Reaction mass of 3,4,5-trichlorophthalic acid, strontium salt and 3,4,6-trichlorophthalic acid, strontium salt and 3,4-dichlorophthalic acid, strontium salt and 3,5-dichlorophthalic acid, strontium salt and 3,6-dichlorophthalic acid, strontium salt and 3-chlorophthalic acid, strontium salt and 4,5-dichlorophthalic acid, strontium salt and 4-chlorophthalic acid, strontium salt

Endpoint summary

Description of key information

The skin sensitisation potential of strontium dichlorophthalate was assessed in two in vitro skin sensitisation assays conducted according to OECD 442D and OECD 442E.

In the first study conducted according to OECD 442E, the sensitisation potential of the substance was assessed based on the activation of dendritic cells using the in vitro U937 cell line activation Test (U-Sens™) assay. In the second study conducted according to OECD 442D, the skin sensitisation potential of the target substance was assessed based on the activation of keratinocytes using the in vitro KeratinoSens cell line.

Based on the results of both studies, strontium dichlorophtalate is not considered to be a skin sensitiser.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2019-10-02 to 2019-11-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 442D (In Vitro Skin Sensitisation: ARE-Nrf2 Luciferase Test Method)

Version / remarks:

adopted June 2018

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

activation of keratinocytes

Justification for non-LLNA method:

The induction of the Keap1-Nrf2-ARE signalling pathway by small electrophilic substances such as skin sensitizers was reported by several studies and represents the second key event of the skin sensitisation process as described by the AOP. Therefore, the KeratinoSens™ assay is considered relevant for the assessment of the skin sensitisation potential of chemicals.

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: Dynamit Nobel GmbH Explosivstoff- und Systemtechnik; Batch: WE: 50352354
- Expiration date of the lot/batch: 28 November 2019
- Purity test date: 2 September 2019

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: No correction was made for the composition/purity of the test item. In the main experiments the test item was suspended in DMSO at 200 mM (white suspension). From this stock 11 spike solutions in DMSO were prepared (2-fold dilution series). The stock and spike solution were diluted 25-fold with exposure medium. These solutions were diluted 4-fold with exposure medium in the assay resulting in final test concentrations of 2000, 1000, 500, 250, 125, 63, 31, 16, 7.8, 3.9, 2.0 and 0.98 μM (final concentration DMSO of 1%). All concentrations of the test item were tested in triplicate.

Details on the study design:

Skin sensitisation (In vitro test system) - Details on study design:

TEST SYSTEM
A transgenic cell line having a stable insertion of the luciferase reporter gene under the control of the ARE-element is used (e.g. the KeratinoSens™ cell line). The KeratinoSens™ cell line was generated by and obtained from Givaudan (Duebendorf, Switzerland). Upon receipt, cells are propagated (e.g. 2 to 4 passages) and stored frozen as a homogeneous stock. Cells from this original stock can be propagated up to a maximum passage number from the frozen stock (i.e. 25) and are employed for routine testing using the appropriate maintenance medium.

RATIONALE
In the interest of sound science and animal welfare, a sequential testing strategy is recommended to minimize the need of in vivo testing. One of the validated in vitro skin sensitization tests is the KeratinoSensTM assay, which is recommended in international guidelines (e.g. OECD 442D).

CELL CULTURE

Basic medium:
Dulbecco’s minimal (DMEM glutamax) supplemented with 9.1% (v/v) heat-inactivated (56°C; 30 min) fetal calf serum (Life Technologies, Bleiswijk, The Netherlands).

Maintenance medium:
Dulbecco’s minimal (DMEM glutamax) supplemented with 9.1% (v/v) heat-inactivated (56°C; 30 min) foetal calf serum and geneticin (500 μg/mL).

Exposure medium:
Dulbecco’s minimal (DMEM glutamax) supplemented with 1% (v/v) heat-inactivated (56°C; 30 min) foetal calf serum.

Environmental conditions:
All incubations were carried out in a controlled environment, in which optimal conditions were a humid atmosphere of 80 - 100% (actual range 51 – 94 %), containing 5.0 ± 0.5% CO2 in air in the dark at 37.0 ± 1.0°C (actual range 35.1 – 36.7°C). Temperature and humidity were continuously monitored throughout the experiment. The CO2 percentage was monitored once on each working day. Temporary deviations from the temperature and humidity occurred due to opening and closing of the incubator door. Based on laboratory historical data these deviations are considered not to affect the study integrity.

SUBCULTURING

Cells were subcultured upon reaching 80-90% confluency. To maintain the integrity of the response, the cells were grown for more than one passage from the frozen stock and were not cultured for more than 25 passages from the frozen stock (P+25).

EXPERIMENTAL DESIGN

Plating of cells:
For testing, cells were 80-90% confluent. One day prior to testing cells were harvested and distributed into 96-well plates (10,000 cells/well) in basic medium. For each repetition, three replicates were used for the luciferase activity measurements, and one parallel replicate used for the MTT cell viability assay. The cells were incubated overnight in the incubator. The passage number used was P+9 in experiment 1 and P+13 in experiment 2.

Treatment of cells:
The medium was removed and replaced with fresh culture medium (150 μL culture medium containing serum but without Geneticin) to which 50 μL of the 25-fold diluted test chemical and control items were added. Three wells per plate were left empty (no cells and no treatment) to assess background values. The treated plates were covered with foil and then incubated for about 48 hours ± 1 h at 37±1.0°C in the presence of 5% CO2. In total 2 valid experiments were performed.

Luciferase Activity Measurement:
The Steady-Glo Luciferase Assay Buffer (10 mL) and Steady-Glo Luciferase Assay Substrate (lyophilized) from Promega (Leiden, The Netherlands) were mixed together. The assay plates were removed from the incubator and the medium is removed. Then 200 μL of the Steady-Glo Luciferase substrate solution (prior to addition 1:1 mixed with exposure medium) was added to each well. The plates were shaken for at least 5 minutes at room temperature. Plates with the cell lysates were placed in the TECAN Infinite® M200 Pro Plate Reader to assess the quantity of luciferase (integration time two seconds).

Cytotoxicity Assessment:
For the KeratinoSensTM cell viability assay, medium was replaced after the 48 hour exposure time with fresh medium containing MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide, Thiazolyl blue tetrazolium bromide; CAS No. 298-93-1; Sigma, Zwijndrecht, The Netherlands) and cells were incubated for 3 - 4 hours at 37°C± 1.0°C in the presence of 5% CO2. The MTT medium was then removed and cells were lysed overnight by adding 10% SDS solution (Sigma, Zwijndrecht, The Netherlands) to each well. After shaking, the absorption was measured at 570 nm with the TECAN Infinite® M200 Pro Plate Reader.

Positive control results:

The positive control Ethylene dimethacrylate glycol caused a dose related induction of the luciferase activity. The Imax was 2.22 and the EC1.5 55 μM in experiment 1 and in experiment 2 the Imax was 2.24 and the EC1.5 75 μM.

Run / experiment:

other: Mean of Experiment 1 and 2

Parameter:

other: max. luciferase activity (Imax) induction

Value:

1.23

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Key result

Run / experiment:

other: Experiment 1

Parameter:

other: max. luciferase activity (Imax) induction

Value:

1.2

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Remarks:

No significant luciferase induction >1.5-fold in tested concentration range; no EC1.5 value could be calculated

Key result

Run / experiment:

other: experiment 2

Parameter:

other: max. luciferase activity (Imax) induction

Value:

1.26

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Remarks:

No significant luciferase induction >1.5-fold in tested concentration range; no EC1.5 value could be calculated

Other effects / acceptance of results:

DEMONSTRATION OF TECHNICAL PROFICIENCY:
Two independent experiments were performed. The cells were in these experiments incubated with the test item in a concentration range of 0.98 – 2000 μM (2-fold dilution steps) for 48 hours ± 1 h. The activation of the ARE-dependent pathway was assessed by measuring the luminescence induction compared to the vehicle control. In addition, the viability was assessed with an MTT assay.
For every concentration showing >1.5 fold luciferase activity induction, statistical significance (p <0.05) was calculated using a two-tailed Student’s t-test comparing the luminescence values for the three replicated samples with the luminescence values in the solvent (negative) control wells.
The lowest concentration with >1.5 fold luciferase activity induction was the value determining the EC1.5 value. It was checked in each case whether this value was below the IC30 value, indicating that there was less than 30% reduction on cellular viability at the EC1.5 determining concentration.

ACCEPTANCE OF RESULTS:
Both tests passed the acceptance criteria:
- The luciferase activity induction obtained with the positive control, Ethylene dimethacrylate glycol, was statistically significant above the threshold of 1.5-fold in at least one concentration.
- The EC1.5 of the positive control was within two standard deviations of the historical mean (55 μM and 75 μM in experiment 1 and 2, respectively). A dose response was observed and the induction at 250 μM was higher than 2-fold (2.22-fold and 2.24-fold in experiment 1 and 2, respectively).
- Finally, the average coefficient of variation of the luminescence reading for the vehicle (negative) control DMSO was below 20% (12% in experiment 1 and 2).
Overall it is concluded that the test conditions were adequate and that the test system functioned properly.

For individual results see tables in box "Any other information on results incl. tables".

Table 1: Overview Luminescence Induction and Cell Viability of Strontium dichlorophthalate in Experiment 1 and 2

Concentration (µM)	0.98	2.0	3.9	7.8	16	31	63	125	250	500	1000	2000
Exp 1 luminescence	1.13	1.20	1.14	1.16	1.12	1.11	1.10	0.99	0.93	0.91	0.89	0.67
Exp 1 viability (%)	110.2	101.5	97.2	99.8	98.5	96.8	94.7	97.2	90.9	84.3	72.6	54.1
Exp 2 luminescence	1.22	1.26	1.06	1.15	1.16	1.15	1.01	0.88	0.92	0.74	0.59	0.56
Exp 2 viability (%)	112.6	113.3	107.2	105.3	111.9	108.4	104.1	97.9	96.7	86.1	78.2	64.0

Table 2: Overview Luminescence Induction and Cell Viability Positive Control EDMG in Experiment 1 and 2

Concentration (µM)	7.8	16	31	63	125	250
Exp 1 luminescence	1.09	1.18	1.28	1.57***	1.85***	2.22***
Exp 1 viability (%)	112.6	108.6	102.3	104.2	99.4	98.6
Exp 2 luminescence	1.13	1.15	1.20	1.44	1.74***	2.24***
Exp 2 viability (%)	115.7	122.6	115.8	108.2	106.2	95.3

*** p<0.001 Student’s t test

Table 3: Overview EC_1.5, I_max, IC₃₀and IC₅₀Values

	EC1.5 (µM)	Imax	IC30 (µM)	IC50 (µM)
Test item Experiment 1	NA	1.20	1140	NA
Test item Experiment 2	NA	1.26	1576	NA
Pos Control Experiment 1	55	2.22	NA	NA
Pos Control Experiment 2	75	2.24	NA	NA

NA = Not applicable

Interpretation of results:

GHS criteria not met

Remarks:

Test item is considered a non-sensitiser

Conclusions:

In this study under the given conditions the test item did not induce the luciferase activity in the transgenic KeratinoSens™ cell line in at least two independent experiment runs. Therefore, test item can be considered to be a non-sensitizer.

Executive summary:

In a dermal sensitisation study conducted according to OECD 442D with strontium dichlorophthalate in DMSO, the sensitisation potential of the test item was assessed on the basis of the activation of keratinocytes using the in vitro KeratinoSens™. Cells were incubated with the test item for 48 h at 37 °C and later checked for luciferase activity.

Sensitisation was scored by measuring maximum luciferase activity induction (Imax), cell viability and EC1.5. For both Experiment 1 and 2, Imax was less than a 1.5 fold increase and no biologically relevant induction of the luciferase activity was measured at any of the test concentrations in both experiments, thus the EC1.5 could not be calculated.

Therefore, in this study, the test item strontium dichlorophthalate is considered to be a skin non-sensitiser.

Reference 2

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2019-10-24 to 2019-11-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD 442E

Version / remarks:

adopted 25 June 2018

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

activation of dendritic cells

Justification for non-LLNA method:

The correlation of upregulation of immunological relevant cell surface markers with the skin sensitising potential of a chemical has been reported and represents the third key event in the skin sensitisation process as described by the AOP. This method that measures the markers of DC activation, based on DC-like cell line THP-1 is considered relevant for the assessment of the skin sensitisation potential of chemicals. Moreover, this test method is able to detect chemicals that cause skin sensitisation and allows hazard identification.

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: Dynamit Nobel GmbH Explosivstoff- und Systemtechnik; Batch: WE: 50352354
- Expiration date of the lot/batch: 28 November 2019
- Purity test date: 2 September 2019

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: No correction was made for the composition/purity of the test item. In the main experiments the test item was dissolved in complete medium at 0.4 mg/mL. The stock was diluted to a final test concentration of 200, 100, 50, 20, 10 and 1 μg/mL in experiment 1 and 2 and of 200, 100, 50 and 20 μg/mL in experiment 3 in the 96-well plate.

Details on the study design:

TEST SYSTEM
Test System: U937 human monocytes
Justification: Inducible CD86-expressing cells
Source: ATCC (American Type Culture Collection, Virginia, USA). ATCC no.: CRL-1593.2TM
Stock cultures of these cells are stored in the freezer (-150°C). Cells were used after an acclimatisation period of approximately 8 days after thawing and were not sub-cultured more than 21 times. Once a year the cell line is checked for infection with a mycoplasma detection test.
Each batch of cells received from a supplier are submitted to a qualification process to guarantee their suitability (spontaneous CD86 level) for the test by comparison with the historical data or data from the literature.

Rationale:
In the interest of sound science and animal welfare, a sequential testing strategy is
recommended for skin sensitization to minimize the need of in vivo testing. One of the validated in vitro skin sensitization tests is the U-SENSTM assay, which is recommended in international guideline (e.g. OECD).

CELL CULTURE

Cell culture medium:
Stock and treatment cultures were performed in RPMI-1640 medium supplemented with 10% (v/v) heat-inactivated (56°C; 30 min) foetal calf serum (FCS), L-glutamine (2 mM), penicillin/streptomycin (50 U/mL and 50 µg/mL respectively).

Environmental conditions:
All incubations were carried out in a humid atmosphere of 80 - 100% (actual range 49 – 94%) containing 5.0 ± 0.5% CO2 in air in the dark at 37.0 ± 1.0°C (actual range 35.7 – 36.7°C). Temperature and humidity were continuously monitored throughout the experiment. The CO2 percentage was monitored once on each working day. Temporary deviations from the temperature, humidity and CO2 percentage may occur due to opening and closing of the incubator door. Based on laboratory historical data these deviations are considered not to affect the study integrity.

EXPERIMENTAL DESIGN

Plating of Cells:
Cultures were initiated in 96-well plates using 100 μL/well of a cell suspension adjusted at 5.0 x 10^5 viable cells/mL. Cell viability was > 90%. All assays were performed using two replicate culture-wells for the test item. One replicate was dedicated to the nonspecific IgG1 binding and the other one to the CD86 binding. Three replicates of untreated control (RPMI), vehicle control (in case of DMSO as vehicle), negative (lactic acid; LA) and positive (2,4,6-Trinitrobenzenesulfonic acid; TNBS) controls were tested.

Number of experiments:
Three experiments were conducted per test item to demonstrate reproducibility of the results and conclusion.

Treatment of Cells:
Cells are treated for 45 ± 3 hours with the selected doses or controls (100 μL). The test item was in the first experiment evaluated up to 200 μg/mL using six doses: 1.0, 10, 20, 50, 100 and 200 μg/mL.
In the second experiment cells were treated with six selected doses of test item. At least 2 concentrations were common with the previous experiment. The concentrations selected in the second experiment were 1.0, 10, 20, 50, 100 and 200 μg/mL.
In the third experiment cells were treated with four selected doses of test item. At least 2 concentrations were common with the previous experiment. The concentrations selected in the second experiment were 20, 50, 100 and 200 μg/mL.
In all experiments, an untreated control (RPMI), vehicle control (in case of DMSO as vehicle) and the positive (TNBS) and negative control (LA) items were included. The final volume in the wells was 200 μL.

Precipitate evaluation:
After 45 ± 3 hours of exposure, wells were checked for precipitate.

Cell antibodies staining for IgG1 and CD86:
Cultures were transferred into V-shaped 96-well plates. The cells were separated from the exposure medium by centrifugation (5 min, 200 g). The supernatant was discarded, and cells were rinsed once with 100 μL/well Phosphate Buffered Saline (PBS) containing 5% FCS. After a second centrifugation step (5 min, 200 g) 100 μL/well of staining buffer (PBS containing 5% FCS) was applied to the cells.

FITC-conjugated antibodies were used for both IgG1 and CD86 staining:
- Mouse IgG1 of unknown specificity, for isotypic control (#555748; BD, Amsterdam, The Netherlands)
- Human CD86 specific mouse IgG1 (#555657; BD, Amsterdam, The Netherlands)

The cells were transferred into new V-shaped 96-well plates (keeping the same plate template) containing 5 μL/well of the appropriate antibody (1:1 diluted in PBS) and placed refrigerated in the dark for 30 minutes. After this staining period, the cells were rinsed twice with a mixture of PBS/FCS and once in PBS alone and re-suspended in 90 μL of PBS.

Flow cytometry method:
Acquisition: Just before acquisition, 5 μL of a 0.5 μg/mL propidium iodide (PI) solution was added to each well. The size (FSC) was set linear and the granularity (SSC) parameter was set to logarithmic scale and a R1 region was defined in which approximately 10,000 events were acquired for each culture. The acquisition parameters remained unchanged for the acquisition of all the wells. For the acquisition the BD FACSCanto™ flow cytometer was used and for further analysis BD FACSDiva™ software was used.

Analysis: All analysis parameters were set on the RPMI wells for IgG1 and remained unchanged, for the analysis of all the other wells. The P1 region was adjusted if necessary, in a SSC (X-axis) and FSC (Y-axis) plot. The P2 region was defined for the PI negative cells among P1 in a histogram with counts (Y-axis) and PI fluorescence (X-axis). The amount of cytotoxicity was analysed as percentage of cells in P2. The P2 region was then plotted in a Dot-plot as fluorescence (X-axis) and SSC (Y-axis) and a quadrant was placed according acceptability criterion b. The percentage of cells in the UR quadrant was used to calculate the stimulation index.

Colour interferences: There is colour interference in the IgG1 evaluation when the X Median of the FITC-fluorescence in the UL Quad is 50% higher than the X Median fluorescence of the vehicle control IgG1 well (IgG1 X Median S.I. ≥ 150%).

Positive control results:

The positive control (TNBS) showed a S.I. ≥ 914% in all wells and was non-cytotoxic at all concentrations (cell viability ≥ 70%) in experiment 1 and in experiment 2 a S.I. ≥ 854% in all wells and was non-cytotoxic at all concentrations (cell viability ≥ 70%).

Run / experiment:

other: 1

Parameter:

other: CD86 upregulation / at highest tested concentration

Value:

86

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Run / experiment:

other: 2

Parameter:

other: CD86 upregulation / at highest tested concentration

Value:

99

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Run / experiment:

other: 3

Parameter:

other: CD86 upregulation / at highest tested concentration

Value:

80

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:

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes
- Range of historical values if different from the ones specified in the test guideline: see table 3 in box "Any other information on results incl. tables"

Table1: Overview Stimulation index of CD86 and Cell Viability in Experiment 1, 2 and 3 of Strontium dichlorophthalate

Test items	Dose	% Viability (Mean)*			CD86-IgG1 S.I.			Colour Interference S.I.
	(µg/mL)	Experiment			Experiment			Experiment
		1	2	3	1	2	3	1	2	3
Strontium dichlorophthalate
	1	100	100	-	121	109	-	101	105	-
	10	100	100	-	103	126	-	104	105	-
	20	100	100	100	138	128	105	103	106	99
	50	100	100	99	117	136	105	102	97	95
	100	100	100	99	93	111	105	97	101	96
	200	100	100	99	86	99	80	92	100	91

Table 2: Overview Stimulation index of CD86 and Cell Viability in Experiment 1, 2 and 3 of the Positive, Negative and Vehicle Control

Controls	% Viability (Mean)*			CD86-IgG1 S.I.*
	Experiment			Experiment
	1	2	3	1	2	3
LA1	100	100	100	93	54	80
LA2	100	100	100	90	86	60
LA3	100	100	100	103	94	40
TNBS1	100	100	99	914	874	755
TNBS2	100	100	99	934	854	745
TNBS3	100	100	99	1017	854	1150
	IgG1 value (%)			CD86 basal expression (%)			CD86-IgG1 expression (%)
	Experiment			Experiment			Experiment
	1	2	3	1	2	3	1	2	3
RPMI1	0.9	0.91	0.6	3.1	2.41	2.6	2.2	1.5(1)	2.0
RPMI2	1.1	0.7	0.7	4.3	4.1	2.7	3.2	3.4	2.0
RPMI3	1.0	0.8	0.8	4.3	5.5	2.8	3.3	4.7	2.0
RPMI Mean Viability				100%	100%	99%
RPMI Drift				22%	92%	0%
LA Drift				13%	33%	-43%

* Red values are either below 70% viability, above 150 S.I.

(1) Excluded from analysis, value >25% from mean

Table 3: Historical Control Data for the USENS^TM Assay (November 2017 to December 2018)

	Positive control		Negative control
	S.I. (%)	Viability (%)	S.I. (%)	Viability (%)
Range (Mean ± 2 * SD)	239 – 631	90 – 103	58 – 129	95 – 101
Mean	435	97	94	98
SD	151	3.4	18	1.5
n	286	286	286	286

SD = Standard deviation

n = Number of observations

Interpretation of results:

GHS criteria not met

Remarks:

the test item is considered to be a non-sensitiser

Conclusions:

In this study under the given conditions the test item strontium dichlorophthalate did not upregulate the cell surface markers in two independent experiment runs. Therefore, the test item can be considered to be a non-sensitiser in this test.

Executive summary:

In a skin sensitisation study conducted according to OECD 442E with strontium dichlorophthalate in DMSO, the sensitisation potential of the test item was assessed on the basis of the activation of dendritic cells using the U937 cell line activation Test (U-Sens™) assay. Cells were incubated with the test item for 24 h at 37 °C and later checked for cell viability and expression of CD86 cell surface markers.

Sensitisation was scored by measuring cell viability and checking the expression of cell surface markers. The test item showed no toxicity (No CV70 value) and no biologically relevant induction of the CD86 activity (No EC₁₅₀value) was measured at any of the test concentrations in all experiments. The test item is classified as negative in the U-Sens™ assay since negative results (< 150% increase) were observed at all test concentrations with a cell viability of >70% compared to the vehicle control. In conclusion, atrontium dichlorophthalate is classified as negative under the experimental conditions described in this study.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In two in vitro skin sensitisation studies conducted according to OECD 442D and OECD 442E, the substance strontium dichlorophthalate was tested for skin sensitisation. Based on the results of both studies, no classification of strontium dichloropthalate for skin sensitisation is warranted.