Fatty acids, rape-oil, mixed esters with 1,4:3,6-dianhydro-d-glucitol, sorbitan and sorbitol

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:

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

Adequacy of study:

key study

Study period:

August 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study. According to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Groupe interministeriel des produits chimiques GIPC - DGCIS - SI BP 80001 - 67 rue Barbes - 94201 Ivry-sur-Seine, France

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The test was performed in 2012 when the OECD Guideline 429 was the current version addressing the skin sensitisation potential of chemicals in vivo. However, despite the advantages of the LLNA over TG 406, it should be recognised that there are certain limitations that may necessitate the use of guinea pig tests (i.e. TG 406) (e.g. false negative findings in the LLNA with certain skin irritants [such as some surfactant type chemicals] or solubility of the test substance).

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River (F-69592 L'Arbresle)
- Age at study initiation: 4 weeks
- Weight at study initiation: 230-290 g
- Housing: individually or 2 animals in polycarbonate containers
- Diet (ad libitum): SDS, FD1
- Water (ad libitum): tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal and epicutaneous

Vehicle:

other: olive oil (intradermal injections), liquid paraffin (topical applications)

Concentration / amount:

Intradermal induction: 2%
Epicutaneous induction: 100%
Challenge: 50 and 100%

Route:

epicutaneous, occlusive

Vehicle:

other: olive oil (intradermal injections), liquid paraffin (topical applications)

Concentration / amount:

Intradermal induction: 2%
Epicutaneous induction: 100%
Challenge: 50 and 100%

No. of animals per dose:

5 (negative control)
10 (test groups)

Details on study design:

RANGE FINDING TESTS:
Three preliminary studies were performed.
For determination of the maximal non necrotising concentration after intradermal injection of the test substance, two animals received a volume of 0.1 mL of the test item on both sides of the spine, at concentrations of 10, 20, 50 and 100% in olive oil, respectively. A macroscopic evaluation of the cutaneous reactions was conducted 24 hours after the injections. Due to necrosis observed at all concentrations, the same animals received a volume of 0.1 mL of the test item on both sides of the spine, at 3 concentrations: diluted at 1, 2 and 5% in olive oil, respectively. A macroscopic evaluation of the cutaneous reactions was conducted 24 hours after the injections. No necrosis was observed at the concentration of 2 %.
To determine the pre-maximal non-irritant concentration after topical application, the test item was applied on the dorso-lumbar zone of two guinea pigs shorn beforehand, with occlusive dressing for 24 hours, at 4 different concentrations: 40, 60, 80 and 100% in liquid paraffin. A macroscopic evaluation of the cutaneous reactions was conducted 24 hours after removal of the dressing. No macroscopic findings were noted on the treated areas up to 100% test substance concentration.
To determine the maximal non-irritant concentration after topical application, three guinea pigs were treated according to the same treatment as animals from the negative control for the intradermal and epicutaneous induction phase in the main test (i.e. olive oil and liquid paraffin). During the challenge phase, the animals were treated with the test item placed onto the selected treatment sites and covered with an occlusive dressing for a period of 24 hours at 4 different concentrations: 100, 80, 60 and 40% in liquid paraffin. A macroscopic evaluation of the cutaneous reactions was conducted 24 and 48 hours after removal of the occlusive dressing and rinsed with distilled water. As no macroscopic findings were observed on the treated areas, concentrations of 50 and 100% test substance concentration for chosen for the challenge phase.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous, respectively)
- Exposure period: single injection (intradermal) and 48 h (epicutaneous)
- Negative control group:
Intradermal (3 pairs of injections, each 0.1 mL):
Injection 1: 1:1 mixture (v/v) FCA/isotonic sodium chloride
Injection 2: olive oil
Injection 3: 1:1 mixture (v/v) FCA/olive oil
- Test group:
Intradermal (3 pairs of injections):
Injection 1: 1:1 mixture (v/v) FCA/isotonic sodium chloride
Injection 2: 2 % test substance in olive oil
Injection 3: FCA at 50% and the test item at 4 % in olive oil

Epicutaneous:
- Test group: 0.5 mL of the test item at 100%
- Negative control: 0.5 mL of liquid paraffin

- Site: scapular zone (intradermal + epicutaneous)
- Frequency of applications: single
- Duration: Days 0-8 (On day 6, one day prior to epicutaneous induction, the shorn skin of all animals in each group was brushed with a solution of sodium lauryl sulphate at 10% in thick vaseline, in order to create a local irritation).

B. CHALLENGE EXPOSURE
- No. of exposures: 1 (challenge)
- Day(s) of challenge: 20 (challenge)
- Exposure period: 24 h
- Test groups: 50 and 100 % test substance
- Control group: 50 and 100 % test substance
- Site: shorn dorso-lumbar zone, on either side of the spine
- Concentrations: 50 and 100 %
- Evaluation (hr after challenge): 48 and 72 h

C. RECHALLENGE EXPOSURE
- No. of exposures: 1 (rechallenge)
- Day(s) of challenge: 28 (rechallenge)
- Exposure period: 24 h
- Test groups: 25 and 50 % test substance
- Control group: 25 and 50 % test substance
- Site: shorn dorso-lumbar zone, on either side of the spine
- Concentrations: 25 and 50 %
- Evaluation (hr after challenge): 48 and 72 h

Challenge controls:

The control group is actually a challenge control.

Positive control substance(s):

yes

Remarks:

alpha-Hexylcinnamaldehyde (CAS No 101-86-0, routinely evaluated every 6 month at challenge concentrations of 6.25 and 12.5%, thus meeting the reliabilty criteria)

Positive control results:

Alpha-Hexylcinnamaldehyde (at 6.25 and 12.5% challenge concentrations) induced sensitisation in up to 100% of the treated animals.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50% (at challenge)

No. with + reactions:

5

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 50% (at challenge). No with. + reactions: 5.0. Total no. in groups: 5.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

2% (induction), 50% (at challenge)

No. with + reactions:

6

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 2% (induction), 50% (at challenge). No with. + reactions: 6.0. Total no. in groups: 10.0.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

100% (at challenge)

No. with + reactions:

5

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 100% (at challenge). No with. + reactions: 5.0. Total no. in groups: 5.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

2% (induction), 100% (at challenge)

No. with + reactions:

9

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 2% (induction), 100% (at challenge). No with. + reactions: 9.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

50% (at challenge)

No. with + reactions:

3

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 50% (at challenge). No with. + reactions: 3.0. Total no. in groups: 5.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

2% (induction), 50% (at challenge)

No. with + reactions:

4

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 2% (induction), 50% (at challenge). No with. + reactions: 4.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

100% (at challenge)

No. with + reactions:

4

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 100% (at challenge). No with. + reactions: 4.0. Total no. in groups: 5.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

2% (induction), 100% (at challenge)

No. with + reactions:

5

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 2% (induction), 100% (at challenge). No with. + reactions: 5.0. Total no. in groups: 10.0.

Reading:

rechallenge

Hours after challenge:

24

Group:

negative control

Dose level:

25% (at challenge)

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 24.0. Group: negative control. Dose level: 25% (at challenge). No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

2% (induction), 25% (at challenge)

No. with + reactions:

1

Total no. in group:

10

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 2% (induction), 25% (at challenge). No with. + reactions: 1.0. Total no. in groups: 10.0.

Reading:

rechallenge

Hours after challenge:

24

Group:

negative control

Dose level:

50% (at challenge)

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 24.0. Group: negative control. Dose level: 50% (at challenge). No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

2% (induction), 50% (at challenge)

No. with + reactions:

2

Total no. in group:

10

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 2% (induction), 50% (at challenge). No with. + reactions: 2.0. Total no. in groups: 10.0.

Reading:

rechallenge

Hours after challenge:

48

Group:

negative control

Dose level:

25% (at challenge)

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: 25% (at challenge). No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

2% (induction), 25% (at challenge)

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 2% (induction), 25% (at challenge). No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

rechallenge

Hours after challenge:

48

Group:

negative control

Dose level:

50% (at challenge)

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: 50% (at challenge). No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

2% (induction), 50% (at challenge)

No. with + reactions:

1

Total no. in group:

10

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 2% (induction), 50% (at challenge). No with. + reactions: 1.0. Total no. in groups: 10.0.

Group:

positive control

Remarks on result:

other: No information available

During the induction phase, no cutaneous reaction was observed. Dryness was recorded in one animal of the control group (1/5) and in nine animals of the treatment group (9/10), 24 hours after the epicutaneous induction.

No abnormality was recorded in the body weight gain of both groups. No mortality was registered during the main test.

In the treatment group (treatment dose of 100%), slight to moderate erythema was noted in 90% (9/10), in 50% (5/10) and in 10% (1/10) of the animals, 24, 48 and 72 hours, respectively, after the challenge phase, on the treated area. Slight oedema was noted in 20% (2/10) of the animals, only 24 hours after the challenge phase, on the treated area.

In the control group (associated with the treatment dose of 100%), slight to moderate erythema was noted in 100% (5/5,) in 80% (4/5) and in 60% (3/5) of the animals, 24, 48 and72 hours, respectively, after the challenge phase, on the area challenged with the test substance at 100%. Slight oedema was noted in 80% (4/5) of the animals, only 24 hours after the challenge phase, on the treated skin.

In the treatment group (treatment dose of 50%), slight to moderate erythema was noted in 60% (6/10), in 40% (4/10) and in 10% (1/10) of the animals, 24, 48 and 72 hours, respectively, after the challenge phase, on the treated area. Slight oedema was noted in 10% (1/10) of the animals, only 24 hours after the challenge phase, on the treated area.

In the control group (associated with the treatment dose of 50%), slight to moderate erythema was noted in 100% (5/5), in 60% (3/5) and in 20% (1/5) of the animals, 24, 48 and 72 hours, respectively, after the challenge phase, on the area cheallenged with the test item at 50%. Slight oedema was noted in 20% (2/5) of the animals, only 24 hours after the challenge phase, on the treated area.

As irritation was observed in the control group animals, only reactions in the test group animals that exceeded the most severe reactions seen in the control group animals were attributed to skin sensitisation. Therefore, no sensitisation reaction was noted in animals from the treated group with the test item at 100 and 50%. To clarify these results, a rechallenge phase was performed with the test item diluted at 50 and 25% after a rest phase of 6 days.

In the treatment group (treatment dose of 50%), slight erythema was noted in 20% (2/10) and in 10% (1/10) of the animals from the treated group, 24 and 48 hours after the rechallenge phase, on the treated area. No skin reaction was noted at the reading time 72 hours. No cutaneous intolerance reaction was recorded in animals from the negative control group after the rechallenge phase, on the treated area, with the test item at 50%.

In the treatment group (treatment dose of 25%), slight erythema was noted in 10% (1/10) of the animals from the treated group, only 24 hours after the rechallenge phase, on the treated area. No skin reaction was noted at the reading time 72 hours. No cutaneous intolerance reaction was recorded in animals from the negative control group after the rechallenge phase, on the treated area, with the test item at 25%.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Sensitisation

Justification for read-across

There are no data on sensitisation available for Fatty acids, rape-oil, mixed esters with 1,4:3,6-dianhydro-d-glucitol, sorbitan and sorbitol. In accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5 read-across from appropriate substances is conducted to fulfill the standard information requirements set out in Regulation (EC) No 1907/2006, Annex VIII, 8.5.

According to Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met”. In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across) “to avoid the need to test every substance for every endpoint”. 

 

Fatty acids, rape-oil, mixed esters with 1,4:3,6-dianhydro-d-glucitol, sorbitan and sorbitol represents an UVCB substance comprised of different Sorbitan fatty acid ester, mainly of mono-, di- and tri-esters of sorbitol, sorbitan and 1,4:3,6-dianhydro-d-glucitol esterified with natural fatty acids with a chain length ranging from of C16 – C20, mostly C18 mono-unsaturated.

 

Sorbitan fatty acid esters are known to be stepwise hydrolysed to the respective fatty acid and the alcohol moiety, which will be present mostly as the open chain isomer D-glucitol depending on the pH (Stryer, 1996). The first cleavage product, the fatty acid, is stepwise degraded by beta-oxidation based on enzymatic removal of C2 units in the matrix of the mitochondria in most vertebrate tissues. For the complete catabolism of unsaturated fatty acids such as oleic acid, an additional isomerization reaction step is required. The alpha- and omega-oxidation, alternative pathways for oxidation, can be found in the liver and the brain, respectively (CIR, 1987). The alcohol residue, mostly D-glucitol, is absorbed from the gastro-intestinal tract and can be metabolized by the intestinal microflora (Senti, 1986) or in the liver (Touster, 1975). Based on the common metabolic fate of Sorbitan fatty acid esters, the read-across approach is based on the presence of common functional groups, common precursors and the likelihood of common breakdown products via biological processes, which result in structurally similar chemicals and hence exhibit similar toxicokinetic behaviour. For further details on the read-across approach, please refer to the analogue justification in section 13 of the technical dossier.

 

As no data are available on sensitizing properties of Fatty acids, rape-oil, mixed esters with 1,4:3,6-dianhydro-d-glucitol, sorbitan and sorbitol , read-across to reliable data on the analogue substance Anhydro-D-glucitol trioleate (CAS 26266-58-0) was conducted.

 

CAS 26266-58-0

A guinea pig maximisation test was performed with Anhydro-D-glucitol trioleate (Sorbitan trioleate) according to OECD guideline 406 under GLP conditions (Phycher Bio Developpment 2012). The test substance was applied in olive oil for intradermal induction at a concentration of 2%, at 100% for epidermal induction and at 50 and 100% for challenge and rechallenge, respectively. At challenge, irritation was observed in almost all animals of the negative control group. Therefore, only reactions in the test group that exceeded the most severe reactions seen in the control group were attributed to skin sensitisation. Hence, no sensitisation reaction was noted in animals from the treated group with the test item at 50 and 100%. In view to clarify these results, a rechallenge phase was performed with the test item diluted at 25 and 50%. No effects were then observed in the negative control group. In the test group challenged with 25 and 50% test substance, 10 and 20% of the animals, respectively, showed a positive reaction 24 h after rechallenge. After 48 h, 10% of the animals treated with 50% test substance during the rechallenge phase showed a positive reaction. The positive control (6.25 and 12.5% alpha-hexylcinnamaldehyde) induced the expected result. Based on these results, Anhydro-D-glucitol trioleate (Sorbitan trioleate) was considered not to be sensitising.

 

 

Human data

In addition to the available data on Anhydro-D-glucitol trioleate (Sorbitan trioleate) on sensitization in guinea pigs, human data are available for the read-across substances Anhydro-D-glucitol trioleate (Sorbitan trioleate), Sorbitan, (Z)-9-octadecenoate (2:3) and for Sorbitan laurate. Due to limited documentation, the data are considered as not assignable and are therefore not taken into account for hazard assessment.

 

CAS 26266-58-0

2 human patch tests are available for Anhydro-D-glucitol trioleate: The undiluted test substance was initially applied to the skin of 50 volunteers for 3 days. 7 days after removal of the test substance, challenge occurred for additional 3 days. 50 volunteers were included as respective negative control group. No sensitising effects were observed (Schwartz 1959). Furthermore, Anhydro-D-glucitol trioleate failed to induce sensitizing reactions to the skin in 10 volunteers treated with 30% test substance applied to 10 volunteers in an epicutaneous patch test (Durfee 1946).

 

CAS 8007-43-0

For Sorbitan, (Z)-9-octadecenoate (2:3) human data on sensitisation is available. A human patch test was performed with 50 volunteers under occlusive conditions. The undiluted test substance was initially applied for 3 days and a challenging application for 3 days was done 7 days after removal of the initial patch. None of the volunteers showed a sensitisation reaction to Sorbitan, (Z)-9-octadecenoate (2:3) (Schwartz 1959).

 

In 2002, Uniqema performed a study, investigating a 30% aqueous dispersion in 10 volunteers under occlusive conditions for an initial application of 5 days and a challenge of 2 days after a 10-day induction period. No reaction occurred among the 10 participants following either the first or second application of the test substance. This indicates that the substance is not a skin sensitiser (Uniqema 2002). Hence, based on human data, Sorbitan, (Z)-9-octadecenoate (2:3) does not exhibit skin sensitizing properties.

 

CAS 1338-39-2 

For the analogue substance Anhydro-D-glucitol trioleate, two human patch tests are available performed with a test substance concentration of 50%. In detail, 50 volunteers were initially treated for 3 days and challenged for 3 days, 7 days after removal of the initial patch. No sensitising effects were observed (Schwartz 1959). Likewise, a patch test with 30% test substance applied to 10 volunteers induced no sensitising potential (Durfee 1946).

 

CAS 1338-43-8

Further, a human patch test is available for Sorbitan laurate in which 50 volunteers were treated with the test substance under occlusive conditions for 72 h (Schwartz, 1959). One week later, patches were re-applied for 72 hours; followed by scoring of the sensitising effects. No sensitising effects were noted in the volunteers.

Overall conclusion for skin sensitisation

Based on reliable animal data, the structural analogue substance Anhydro-D-glucitol trioleate is not considered as skin sensitising. Hence, Fatty acids, rape-oil, mixed esters with 1,4:3,6-dianhydro-d-glucitol, sorbitan and sorbitol are not expected to exhibit skin sensitizing properties.

 

References

CIR (1987). Final report on the safety assessment of oleic acid, lauric acid, palmitic acid, myristic acid, stearic acid. J. of the Am. Coll. of Toxicol.6 (3): 321-401

 

Senti, F.R. 1986. Health aspects of sugar alcohols and lactose. Contract No. 223-83-2020, Center for food safety and applied nutrition, Food and Drug Administration, Dept. of Health and Human Services, Washington, DC 20204, USA

 

Stryer, L. 1996. Biochemie. Spektrum Akademischer Verlag; Auflage: 4th edition

Suldano, S., Gramenzi, F., Cirianni, M., Vittozzi, L. (1992): Xenobiotic-metabolizing enzyme systems in test fish - IV. Comparative studies of liver microsomal and cytosolic hydrolases. Comparative Biochemistry and Physiology Part C: Comparative Pharmacology. 101(1), 117-123.

 

Touster, O. 1975: Metabolism and physiological effects of polyols (alditols). In : Physiological effects of food carbohydrates.Washington, DC: American Chemical Society. p 229-239

 

Migrated from Short description of key information:
skin sensitisation (OECD 406): no skin sensitising effects

Justification for selection of skin sensitisation endpoint:
Hazard assessment is conducted by means of read-across from a structural analogue/surrogate. The selected study is the most adequate and reliable study based on the identified similarities in structure and intrinsic properties between source and target substance and overall quality assessment (refer to the endpoint discussion for further details).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on skin sensitisation of the structural analogue do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.

No data on respiratory sensitisation are available.