2-chlorobenzonitrile

Endpoint summary

Description of key information

The LLNA study for 4 -Chlorbenzonitril was taken as read-across source for 2 -Chlorobenzonitril.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05.02.2014 - 18.02.2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Principles of method if other than guideline:

The relative humidity in the animal room was between approximately 23 - 45 % instead of 45 - 65 % for few hours on five days. This deviation to the study plan, however, does not affect the validity of the study.

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA/Ca

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories B.V., Postbus 6174, 5960 AD Horst, The Netherlands
- Age at study initiation:9-10 weeks (at beginning of treatment)
- Weight at study initiation: 19.7 - 23.7 g
- Housing: group housing, cage type: Makrolon Type II (pre-test) / III (main study), with wire mesh top.
- Diet (e.g. ad libitum): 2018C Teklad Global 18 % protein rodent diet (certified), ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 15 days prior to the start of dosing under test conditions after health examination. Only animals without any visible signs of illness were used for the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):22 +/- 2 °C
- Humidity (%): appox. 45-65 % (except for few hours on 5 days, see deviation)

- Photoperiod (hrs dark / hrs light): artificial light 6.00 a.m. - 6.00 p.m.

Vehicle:

dimethylformamide

Concentration:

Pre-Test: 25, 50 % (w/w)
Main-Test:0, 10, 25, 50 % (w/w)

No. of animals per dose:

Pre-Test: one animal per dose
Main-Test: four animals per dose

Details on study design:

see "any other information on material and methods incl. tables"

Positive control substance(s):

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

Statistics:

The mean values and standard deviations of the body weights were calculated.

Positive control results:

Last 10 positive control experiments see table 2 in "any other information on results incl. tables".

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

4 annimals, control group (DMF)

Key result

Parameter:

SI

Value:

0.73

Test group / Remarks:

4 animals, test item 10 % (w/w), diluted in DMF

Key result

Parameter:

SI

Value:

0.51

Test group / Remarks:

4 animals, test item 25 % (w/w), diluted in DMF

Key result

Parameter:

SI

Value:

0.72

Test group / Remarks:

4 animals, test item 50 % (w/w), diluted in DMF

Key result

Parameter:

EC3

Test group / Remarks:

0, 10, 25 and 50 % test item diluted in DMF

Remarks on result:

not determinable

Remarks:

All S.I. values are below the threshold value of 3.

Parameter:

other: disintegrations per minute (DPM)

Test group / Remarks:

0, 10, 25 and 50 % test item diluted in DMF

Remarks on result:

other: see "any other information on results incl. tables"

1. Calculation and Results of Individual Data

Table 1: Calculation and results of individual data.

Test item concentration %	Group	Measurement DPM	Calculation			Result
			DPM-BG^a)[LM1]	number of lymph nodes	DPM per lymph node^b)	S.I.
---	BG I	273	---	---	---	---
---	BG II[LM2]	20	---	---	---	---
0	1	8083	7936.5	8	992.1	1.00
10	2	5957	5810.5	8	726.3	0.73
25	3	4219	4072.5	8	509.1	0.51
50	4	5829	5682.5	8	710.3	0.72

BG = Background; 1 = Control Group; 2-4=  Test Group;

^a)   =  The mean value was taken from the figures BG I and BG II;

^b)    =  Since the lymph nodes of the animals of a dose group were pooled, DPM/node was determined by dividing the measured value by the number of lymph nodes pooled

The EC3 value could not be calculated, since all S.I. values are below the threshold value of 3.

2. Viability / Mortality

No deaths occurred during the study period.

3. Clinical Signs

No symptoms of local skin irritation at the ears of the animals and no signs of systemic toxicity were observed during the study period.

4. Body Weights

The body weight of the animals, recorded prior to the first application and prior to treatment with³HTdR, was within the range commonly recorded for animals of this strain and age.

5. Positive Control Data

Table 2: The last 10 positive control experiments.

Positive Control Substance	Date	Concentration / Vehicle	S.I. value
α-Hexylcinnamaldehyde	October 2013	25% in acetone:olive oil (4+1, v/v)	5.8
	April 2013		5.9
	October 2012		5.7
	April 2012		3.7
	February 2012		4.7
	January 2012		10.8
	January 2012		7.1
	December 2011		5.9
	November 2011		5.3
	October 2011		6.1

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test item 4-Chlorobenzonitrile was not a skin sensitiser under the test conditions of this study accroding to OECD 429 ("Skin Sensitisation: Local Lymph Node Assay").

Executive summary:

In a study according to OECD 429 ("Skin Sensitisation: Local Lymph Node Assay") 4-Chlorobenzonitrile formulated in DMF was assessed for its possible skin sensitising potential. The test was performed in mice using test item concentrations of 10, 25, and 50 % (w/w). The animals did not show any signs of systemic toxicity or local skin irritation during the course of the study and no cases of motality were observed. Stimulation Indices (S.I.) of 0.73, 0.51, and 0.72 were determined with the test item at concentrations of 10, 25, and 50 % (w/w) in DMF, respectively.

Therefore the test item 4-Chlorobenzonitrile was not a skin sensitiser under the test conditions of this study.

Reference 2

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
[Please provide information for all of the points below. Indicate if further information is included as attachment to the same record, or elsewhere in the dataset (insert links in 'Cross-reference' table)]

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
[Describe why the read-across can be performed (e.g. common functional group(s), common precursor(s)/breakdown product(s) or common mechanism(s) of action]
Source and target substance are chlorine substituted benzonitriles.
Both substances show a similar toxiscity and both substances are not skin irritant.
QSAR calculation of skin sensitizing properties is negative for both subsances.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
[Provide here, if relevant, additional information to that included in the Test material section of the source and target records]

3. ANALOGUE APPROACH JUSTIFICATION
[Summarise here based on available experimental data how these results verify that the read-across is justified]
Based on the QSAR calculations and the experimental data, 4-chlorobenzonitrile can be taken as read-across source for 2-chlorobenzonitrile.

4. DATA MATRIX

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

4 annimals, control group (DMF)

Key result

Parameter:

SI

Value:

0.73

Test group / Remarks:

4 animals, test item 10 % (w/w), diluted in DMF

Key result

Parameter:

SI

Value:

0.51

Test group / Remarks:

4 animals, test item 25 % (w/w), diluted in DMF

Key result

Parameter:

SI

Value:

0.72

Test group / Remarks:

4 animals, test item 50 % (w/w), diluted in DMF

Key result

Parameter:

EC3

Test group / Remarks:

0, 10, 25 and 50 % test item diluted in DMF

Remarks on result:

not determinable

Remarks:

All S.I. values are below the threshold value of 3.

Parameter:

other: disintegrations per minute (DPM)

Test group / Remarks:

0, 10, 25 and 50 % test item diluted in DMF

Remarks on result:

other: see "any other information on results incl. tables"

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test item 2-Chlorobenzonitrile was not a skin sensitiser under the test conditions of this study accroding to OECD 429 ("Skin Sensitisation: Local Lymph Node Assay").

Executive summary:

In a study according to OECD 429 ("Skin Sensitisation: Local Lymph Node Assay") 2-Chlorobenzonitrile formulated in DMF was assessed for its possible skin sensitising potential. The test was performed in mice using test item concentrations of 10, 25, and 50 % (w/w). The animals did not show any signs of systemic toxicity or local skin irritation during the course of the study and no cases of motality were observed. Stimulation Indices (S.I.) of 0.73, 0.51, and 0.72 were determined with the test item at concentrations of 10, 25, and 50 % (w/w) in DMF, respectively.

Therefore the test item 2-Chlorobenzonitrile was not a skin sensitiser under the test conditions of this study.

Reference 3

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

an in vitro skin sensitisation study does not need to be conducted because adequate data from an in vivo skin sensitisation study are available

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Justification for classification or non-classification

According to CLP regulation 2 -Chlorobenzonitrile is not classified as skin sensitizer.