C16-18-(even numbered)-alkyl fatty acid, compound with C16-18-(even numbered)-alkylamine

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 December 2012 - 25 March 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Compliant to GLP and testing guidelines; adequate consistence between data, comments and conclusions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The test item tested is a surfactant. The Local Lymph Node Assay has been shown to be inappropriate for assessment of skin sensitization of this chemical class, in particular in the following publications:
. D. Basketter et al. (2009) Application of a weight of evidence approach to assessing discordant sensitization dataset: implications for Reach. Regular toxicology and Pharmacology, 55: 90-96,
. R. Kreiling et al. (2008) Comparison of the sensitizing potential of unsaturated compound as assessed by the murine Local Lymph Node Assay (LLNA) and the guinea pig maximization test (GPMT), Food and Chemical Toxicology, 46: 1896-1904.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: breeder: Charles River Laboratories France, L’Arbresle, France
- Age/weight at study initiation: the animals were 1 to 2 months old and the males had a mean body weight of 410 g (range: 293 g to 474 g) and the females had a mean body weight of 360 g (range: 252 g to 430 g)
- Fasting period before study: no
- Housing: the animals of the preliminary tests were individually housed in polycarbonate cages with stainless steel lids and the animals of the main test were group housed by five from the same sex and group in stainless steel cages
- Diet: 106 pelleted diet (free access)
- Water: tap water filtered with a 0.22 µm filter (free access)
- Acclimation period: at least 5 days before the beginning of the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): approximately 12 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12 h/12 h.

IN-LIFE DATES: 31 January 2013 to 25 March 2013.

Route:

other: intradermal and cutaneous

Vehicle:

other: corn oil (intradermal injection and induction application) and propylene glycol (challenge application)

Concentration / amount:

Induction phase:
Concentration for intradermal injection: 0.25% *
Concentration for topical application: 25% *
*: highest to cause mild-to-moderate skin irritation based on preliminary assays

Challenge phase:
Concentration for topical application: 0.5%**
** highest non-irritant concentration based on preliminary assays

Route:

other: cutaneous, occlusive

Vehicle:

other: corn oil (intradermal injection and induction application) and propylene glycol (challenge application)

Concentration / amount:

Induction phase:
Concentration for intradermal injection: 0.25% *
Concentration for topical application: 25% *
*: highest to cause mild-to-moderate skin irritation based on preliminary assays

Challenge phase:
Concentration for topical application: 0.5%**
** highest non-irritant concentration based on preliminary assays

No. of animals per dose:

- preliminary test: 8 animals
- main test: 30 animals.

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2
- Exposure period: topical induction: 48h
- Site: interscapular region
- Frequency of applications: once intradermal, once topical

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 4 weeks between injection (induction) and challenge
- Exposure period: 24h
- Site: right flank (test item) and left flank (vehicle)
- Evaluation (hr after challenge): 24, 48 h after removal of dressing

Positive control substance(s):

not required

Remarks:

mercaptobenzothiazole tested in another study

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0.5%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0.5%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.5%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0.5%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.5%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.5%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: other: CLP Regulation

Conclusions:

The test item did not induce delayed contact hypersensitivity in guinea pigs.
Consequently, the test item should not be classified as a skin sensitizer according to the criteria of CLP Regulation.

Executive summary:

The objective of this study was to evaluate the potential of the test item to induce delayed contact hypersensitivity in guinea pigs.

 

Methods

Three preliminary tests were performed in order to determine the test item concentrations to be used in the main test.

 

In the main test, one treated group of ten males and ten females received the test item:

.            on day 1 by intradermal injections in the interscapular region at the concentration of 0.25%,

.            on day 8 by topical application to the clipped interscapular region at 25%,

.            on day 22 by topical application to the right posterior flank at 0.5%. The left posterior flank of the animals received the vehicle.

 

Another control group of five males and five females received the vehicles:

.            corn oil on days 1 and 8 in the interscapular region,

.            propylene glycol on day 22 to the left posterior flank. The right posterior flank received the test item at 0.5%.

 

On day 1, three pairs of intradermal injections were performed in the interscapular region of animals:

.            Freund's Complete Adjuvant (FCA) diluted to 50% (v/v) with 0.9% NaCl,

.            test item in vehicle or vehicle alone,

.            test item in a mixture FCA/corn oil (50/50, w/w) or vehicle at 50% (w/v) in FCA/corn oil (50/50, v/v).

 

As in the preliminary tests, the highest well-tolerated concentration was shown to be non-irritant after topical application, 0.5 mL of sodium lauryl sulfate at 10% (w/w) in vaseline was applied on the induction site on day 7 in order to induce a local irritation.

 

On day 8, a filter paper (approximately 8 cm²) was fully-loaded with the dose formulations, and then applied to the clipped interscapular region, over the intradermal injection sites. The filter paper was held in place by an occlusive dressing for 48 hours. The control group received an application of the vehicle under the same experimental conditions. The presence of local irritation was checked (but not scored).

The induction phase was followed by a 14-day rest period.

 

On day 22, a Finn Chamber filter paper was fully-loaded with the dosage forms. The chamber was held in contact with the skin by an occlusive dressing for 24 hours. The test item was applied on the right posterior flank. The vehicle was applied on the left posterior flank under the same experimental conditions. Cutaneous reactions were evaluated before treatment and 24 and 48 hours after removal of the dressing.

 

Each animal was observed once a day for mortality and clinical signs during the treatment and observation periods. Body weight was recorded on day 1 and at the end of each observation period.

On completion of the observation period, the animals were sacrificed and discarded without macroscopic post-mortem examination. No skin samples were preserved.

Results

No unscheduled deaths occurred during the main test.

No clinical signs indicative of systemic toxicity were observed in any animals.

Scabs and wounds were observed in all animals of groups 4 and 5 at the intradermal injection sites, associated with cracks in 2/10 males and 3/10 females of group 5.

 

Mean body weights were unaffected by the test item treatment.

There were no cutaneous reactions incontrol and test item-treated groups.

 

Conclusion

The test item did not induce delayed contact hypersensitivity in guinea pigs.

Consequently, the test item should not be classified as a skin sensitizer according to the criteria of CLP Regulation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The potential of the registered substance to induce delayed contact hypersensitivity was evaluated in guinea pigs according to the maximization method of Magnusson and Kligman and to OECD (No. 406, 17^thJuly 1992) guideline. The study was conducted in compliance with the principles of Good Laboratory Practice Regulations.

Thirty guinea pigs were allocated to two groups: a control group of five males and fives females and a treated group of ten males and ten females.

On day 1, three pairs of intradermal injections were performed in the interscapular region of animals:

.            Freund's Complete Adjuvant (FCA) diluted to 50% (v/v) with 0.9% NaCl,

.            test item in vehicle or vehicle alone,

.            test item in a mixture FCA/corn oil (50/50, w/w) or vehicle at 50% (w/v) in FCA/corn oil (50/50, v/v).

As in the preliminary tests, the highest well-tolerated concentration was shown to be non-irritant after topical application, 0.5 mL of sodium lauryl sulfate at 10% (w/w) in vaseline was applied on the induction site on day 7 in order to induce a local irritation.

 On day 8, a filter paper (approximately 8 cm²) was fully-loaded with the dose formulations, and then applied to the clipped interscapular region, over the intradermal injection sites. The filter paper was held in place by an occlusive dressing for 48 hours. The control group received an application of the vehicle under the same experimental conditions. The presence of local irritation was checked (but not scored).The induction phase was followed by a 14-day rest period.

On day 22, a Finn Chamber filter paper was fully-loaded with the dosage forms. The chamber was held in contact with the skin by an occlusive dressing for 24 hours. The test item was applied on the right posterior flank. The vehicle was applied on the left posterior flank under the same experimental conditions. Cutaneous reactions were evaluated before treatment and 24 and 48 hours after removal of the dressing.

Each animal was observed once a day for mortality and clinical signs during the treatment and observation periods. Body weight was recorded on day 1 and at the end of each observation period.

On completion of the observation period, the animals were sacrificed and discarded without macroscopicpost-mortemexamination. No skin samples were preserved.

 

No unscheduled deaths occurred during the main test.No clinical signs indicative of systemic toxicity were observed in any animals.Scabs and wounds were observed in all animals of groups 4 and 5 at the intradermal injection sites, associated with cracks in 2/10 males and 3/10 females of group 5.Mean body weights were unaffected by the test item treatment.There were no cutaneous reactions in control and test item-treated groups.Consequently, the test item should not be classified as a skin sensitizer according to the criteria of CLP Regulation.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

The registered substance is a solid with a melting point of 77°C and a vapour pressure around 0.0079 Pa at 20°C (value based on read-across from oleylamine). Also the use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalation route and thus risk of respiratory sensitisation will be unlikely to occur.

Justification for classification or non-classification

Skin sensitisation:

According to the criteria laid down in EU regulation (EC) n°1272/2008 (CLP), the substance has not to be classified for skin sensitisation.