep II |
1977588 |
0.44 |
9.96 % |
|
p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1), rep III |
2066181 |
0.46 |
2.89 % |
|
CINNAMALDEHYDE, rep I |
604294 |
0.13 |
73.27 % |
0.76 |
CINNAMALDEHYDE, rep II |
609531 |
0.14 |
72.24 % |
|
CINNAMALDEHYDE, rep III |
586063 |
0.13 |
73.72 % |
Lysine peptide depletion values for the positive control and the test item
Name, replicate number |
Peptide peak area at 220 nm |
Peptide conc. calculated (mM) |
Peptide depletion |
|
% |
SD (%) |
|||
ref C, rep I |
2331096 |
0.49 |
- |
- |
ref C, rep II |
2310946 |
0.48 |
- |
|
ref C, rep III |
2315666 |
0.49 |
- |
|
p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1), rep I |
2224712 |
0.47 |
4.56% |
0.70 |
p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1), rep II |
2226839 |
0.47 |
3.64% |
|
p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1), rep III |
2241845 |
0.47 |
3.19% |
|
CINNAMALDEHYDE, rep I |
1124094 |
0.24 |
52.33% |
0.42 |
CINNAMALDEHYDE, rep II |
1109162 |
0.23 |
53.14% |
|
CINNAMALDEHYDE, rep III |
1116488 |
0.23 |
52.93% |
Mean peptide depletion values for the positive control and the test chemical
Name, replicate number |
Obtained mean % cysteine peptide depletion |
Obtained mean % lysine peptide depletion |
Mean % obtained peptide depletion |
p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1) |
7.85 % |
3.80 % |
5.83 % |
CINNAMALDEHYDE |
73.08 % |
52.80 % |
62.94 % |
Prediction model Cysteine 1:10 / Lysine 1:50
Mean depletion values |
Reactivity class |
Reactivity category |
Less than 6.38 % |
Minimal reactivity |
NON-SENSITISER |
Between 6.38 % and 22.62 % |
Low reactivity |
SENSITISER |
Between 22.62 % and 42.47 % |
Moderate reactivity |
|
More than 42.14 % |
High reactivity |
Applicant's summary and conclusion
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- The test item was formulated with ultrapure water to obtain a homogenous solution at a concentration of 100 mM. The back calculated values of the reference control replicates were within the expected molarity concentration range and the linearity of standard calibration points showed good linearity.
The positive control replicates showed the expected percent peptide depletion values within acceptable limits. The experiment was considered to be valid.
Results obtained from this in chemico Direct Peptide Reactivity Assay, with the test item p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1) indicated that the test item is not a potential skin sensitiser. The mean percent peptide depletion value of p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1) was 5.83 %, which assigned the test chemical to the minimal reactivity class and a non-sensitiser category.
The DPRA result has been considered scientifically valid for the evaluation of the skin sensitisation potential. Consequently, information generated by the DPRA can already be used in a weight-of-evidence approach to support regulatory decision making, e.g to characterise equivocal responses in in vivo studies (e.g. conflicting results from multiple studies). Moreover, for the purposes of some regulations (for example REACH in the EU) a positive DPRA result should be considered sufficient to classify a test material as a skin sensitizer. However correct prediction of skin sensitisation potential of substances requires integration of information from multiple sources. Additionally combination of non-animal methods (in silico, in chemico, in vitro) within IATA will be needed to fully substitute for the animal tests currently in use, given the restricted AOP mechanistic coverage of each of the currently available non-animal test methods. - Executive summary:
This study was undertaken to evaluatethe skin sensitization potential of the test itemp-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1)in chemico. The Direct Peptide Reactivity Assay (DPRA) proposed the molecular initiating event of the skin sensitisation Adverse Outcome Pathway (AOP), namely protein reactivity, by quantifying the reactivity of the test chemical towards cysteine and lysine model synthetic peptides.
Before beginning the assay thesolubility of the test chemical was assessed and ultrapure water was chosen as the appropriate solvent. Test chemical stock solutions were prepared in ultrapure water at the concentration of 100 mM. Cysteine and lysine peptide stock solutions were prepared at the concentrations of 0.501 mg/mL and 0.518 mg/mL with sodium phosphate buffer (pH=7.5) and ammonium acetate buffer (pH=10.2) respectively. Calibration standards were made by serial dilutions from the peptide stock solutions. Positive control stock solutions were prepared in acetonitrile at the concentration of 100 mM.The test chemical stock solutions were combined with the peptide stock solutions (1:10 and 1:50 ratio with cysteine and lysine peptides respectively) asreaction samples. Positive controls, reference controls and co-elution controls were assembled with the peptide stocks.The vials were placed to the HPLC autosampler for 24 ± 2 h incubation at 25 ± 2.5 °C in the dark.High performance liquid chromatography (HPLC) analysis of the batch of reaction samples started after the incubation peiod. Concentrations of the peptides following reaction time were determined by HPLC with gradient elution and UV detection at 220 nm.
Cysteine and lysine depletion values were used to categorize the test chemical in one of four classes of reactivity. By using the cysteine 1:10 / lysine 1:50 prediction model, the threshold of 6.38 % mean percent peptide depletion was used to support the discrimination between skin sensitisers and non-sensitisers in the framework of Integrated Approaches to Testing and Assesment (IATA).
The positive control replicates showed the expected percent peptide depletion values within acceptable limits. The back-calculated values of the reference control replicates were within the expected molarity concentration range. The experiment was considered to be valid.
The mean percent peptide depletion value ofp-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1)was 5.83 %, which is under the 6.38 % threshold of discrimination between sensitisers and non sensitisers.Results obtained from this
in chemicoDirect Peptide Reactivity Assay, with the test item p-Nitrobenzoic acid, compound with 2,2’,2”-nitrilotriethanol (1:1) indicated that the test item is not a potential skin sensitiser.
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