Cinnamonitrile

Endpoint summary

Description of key information

Skin sensitization:

Skin sensitization potential of Cinnamonitrile was evaluated by Local Lymph Node Assay (LLNA) The LLNAs were conducted according to the method described inOECD Guideline 429. No discription of the effects observed during the study and observation phase have been reported.

The EC3 value obtained from LLNA assay performed to assess the sensitizing potential of cinnamyl nitrile was > 2500 microgram/sq cm. Based on this value, cinnamyl nitrile can be considered to be sensitizing to skin.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

Data is from peer reviewed journals

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

To evaluate the skin sensitization potential of Cinnamonitrile by Mouse Local Lymph Node Assay

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Specific details on test material used for the study:

IUPAC: Cinnamonitrile
CAS No:1885-38-7
EC No: 217-552-5
Commen name: Cinnamyl Nitrile
Molecular formula : C9H7N
Molecular weight : 129.161 g/mol
substance type: organic
InChI: 1S/C9H7N/c10-8-4-7-9-5-2-1-3-6-9/h1-7H/b7-4+
Smiles :N#C\C=C\c1ccccc1
Physical state: colorless- yellow liquid

Vehicle:

other: 1:3 ethanol :diethyl phthalate.

Concentration:

25 µl (Each group received one of five test concentrations prepared as a w/v%.)

No. of animals per dose:

Total=5

Details on study design:

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: EC 3 value
TREATMENT PREPARATION AND ADMINISTRATION: Groups of female CBA/CA mice were dosed topically on the dorsum of each ear with 25 µl of test fragrance in 1:3 ethanol: diethyl phthalate.

Each group received one of five test concentrations prepared
as a w/v%.

Positive control substance(s):

other: Concurrent vehicle control used- 1:3 ethanol:diethyl phthalate

Key result

Parameter:

EC3

Value:

> 2 500

Remarks on result:

other: skin sensitizing

Cellular proliferation data / Observations:

The stimulation index (SI) values were calculated for each dose level. An SI of 3 or more was considered to give a positive response.

Interpretation of results:

other: Skin sensitizing

Conclusions:

The EC3 value obtained from LLNA assay performed to assess the sensitizing potential of cinnamyl nitrile was > 2500 microgram/sq cm. Based on this value, cinnamyl nitrile can be considered to be sensitizing to skin.

Executive summary:

Skin sensitization potential of Cinnamonitrile was evaluated by Local Lymph Node Assay (LLNA) The LLNAs were conducted according to the method described inOECD Guideline 429. Groups of female CBA/CA mice (n= 5) were dosed topically on the dorsum of each ear with 25 ml of test material in 1:3 ethanol :diethyl phthalate. Each group received one of five test concentrations prepared as a w/v%. A concurrent vehicle control group was similarly treated with 1:3 ethanol: diethyl phthalate. Dosing occurred daily for three consecutive days. The animals received no treatment for two days and on the sixth day after the first application, all mice were injected intravenously via the tail vein with 250 ml of phosphate buffered saline containing 20 µCi of radiolabelled methyl thymidine (3HTdR). Five hours later, the mice were euthanized and the draining auricular lymph nodes were excised and pooled . Suspensions of the lymph node cells were prepared by mechanical disaggregation through 200-mesh stainless steel gauze. The cell suspensions were washed three times with phosphate buffered saline and precipitatedovernight at 4 °C with 5% w/v trichloroacetic acid (TCA). The samples were then pelleted by centrifugation. The cells were resuspended in 1ml of TCA and transferred to scintillation vials containing 10 ml of scintillation fluid. The incorporation of 3HTdR was measured by β- scintillationcounting and expressed as disintegrations per minute (dpm) per lymph node.

No description of the effects observed during the study and observation phase have been reported.

The EC3 value obtained from LLNA assay performed to assess the sensitizing potential of cinnamyl nitrile was > 2500 microgram/sq cm. Based on this value, cinnamyl nitrile can be considered to be sensitizing to skin.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Skin sensitization:

Various studies were investigated to ascertain the dermal sensitization potential of Cinnamyl nitrile. The studies are based on the in-vivo experiments in mice, rabbits, guinea pigs and human volunteers.

Skin sensitization potential of Cinnamonitrile was evaluated (Cutaneous and ocular toxicology, 34, no. 4, (2015), 298-302) by performing a Local Lymph Node Assay (LLNA). The assay was conducted according to the method described in OECD Guideline 429. Groups of female CBA/CA mice (n= 5) were dosed topically on the dorsum of each ear with 25 ml of test material in 1:3 ethanol :diethyl phthalate. Each group received one of five test concentrations prepared as a w/v%. A concurrent vehicle control group was similarly treated with 1:3 ethanol: diethyl phthalate. Dosing occurred daily for three consecutive days. The animals received no treatment for two days and on the sixth day after the first application, all mice were injected intravenously via the tail vein with 250 ml of phosphate buffered saline containing 20 µCi of radiolabelled methyl thymidine (3HTdR). Five hours later, the mice were euthanized and the draining auricular lymph nodes were excised and pooled . Suspensions of the lymph node cells were prepared by mechanical disaggregation through 200-mesh stainless steel gauze. The cell suspensions were washed three times with phosphate buffered saline and precipitated overnight at 4 °C with 5% w/v trichloroacetic acid (TCA). The samples were then pelleted by centrifugation. The cells were resuspended in 1ml of TCA and transferred to scintillation vials containing 10 ml of scintillation fluid. The incorporation of 3HTdR was measured by β- scintillation counting and expressed as disintegrations per minute (dpm) per lymph node.

No discription of the effects observed during the study and observation phase have been reported.

The EC3 value obtained from LLNA assay performed to assess the sensitizing potential of cinnamyl nitrile was > 2500 microgram/sq cm. Based on this value, cinnamyl nitrile can be considered to be sensitizing to skin.

Human Repeat Insult Patch Test was performed (Cutaneous and ocular toxicology, 34, no. 4, (2015), 298-302) to evaluate the skin sensitization potential of cinnamyl nitrile on 100 human volunteers. Each HRIPT study received approval from an independent ethical review committee (IRB institutional review board) prior to its initiation. During the induction phase an occlusive webril/adhesive patch (25mm Hill Top Chamber System) was used. 0.3 ml of the test material in 1:3 ethanol:diethyl phthalate (vehicle) was applied to each patch. The test material was allowed to volatilize for at least 15 min but no longer than 40 min prior to application to the skin. The left side of the back was used for the test area during the induction phase. Patches remained in place and were kept dry for approximately 24 h, after which time they were removed. A 24 hour rest period was given, during which no test material was applied. For alternate days test sites were observed and scored. The identical test site was then retreated until nine induction applications were completed over a period of approximately 3 weeks. A rest period of approximately 2 weeks followed the last induction patch. No test materials were applied during the rest period. At the challenge phase, the original induction test sites were observed and each subject queried as to whether any reaction had been experienced during the rest period. The untreated right side of the back was used for the for the challenge phase. Patches were applied as in the induction phase and held in place for 24 h after which time they were removed and the challenge site scored. The original test sites were also observed. Scoring of the test sites was also carried out at 48, 72 and 96 h.

No description of the effects observed during the study and observation phase have been reported.

The NOEL value obtained from HRIPT assay performed to assess the sensitizing potential of cinnamyl nitrile was 1063 microgram/sq cm. Based on this value, cinnamyl nitrile can be considered to be sensitizing to skin.

Similarly the human volunteers were also evaluated (Cutaneous and ocular toxicology, 34, no. 4, (2015), 298-302) for skin sensitization potential in a Human Maximization test. Cinnamyl nitrile was applied in petrolatum under occlusion to the forearms or back of all subjects for five alternate-day 48 h periods. Patch sites were pre-treated for 24 h with 10% aqueous sodium lauryl sulfate (SLS) under occlusion. Following a 10–14 day rest period, challenge patches were applied under occlusion to a fresh forearm site for 48 h. Challenge applications were preceded by 30–60 min SLS treatment. Reactions were read at patch removal and again at 96 h after the initiation of application. Scoring of the test sites was also carried out at 48, 72 and 96 h post-patching using the following scoring scale: 0 = no visible reaction; +/-= faint, minimal erythema; 1= erythema; 2= intense erythema, induration; 3= intense erythema, induration, vesicles; 4= severe reaction with erythema, induration, vesicles, pustules.

No discription of the effects observed during the study and observation phase have been reported.

The LOEL value obtained from HMT assay performed to assess the sensitizing potential of cinnamyl nitrile was 1938 microgram/sq cm. Based on this value, cinnamyl nitrile can be considered to be sensitizing to skin.

In an another Local lymph node assay (LLNA) summarized in Scientific Committee on Consumer Safety adopted this opinion at its 15th plenary meeting 2012 , cinnamyl nitrile was applied in the concentrations of 2.5, 5.0, 10.0,25.0, 50.0 % (w/v) in 1:3 EtOH:DEP as vehicle to the skin of 4 mice.

No description of the effects observed during the study and observation phase have been reported.

The EC3 value obtained for cinnamyl nitrile was > 2500 microgram/sq cm. Systemic sensitization was reported in 25% and 50% concentration.

Based on this value, cinnamyl nitrile can be considered to be sensitizing to skin.

Cinnamyl nitrile was also tested in a human maximization assay summarized in Food and Cosmetics Toxicology, Volume 14, Supplement, 1976, Pages 721-722; to assess the dermal sensitization potential. Cinnamyl nitrile 4% in petrolatum was applied to the skin of 25 human volunteers and observed for signs of dermal sensitization (duration not mentioned).Cinnamyl nitrile failed to cause any dermal reactions in the human volunteers. Hence, Cinnamyl nitrile was considered to be not sensitizing to skin.

 

Eventhough this study claims that cinnamyl nitrile is not a skin sensitizer, but remaining results in guinea pigs and humans show enough evidence regarding the sensitizing potential of cinnamyl nitrile. Hence, the above study can be negated and Cinnamyl nitrile can be considered to be a potential skin sensitizer. It can be classified as a “Skin Sensitizer” as per CLP regulation.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the available data for the target as well as it read across substances and applying the weight of evidence approach,it can be concluded that Cinnamyl nitrile was sensitizing to skin. It can be classified under the category “Skin sensitizing” as per CLP regulation.