Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol

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:

16 Apr - 18 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-guideline study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Bayerisches Landesamt für Gesundheit und Lebensmitelsicherheit, Landesinstitut für Arbeitsschutz und Produktsicherheit, München, Germany

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

There were hints that the substance is not a strong sensitiser, and the GPMT is the better method to detect weak sensitisers

Species:

guinea pig

Strain:

other: Crl:HA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River, Sulzfeld, Germany
- Age at study initiation: 4 weeks
- Weight at study initiation: 369-467 g
- Housing: The animals were kept in groups.
- Diet: Altromin 3122 maintenance diet for guinea pigs (preliminary test: lot no. 061211; main study: lot no. 261111), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 55± 10
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal and epicutaneous

Vehicle:

cotton seed oil

Concentration / amount:

Induction: 5% (intradermal), 100% (topical)
Challenge: 100%

Route:

epicutaneous, occlusive

Vehicle:

cotton seed oil

Concentration / amount:

Induction: 5% (intradermal), 100% (topical)
Challenge: 100%

No. of animals per dose:

Negative control group: 5 animals
Test group: 10 animals

Details on study design:

RANGE FINDING TESTS:
Three animals were used in the range-finding tests. Animal 1 was treated intradermally with concentrations of 1%, 1.5%, 2.5%, and 5% of the test item dissolved in cotton seed oil. Animal 2 was treated topically with 50% and 100% of the test item dissolved in vaseline for 24 h. Animal 3 was treated equivalent to animal 2 for 48 h. Based on the results a concentration of 5% was chosen for the intradermal application of the main test. This concentration caused slight signs of irritation, without leading to systemic effects. A concentration of 100% was found to be the highest concentration that did not cause any signs of irritation after topical treatment.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous)
- Exposure period: single injection (intradermal) and 48 h (epicutaneous)
- Test groups:
Intradermal (3 pairs of injections):
Injection 1: a 1:1 mixture (v/v) FCA/physiological saline 0.9% NaCl
Injection 2: test substance (5%) in cotton seed oil
Injection 3: test substance (5%) in a 1:1 mixture (v/v) FCA/physiological saline 0.9% NaCl
Epicutaneous: 100% test substance (0.5 g)
- Control group:
Intradermal (3 pairs of injections):
Injection 1: a 1:1 mixture (v/v) FCA/physiological saline 0.9% NaCl
Injection 2: 100% cotton seed oil
Injection 3: a 50% (v/v) formulation of cotton seed oil in a 1:1 mixture (v/v) FCA/physiological saline 0.9% NaCl
Epicutaneous: 100% vaseline
- Site: shoulder region
- Frequency of applications: every 7 days
- Duration: day 0-7
- Concentrations: intradermal 5%, epicutaneous 100%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day of challenge: 20
- Exposure period: 24 h
- Test groups: 0.5 g of test item (100%)
- Control group: 0.5 g of test item (100%)
- Site: left flank (test item), right flank (vehicle)
- Concentrations: 100%
- Evaluation (hr after challenge): 24 and 48 h

Challenge controls:

The control group is actually a challenge control.

Positive control substance(s):

yes

Remarks:

reliability check with mercaptobenzothiazole

Positive control results:

The positive control substance (induction 1: 15%; induction 2: 25%; challenge: 15% mercaptobenzothiazole) induced positive reactions in 10/10 animals (100%), thus meeting the reliability criteria for the GPMT.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

5%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 5%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

5%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 5%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

5%

No. with + reactions:

2

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 5%. No with. + reactions: 2.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5%

No. with + reactions:

2

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 5%. No with. + reactions: 2.0. Total no. in groups: 10.0.

Summary of sensitisation after challenge in comparison to control animals

	Erythema reaction (grade 0-3)				Oedema reaction (grade 0-3)
	E0	E1	E2	E3	O0	O1	O2	O3	Sensitised animals (%)
Treated animals after 24 h	8	2	-	-	10	-	-	-	20
Treated animals after 48 h	8	2	-	-	10	-	-	-	20
Controls after 24 h	5	-	-	-	5	-	-	-	0
Controls after 48 h	5	-	-	-	5	-	-	-	0

 

Absolute body weights in g (Test group)

Test group
Date	Animal No.
	T1	T2	T3	T4	T5	T6	T7	T8	T9	T10
2012-04-24	377	396	383	402	383	441	414	452	415	455
2012-05-18	488	506	522	490	500	573	528	626	543	585
Weight gain	111	110	139	88	117	132	114	164	128	130

 

Absolute body weights in g (Control group)

Control group
Date	Animal No.
	T1	T2	T3	T4	T5
2012-04-24	467	464	435	417	369
2012-05-18	618	612	605	564	470
Weight gain	151	148	170	147	101

 

Grading of reactions in the preliminary test (intradermal)

Animal No.	Conc. (%)	E (24 h)	O (24 h)	E (48 h)	O 48 (h)	E (72 h)	O (72 h)
1	5	E1	O1	E1	O1	E1	O1
	2.5	E1	O1	E1	O1	E1	nsf
1	1.5	E1	nsf	E1	nsf	E1	nsf
	1	E1	nsf	E1	nsf	E1	nsf

E: erythema (grade 0 -3); O: Oedema (grade 0 -3); nsf: no specific findings

Grading of reactions in the preliminary test (epicutaneous)

Animal No.	Conc. (%)	E (24 h)	O (24 h)	E (48 h)	O 48 (h)	E (72 h)	O (72 h)
2 (24-h exposure)	100	nsf	nsf	nsf	nsf	nsf	nsf
	50	nsf	nsf	nsf	nsf	nsf	nsf
1(48-h exposure)	100	nsf	nsf	nsf	nsf	nsf	nsf
	50	nsf	nsf	nsf	nsf	nsf	nsf

E: erythema (grade 0 -3); O: Oedema (grade 0 -3); nsf: no specific findings

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A guinea pig maximisation test performed according to OECD 406 and in compliance with GLP, is available for assessment of the skin sensitising properties ofFatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol (Stelter 2012, 2012). 10 animals of the test group were induced with 5% (intradermally) and 100% (topically) test substance. The challenge application was performed at day 20 with 100% test substance. In addition 5 control animals were induced with cotton seed oil (intradermally) and vaseline (topically). The challenge application was performed at day 20 with 100% test substance. In the control group, no reactions were observed 24 and 48 h after the challenge application (0/5). In the test group, 2/10 animals showed a reaction at 24 and 48 h (erythema grade 1). For a positive result the criterion of = 30% positive reactions must be fulfilled. As only 20% positive reactions were observed (2/10), the test substance is considered to be not skin sensitising.

Migrated from Short description of key information:
Skin sensitisation (OECD 406): not sensitising

Justification for selection of skin sensitisation endpoint:
There is only one study available.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on substance specific study, the available data on the skin sensitisation potential do not meet the classification criteria according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.

There are no data available on respiratory sensitisation.