3-sec-[C15-18-(branched and linear)-alk-2-enyl]pyrrolidine-2,5-dione

Endpoint summary

Description of key information

No evidence of skin sensitisation was observed in a Buehler Test conducted in guinea pigs according to OECD Test Guideline 406.

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:

6th November - 12th November 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

A Buehler study was conducted for research and development purposes. However, in the interest of promotong the 3R principle it would be unethical to run another in vivo study to the LLNA method.

Species:

guinea pig

Strain:

Hartley

Sex:

male

Details on test animals and environmental conditions:

Prior to use, all animals were acclimated for at least five days. Animals were individually housed
in wire mesh suspension cages. The animals were maintained on a 12-hour cycle light controlled
room, at a temperature of 64° - 79°F and a relative humidity of 30-70%.

Route:

epicutaneous, semiocclusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

0.4 mL at a 20% concentration

Day(s)/duration:

six hours

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Route:

epicutaneous, semiocclusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

5%

Day(s)/duration:

14

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

20 animals in test group,
6 control animals

Details on study design:

0.4 ml of the test substance at a 20% concentration diluted in mineral oil directly into Hilltop Chambers® and applying
them to the clipped left shoulder of twenty albino guinea pigs in the following manner: The
animals were held gently, and the chambers were applied as quickly as possible to the clipped left
shoulder. The chambers were secured with Micropore tape and further secured with Kendall
adhesive tape. Approximately six hours later, the tape and chambers were removed. Two
additional induction doses were conducted following the same procedure, at weekly intervals.
Two weeks after the final application the animals received a topical primary challenge dose (6
hour contact) of X-16151, Batch #: R17-2934 at 5% concentration diluted in mineral oil, on a naive
site located on the right shoulder. Animals were scored for irritation at 24 and 48 hours after
initiation of the primary challenge application.
Ten guinea pigs served as a naive control group, and remained untreated through the induction
phase. Six naive control animals received only the primary challenge dose, at a 5% concentration
diluted in mineral oil. The four remaining guinea pigs were designated for a re-challenge, if
necessary.

Positive control substance(s):

no

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

no indication of skin sensitisation

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

no indication of skin sensitisation

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

5%

No. with + reactions:

0

Total no. in group:

6

Remarks on result:

no indication of skin sensitisation

Group:

positive control

Remarks on result:

not measured/tested

Interpretation of results:

GHS criteria not met

Conclusions:

The test susbtance did not induce skin sensitization

Executive summary:

The test substance was evaluated for sensitization potential by applying 0.4 ml at a 20% concentration diluted in mineral oil directly into Hilltop Chambers® and applying them to the clipped left shoulder of twenty albino guinea pigs in the following manner: The animals were held gently, and the chambers were applied as quickly as possible to the clipped left

shoulder. The chambers were secured with Micropore tape and further secured with Kendall adhesive tape. Approximately six hours later, the tape and chambers were removed. Two additional induction doses were conducted following the same procedure, at weekly intervals.

Two weeks after the final application the animals received a topical primary challenge dose (6 hour contact) of the test substance at 5% concentration diluted in mineral oil, on a naive site located on the right shoulder. Animals were scored for irritation at 24 and 48 hours after initiation of the primary challenge application.

Ten guinea pigs served as a naive control group, and remained untreated through the induction phase. Six naive control animals received only the primary challenge dose, at a 5% concentration diluted in mineral oil. The four remaining guinea pigs were designated for a re-challenge, if necessary.

Following primary challenge of test substance at 5% concentration, the incidence of grade 1 response or greater in the test group (0 of 20) was compared to that of the naive control group (0 of 6). The incidence and severity of these responses were not significantly greater than those produced by the naive control group indicating that sensitization had not been induced.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The test substance was evaluated for sensitization potential by applying 0.4 ml at a 20% concentration diluted in mineral oil directly into Hilltop Chambers® and applying them to the clipped left shoulder of twenty albino guinea pigs in the following manner: The animals were held gently, and the chambers were applied as quickly as possible to the clipped left

shoulder. The chambers were secured with Micropore tape and further secured with Kendall adhesive tape. Approximately six hours later, the tape and chambers were removed. Two additional induction doses were conducted following the same procedure, at weekly intervals.

Two weeks after the final application the animals received a topical primary challenge dose (6 hour contact) of the test substance at 5% concentration diluted in mineral oil, on a naive site located on the right shoulder. Animals were scored for irritation at 24 and 48 hours after initiation of the primary challenge application.

Ten guinea pigs served as a naive control group, and remained untreated through the induction phase. Six naive control animals received only the primary challenge dose, at a 5% concentration diluted in mineral oil. The four remaining guinea pigs were designated for a re-challenge, if necessary.

Following primary challenge of test substance at 5% concentration, the incidence of grade 1 response or greater in the test group (0 of 20) was compared to that of the naive control group (0 of 6). The incidence and severity of these responses were not significantly greater than those produced by the naive control group indicating that sensitization had not been induced.

The study was assessed as Klimisch 1, as it is compliant with GLP and OECD Test Guidelines. It is therefore considered to be sufficiently reliable for classification purposes. In vitro skin sensitisation studies are not available; these do not need to be conducted since adequate data are already available from an in vivo skin sensitisation study.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

No data are available on respiratory sensitisation. However, exposure of humans via inhalation is considered unlikely.

Justification for classification or non-classification

Based on the available data, the substance is not classified for skin sensitisation in accordance with Regulation (EC) No. 1272/2008. No data are available on respiratory sensitisation.