1,2-Cyclohexanedicarboxylic Acid, 1-(phenylmethyl) ester, ester with 2,2,4-trimethyl, 1,3-petanediol mono(2-methyl propanoate)

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020-01-02 to 2020-01-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

22nd July 2010

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

2003

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

1,2-Cyclohexanedicarboxylic Acid, 1-(phenylmethyl) ester, ester with 2,2,4-trimethyl, 1,3-petanediol mono(2-methyl propanoate)

EC Number:

950-347-5

Cas Number:

1661012-65-2

Molecular formula:

C27H40O6

IUPAC Name:

1,2-Cyclohexanedicarboxylic Acid, 1-(phenylmethyl) ester, ester with 2,2,4-trimethyl, 1,3-petanediol mono(2-methyl propanoate)

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: Sponsor (Valtris Speciality Chemicals, Lot #: 5084; PSL REFERENCE NO.:191121-1H)
- Expiration date of the lot/batch: 2020-09-05
- Purity test date: Not specified

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: stored at room temperature
- Stability under storage conditions: Test substance was stable for the duration of testing
- Stability under test conditions: Test substance was stable for the duration of testing
- Solubility and stability of the test substance in the solvent/dispersant/vehicle/test medium: Solubility testing conducted by the laboratory indicated that the test substance was soluble in acetone/olive oil (4:1 v/v) AOO.

FORM AS APPLIED IN THE TEST (if different from that of starting material) : Clear liquid

In vivo test system

Test animals

Species:

mouse

Strain:

CBA:J

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Animals received from Envigo RMS Inc. on December 11, 2019 (Preliminary Irritation Group Animals) and on December 18, 2019 (Test and Control Group Animals)
- Females (if applicable) nulliparous and non-pregnant: Yes. Females ,nulliparous and non-pregnant
- Microbiological status of animals, when known: Not specified
- Age at study initiation: Preliminary Animals: Young adult (12 weeks); Test and Control Animals: Young adult (11 weeks) at experimental start.
- Weight at study initiation: Test and Control Animals: 19.1 - 25.3 grams at experiment start
- Housing: individually housed in plastic solid bottom cages during the dosing and resting phase of the study. After final weighing until sacrifice, animals were housed in their respective dose groups in plastic cages with bedding. Bedding in the plastic, solid bottom cages was changed at least once per week. Enrichment (e.g., nesting material) was placed in each cage. All caging conformed to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011).
- Diet (e.g. ad libitum): Envigo Teklad Global 16% Protein Rodent Diet® #2016 ad libitum
- Water (e.g. ad libitum): Filtered tap water supplied ad libitum.
- Acclimation period: 21 or 22 days
- Indication of any skin lesions: Not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-23ºC
- Humidity (%): 38-51%
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

- IN-LIFE DATES: From: 2019-12-11 To: 2020-01-14

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

Concentrations of 10%, 25%, 50% and 100% were selected for the main test based on results of the preliminary screening test. Dilutions of the test substance were prepared as w/w mixtures in AOO. The vehicle control, AOO, and a single concentration of a 25% w/w mixture of the positive control HCA in AOO were also prepared. All dosage preparations were freshly prepared on the day of application.

No. of animals per dose:

Preliminary Irritation: 2/group
Test (4 groups): 5/group
Vehicle (Negative) Control: 5/group
Positive Control: 5/group

Details on study design:

PRE-SCREEN TESTS:
- Compound solubility: The test substance, as received (neat), was mixed well prior to use. Solubility testing conducted by the laboratory indicated that the test substance was soluble in acetone/olive oil (4:1 v/v) AOO. All preparations were mixed well prior to dosing.
- Irritation: The test substance concentration of 100% was tested to determine the highest achievable level. This concentration did not produce excessive local irritation.
- Systemic toxicity: The test substance concentration of 100% was tested to determine the highest achievable level. This concentration did not produce overt systemic toxicity.
- Ear thickness measurements & erythema scores: The ears of each mouse were evaluated for erythema and edema pre-dose on Day 1 and on Days 2, 3, and 6 according to the modified Draize scoring system (Draize, Woodard, & Calvary,1944).

25 µL of the test substance or the vehicle alone was applied to the dorsum of both ears of each mouse for three consecutive days. Application was done using an appropriate size I micropipette to accurately deliver25 µL. The dose was gently spread as evenly as possible over the dorsal surface of the ear using the tip of the pipette. No treatment was made on Days 4 and 5. On Day 6, the sites for each mouse were evaluated for local reactions (erythema & edema). Animals were observed daily for signs of toxicity. The Study Director used this data in conjunction with any pre-existing data to select the four concentrations to be tested. The test substance at 10%, 25%, and 50% w/w mixtures in AOO and the neat test substance were selected for the main test.

MAIN STUDY
Selection of Animals / Dose Levels
Prior to dosing, the animals were weighed and the ears were checked for any abnormalities or clinical signs of diseases or injury. Thirty healthy naïve female mice without pre-existing ear irritation were selected and distributed (5 mice per group) into the following groups:

Group Purpose Concentration
1 Vehicle Control 0%
2 Positive Control Substance 25% HCA
3 Test Substance 10%
4 Test Substance 25%
5 Test Substance 50%
6 Test Substance 100%

Concentrations were selected based on toxicity, solubility, irritancy, and viscosity

Sample Preparation
Concentrations of 10%, 25%, 50% and 100% were selected for the main test based on results of the preliminary screening test. Dilutions of the test substance were prepared as w/w mixtures in AOO. The vehicle control, AOO, and a single concentration of a 25% w/w mixture of HCA in AOO were also prepared. All dosage preparations were freshly prepared on the day of application.

Test Substance Application
Beginning on Day 1, a quantity of 25 µL of the appropriate test substance concentration, the positive control substance, or the vehicle alone was applied to the dorsum of both ears of each mouse once per day for three consecutive days (Days 1, 2,and3) using a micropipette. During application, the material was gently spread as evenly as possible over the dorsal surface of the ear using the tip of the pipette.

Dermal Scoring
Prior to each application (Days 1, 2,and 3) and on Day 6, the ears were evaluated for erythema and edema according to the modified Draize scoring system (Draize, Woodard, & Calvary,1944).

3H-methyl Thymidine Injections
On Day6 of the study (three days after the final topical application) 250 µL of sterile phosphate buffered saline (PBS) containing 20 µCi of 3H-methylthymidine was injected intravenously via the tail vein of each mouse.

Lymph Node Assessment
Approximately five hours after the injections, all test and control mice were euthanized via overdose of inhaled Isoflurane and the draining auricular lymph nodes were excised. The lymph nodes were evaluated for each individual mouse. A single cell suspension of lymph node cells (LNC) was prepared in PBS by gently massaging the lymph nodes between the frosted ends of two microscope slides over a collection vessel. The slides were then rinsed briefly with PBS into the vessel.

The contents of the vessel were transferred to a centrifuge tube and washed with an excess of PBS and centrifuged for approximately 10 minutes at 1800 rpm, with an relative centrifugal force (RCF) of 489G. This process was carried out twice. In both cases, the supernatant was decanted and discarded following each centrifugation. After the second wash, 5 mL of the 5% trichloroacetic acid (TCA) in distilled water was then added to the sediment and the tube was vortexed briefly. The DNA was then precipitated in the 5% TCA in distilled water at approximately 4°C overnight (approximately 18 hours).

Following the overnight precipitation of the DNA, the tubes were centrifuged again for approximately 10 minutes at 1800 rpm and the supernatant was discarded. The resulting precipitate was re-suspended using 1 mL of the 5% TCA in distilled water and transferred to 10 mL of scintillation fluid. Incorporation of 3H-methyl thymidine was measured by β-scintillation counting and expressed as disintegrations per minute, minus background dpm.

In-life Observations
All test, control and preliminary mice were observed for signs of mortality, gross toxicity, and/or behavioral changes daily. Preliminary mice were euthanized via CO2 inhalation and all test and control mice were euthanized via overdose of inhaled Isoflurane anaesthetic on Day 6.

Body Weights
Individual body weights of test and control animals were recorded on Day 1 (initial) shortly before test substance application and prior to IV injections on test Day 6.

EVALUATION
The mean and standard deviation of the dpm values were calculated for each dose group. A stimulation index (SI) was derived for each experimental group by dividing the mean dpm of each experimental group by the mean dpm of the vehicle control group. Any test substance that produces an SI 3 in the LLNA is normally considered “positive” for dermal sensitization potential (Kimberetal., 1994).

The EC3 value was not calculated since all dose levels induced a stimulation index of less than 3.0.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

Statistical analysis was performed on the DPM minus background values. Significance was judged at p < 0.05. The treated groups and negative vehicle control group were compared using a One-Way Analysis of Variance (ANOVA), followed by comparison of the treated groups to control by Dunnett’s t-test for multiple comparisons. Where variances are considered significantly different by Bartlett’s test, groups were compared using a non-parametric method (Kruskal-Wallis non parametric analysis of variance followed by Dunn’s test) (INSTAT Biostatistics, Graph Pad Software, San Diego, CA). Outlier analysis was conducted using Grubbs (1969).

Results and discussion

Positive control results:

Group 2 (Positive Control – 25% HCA in AOO): Very slight erythema (score of 1) was evident at four positive control sites on Day 2, at all sites on Day 3 and at four sites on Day 6. Slight edema (score of 1) was present at two sites on Day 6. The positive control (HCA) at 25% produced a dermal sensitization response in mice (SI = 5.57). Therefore, the LLNA test system was valid for this study with Santicizer Platinum P-1700.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

< 3

Test group / Remarks:

100%

Remarks on result:

other: No skin sensitisation potential

Results 2

Key result

Parameter:

SI

Value:

< 3

Test group / Remarks:

50%

Remarks on result:

other: No skin sensitisation potential

Results 3

Key result

Parameter:

SI

Value:

< 3

Test group / Remarks:

25%

Remarks on result:

other: No skin sensitisation potential

Results 4

Key result

Parameter:

SI

Value:

< 3

Test group / Remarks:

10%

Remarks on result:

other: No skin sensitisation potential

Results 5

Key result

Parameter:

EC3

Remarks on result:

other: EC3 was not calculated since all dose levels induced a stimulation index of <3.0

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA
Preliminary Test: Preliminary irritation group scoring results are presented in Table 1.

Main Test:
Group 1 (Vehicle Control—AOO): No dermal irritation was observed for any of the vehicle control sites.
Group 2 (Positive Control—25% HCA in AOO): Very slight erythema (score of 1) was evident at four positive control sites on Day 2, at all sites on Day 3 and at four sites on Day 6. Slight edema (score of 1) was present at two sites on Day 6.
Group 3 (10% Test Substance in AOO): No dermal irritation was observed for any of the test sites.
Group 4 (25% Test Substance in AOO): No dermal irritation was observed for any of the test sites.
Group 5 (50% Test Substance in AOO): No dermal irritation was observed for any of the test sites.
Group 6 (100% Test Substance): No dermal irritation was observed for any of the test sites.

DETAILS ON STIMULATION INDEX CALCULATION
Main Test: Treatment of mice with 10%, 25%, 50% and 100% of Santicizer Platinum P-1700 resulted in stimulation index values of 0.64, 1.14, 1.21, and 1.09, respectively. As a stimulation index (SI) of less than 3.0 was observed in all the treatment groups, the test substance was not considered positive for a dermal sensitization potential. The positive control (HCA) at 25% produced a dermal sensitization response in mice (SI =5.57). Therefore, the LLNA test system was valid for this study with Santicizer Platinum P-1700.

EC3 CALCULATION
The EC3 value was not calculated since all dose levels induced a stimulation index of less than 3.0.

CLINICAL OBSERVATIONS:
Preliminary Test: All preliminary animals appeared active and healthy. Very slight erythema (score of 1) was evident at two test sites on Day 3. Preliminary irritation group scoring results and individual in-life observations are presented in Tables 1 and 2.

Main Test: All test and control animals appeared active and healthy throughout the study.

BODY WEIGHTS
Main test: Five mice from the test groups, two mice from the vehicle control group, and one mouse from the positive control group lost body weight during the study. All other mice gained body weight during the study. Results are presented in Table 3.

Any other information on results incl. tables

Table 1. Preliminary Test: Individual Dermal Irritation Scores
Animal Number	Sex	Day
		1		2		3		6
		Left	Right	Left	Right	Left^1	Right^1	Left	Right
Group 1P – 100%^2
3680	F	0/0	0/0	0/0	0/0	1/0	1/0	0/0	0/0
3681	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0

¹ Oily fur around the dose site

² 25 µL of the test substance was applied as received to each ear (50 µL total)

 

Table 2. Preliminary Test: In-life Observations
Animal Number	Sex	Group	Dose Conc. (%)	Observation	Day of Observation (x = observation is present)
					1	2	3	4	5	6
3680	F	1P	100	Active and Healthy	X	X	X	X	X	X
3681	F	1P	100	Active and Healthy	X	X	X	X	X	X

Table 3. Main Test: Individual Body Weights
Animal Number	Group	Sex	Day 1 (g)	Day 6 (g)
3601	1 Vehicle Control (AOO)	Female	21.9	22.0
3602		Female	22.8	22.6
3603		Female	20.5	21.0
3604		Female	22.6	22.3
3605		Female	21.6	21.8
3606	2 Positive Control (25% HCA in AOO)	Female	22.0	22.3
3607		Female	20.9	21.2
3608		Female	20.9	21.0
3609		Female	22.4	22.0
3610		Female	21.8	21.9
3611	3 10% Test Substance in AOO	Female	22.4	22.0
3612		Female	24.6	23.0
3613		Female	20.7	21.0
3614		Female	20.2	20.8
3615		Female	19.9	20.3
3616	4 25% Test Substance in AOO	Female	25.3	23.9
3617		Female	24.0	23.5
3618		Female	23.0	23.2
3619		Female	20.8	21.3
3620		Female	20.2	20.8
3621	5 50% Test Substance in AOO	Female	19.1	19.8
3622		Female	23.5	22.7
3623		Female	21.6	21.8
3624		Female	20.4	20.9
3625		Female	22.2	22.3
3626	6 100% Test Substance in AOO	Female	22.6	23.1
3627		Female	22.0	22.1
3628		Female	21.0	21.4
3629		Female	20.5	20.6
3630		Female	20.9	21.4

Table 4. Main Test: Individual Dermal Irritation Scores (Erythema/Edema)
Animal Number	Sex	Day
		1		2		3		6
		Left	Right	Left	Right	Left	Right	Left	Right
Group 1 – Vehicle Control^1
3601	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3602	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3603	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3604	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3605	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
Group 2 - Positive Control^2
3606	F	0/0	0/0	0/0	0/0	1/0	1/0	0/1	0/1
3607	F	0/0	0/0	0/0	0/0	1/0	1/0	1/0	1/0
3608	F	0/0	0/0	0/0	0/0	1/0	1/0	1/0	1/0
3609	F	0/0	0/0	1/0	1/0	1/0	1/0	0/0	0/0
3610	F	0/0	0/0	1/0	1/0	1/0	1/0	0/0	0/0
Group 3 – 10% Test Material^3
3611	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3612	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3613	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3614	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3615	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
Group 4 – 25% Test Material^3
3616	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3617	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3617	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3619	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3620	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
Group 5 – 50% Test Material^3
3621	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3622	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3623	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3624	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3625	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
Group 6 – 100% Test Material^4
3626	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3627	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3628	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3629	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0
3630	F	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0

¹ 25 µL of AOO was applied to each ear (50 µL total)

² 25 µL of a 25% w/w mixture of HCA in AOO was applied to each ear (50 µL total)

³ 25 µL of the test material was applied as a w/w mixture in AOO to each ear (50 µL total)

⁴ 25 µL of the test material was applied as received to each ear (50 µL total)

Table 5. Main Test: Individual and Mean DPM Values^1
Group	Animal Number	dpm	dpm minus background^2	Group Mean dpm minus background	Std. Dev	S.I^3	SI ≥ 3
Background: 58.93
1 Vehicle Control (AOO)	3601	2280.09	2221.16	2711.08	666.63	-	-
	3602	3829.58	3770.65
	3603	2947.72	2888.79
	3604	2624.33	2565.40
	3605	2168.31	2109.38
2 Positive Control (25% HCA in AOO)	3606	12978.92	12919.99	15111.45	9874.68	5.57	Yes
	3607	14248.77	14189.84
	3608	8715.97	8657.04
	3609	32139.30	32080.37*
	3610	7768.92	7709.99
3 10% Test Substance in AOO	3611	2114.94	2056.01	1728.88	239.67	0.64	No
	3612	1610.14	1551.21
	3613	1934.07	1875.14
	3614	1754.14	1695.21
	3615	1525.78	1466.85
4 25% Test Substance in AOO	3616	4821.19	4762.26	3081.15	1207.87	1.14	No
	3617	2031.04	1972.11
	3617	2073.97	2015.04
	3619	3897.53	3838.60
	3620	2876.69	2817.76
5 50% Test Substance in AOO	3621	2872.26	2813.33	3275.35	742.81	1.21	No
	3622	2663.18	2604.25
	3623	4410.35	4351.42
	3624	3800.79	3741.86
	3625	2924.80	2865.87
6 100% Test Substance in AOO	3626	6500.07	6441.14*	2945.76	2027.63	1.09	No
	3627	1650.66	1591.73
	3628	1535.79	1476.86
	3629	2740.35	2681.42
	3630	2596.57	2537.64

* The dpm values for Animal Nos.3609 and 3626 were determined to be outliers, but were included in the average and the standard deviation calculation for the test groups. There was no indication in the raw data that these animals were dosed incorrectly; therefore these animals were not excluded from the calculations.

¹ Disintegrations per minute

² Values analyzed for outliers, Grubbs1969.

³ Stimulation Index = Average dpm of Test Substance / Average dpm of Vehicle

Table 6. Main Test: Stimulation Index
Group	Group Mean dpm	SI	Sensitization Response
1 Vehicle Control (AOO)	2711.08	-	N/A
2 Positive Control (25% HCA in AOO)	15111.45	5.57	Positive – Valid Study
3 10% Test Substance in AOO	1728.88	0.64	Not a sensitizer
4 25% Test Substance in AOO	3081.15	1.14	Not a sensitizer
5 50% Test Substance in AOO	3275.35	1.21	Not a sensitizer
6 100% Test Substance in AOO	2945.76	1.09	Not a sensitizer

N/A = Not applicable

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Treatment of mice with 10%, 25%, 50% and 100% of Santicizer Platinum P-1700 resulted in stimulation index values of 0.64, 1.14, 1.21, and 1.09, respectively. As a stimulation index (SI) of less than 3.0 was observed in all the treatment groups, the test substance was not considered positive for a dermal sensitization potential. The positive control (HCA) at 25% produced a dermal sensitization response in mice (SI =5.57). Therefore, the LLNA test system was valid for this study with Santicizer Platinum P-1700. The EC3 value was not calculated since all dose levels induced a stimulation index of less than 3.0.

Based on the results observed, the test material Santicizer Platinum P-1700 was not considered to be a contact dermal sensitizerin the mouse local lymph node assay.

Executive summary:

The dermal sensitization potential of the test material (Santicizer Platinum P-1700) was evaluated in a key OECD Guideline 429 study using the mouse local lymph node

assay (LLNA). Three concentrations of the test substance (10%, 25% and 50% w/w) in acetone/olive oil (4:1 v/v) (AOO), the neat test substance (100%), and the vehicle alone were topically applied to twenty-five healthy test CBA/J female mice (five/group) for three consecutive days. Three days after the last application, the mice were given an IV injection containing 20 µCi of ³H-methyl thymidine. Approximately five hours later, all animals were euthanized via an overdose of inhaled Isoflurane and the draining (auricular) lymph nodes were harvested and prepared for analysis in a scintillation counter. The results are presented in disintegrations per minute per mouse (dpm/mouse). Each animal’s ears were also evaluated for erythema and edema prior to each application and again on Day 6, prior to the IV injection. A positive control group (five animals) was maintained under the same environmental conditions and treated with a 25% w/w mixture of HCA in AOO in the same manner as the test animals.

All preliminary test animals appeared active and healthy. Very slight erythema (score of 1) was evident at two test sites on Day 3. All test and control animals in the main test appeared active and healthy throughout the study. In the main test, five mice from the test groups, two mice from the vehicle control group, and one mouse from the positive control group lost body weight during the study. All other mice gained body weight during the study.

No dermal irritation was observed for any of the vehicle control sites Group 1 (Vehicle Control-AOO). No dermal irritation was observed for any of the test sites in animals in the test material treated groups (10%, 25%, 50%, and 100% w/w). In Group 2 (Positive Control—25% HCA in AOO), very slight erythema (score of 1) was evident at four positive control sites on Day 2, at all sites on Day 3 and at four sites on Day 6. Slight edema (score of 1) was present at two sites on Day 6.

Treatment of mice with 10%, 25%, 50% and 100% of Santicizer Platinum P-1700 resulted in stimulation index values of 0.64, 1.14, 1.21, and 1.09, respectively. As a stimulation index (SI) of less than 3.0 was observed in all the treatment groups, the test substance was not considered positive for a dermal sensitization potential. The positive control (HCA) at 25% produced a dermal sensitization response in mice (SI =5.57). Therefore, the LLNA test system was valid for this study with Santicizer Platinum P-1700. The EC₃ value was not calculated since all dose levels induced a stimulation index of less than 3.0.

Based on the results observed, the test material Santicizer Platinum P-1700 was not considered to be a contact dermal sensitizer in the mouse local lymph node assay.