1,4-bis(2,3-epoxypropoxy)butane

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:

1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Well documented, according to accepted guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

reliability scoring based on 2001 guideline

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study was performed before LLNA test protocol was available

Species:

guinea pig

Strain:

other: Ibm: GOHI SPF

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: BRL, Biological Research Laboratories Ltd.
- Age at study initiation: 7 to 8 weeks
- Weight at study initiation: 314 to 346 g
- Housing: individually in Makrolon type-3 cages
- Diet (e.g. ad libitum): pelleted standard ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: one week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ±3
- Humidity (%): 40 to 70
- Air changes (per hr): 10 to 15/hr
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal and epicutaneous

Vehicle:

other: bi-distilled water

Concentration / amount:

1) Induction:
Intradermal injection: 1% (with bi-distilled water) of 0.1 mL
Epidermal application: 10% (in bi-distilled water) on a saturated 2 x 4 cm patch of filter paper
2) Challenge: 5% in bi-distilled water

Route:

epicutaneous, occlusive

Vehicle:

other: bi-distilled water

Concentration / amount:

1) Induction:
Intradermal injection: 1% (with bi-distilled water) of 0.1 mL
Epidermal application: 10% (in bi-distilled water) on a saturated 2 x 4 cm patch of filter paper
2) Challenge: 5% in bi-distilled water

No. of animals per dose:

Range finding tests: 1 male and 1 female for the intracutaneous test and 6 males and 5 females for the epicutaneous tests.
Main study: 5 animals/sex for control group and 10 animals/sex for the test group

Details on study design:

RANGE FINDING TESTS: The objective of preliminary study was to identify irritation test article concentrations suitable for the induction phase of the main study. In addition, a suitable non-irritant concentration of the test article, by the topical route of administration, was identified for the challenge application.
1) Intradermal injections: Intradermal injections (0.1 mL/site) were made into the clipped flank of two guinea-pigs at concentrations of 5, 3, and 1% of the test article in bi-distilled water. The resulting dermal reactions were assessed 24 hours later.
2) Epidermal application: Patches of filter paper (2 x 2 cm) were saturated with concentrations of 25, 15, 10, and 5% of the test article in bi-distilled water and applied to the clipped and shaved flanks of each of four guinea-pigs. The patches were covered by a strip of aluminum foil and firmly secured by elastic plaster wrapped around the trunk and covered with impervious adhesive tape. The dressings were removed after an exposure period of 24 hours and the reaction sites were assessed for erythema and edema on a numerical basis according to the scale 24 and 48 hours after removal of the dressings. Two previous epidermal pre-tests were performed as described above, one with the undiluted test article and 75, 50, and 25% test article in vaseline, the second with the same concentrations in bi-distilled water. This latter was performed because the test article was not miscible in vasilne. The third epidermal pre-test described above was performed to confirm the previous results and to determine the slightly irritating and highest non-irritating concentration.

MAIN STUDY
A. INDUCTION EXPOSURE
I) Intradermal Injections:
An area of dorsal skin from the scapular region was clipped free of hair. Three pairs of intradermal injections (0.1mL/site) were made at the border of a 4 x 6 cm area in the clipped region as follows:
-Test group:
1) Freund's complete adjuvant 50:50 with bi-distilled water;
2) The test article, diluted to 1% with bi-distilled water; and
3) The test article diluted to 1% with bi-distilled water, emulsified in a 50:50 mixture of Freund's complete adjuvant and bi-distilled water.
-Control group:
1) Freund's complete adjuvant 50:50 with bi-distilled water;
2) Bi-distilled water; and
3) Freund's complete adjuvant 50:50 with bi-distilled water.
II) Epidermal Applications:
-Test group:
One week after the injections, the scapular area was again clipped and shaved free of hair. A 2 x 4 cm patch of filter paper was saturated with the test article (10% in bi-distilled water) and placed over the injection sites of the test animals. The patch was covered by aluminum foil and firmly secured by an elastic plaster wrapped around the trunk of the animal and secured with impervious adhesive tape. The dressings were left in place for approximately 48 hours. Reaction sites were assessed for erythema and edema 24 and 48 hours after removal of the dressing, using the numerical grading system.
-Control group:
The guinea-pigs of the control group were treated as described above with the omission of test article.

B. CHALLENGE EXPOSURE
The test and control guinea-pigs were challenged 2 weeks after the epidermal induction application. Hair was clipped and shaved from a 5 x 5 cm area on the left and right flank of each guinea-pig.
-Test group:
Two patches of filter paper were saturated with:
a) non-irritant concentration (5% in bi-distilled water) of the test article and
b) with the vehicle only
and applied to the left flank and right flank using the same method as for the epidermal application.
The dressings were removed approximately 24 hours later. The sites were assessed for erythema and edema 24 and 48 hours after removal of the dressing, using the numerical scoring system as described under preliminary study. Erythema and edema reactions were described. The challenge site was evaluated 24 and 48 hours after removal of the patch. The readings were made under artificial fluorescent light (daylight spectrum). The reactions were scored on the basis of the Draize score. Based upon the percentage of animals sensitised (24-hour reading), the test article was assigned to one of the following 5 grades of allergenic potency, ranging from weak to extreme.
Sensitisation rate (%): Grade: Classification
0 - 8: 1: Weak
9 - 28: 2: Mild
29 - 64: 3: Moderate
65 - 80: 4: Strong
81 - 100: 5: Extreme
-Control group:
The control animals were treated in the same way as described above.

OTHER: Erythema and edema were assessed using the following numerical grading system according to Draize:

Erythema and eschar formation:
No erythema:0
Very slight erythema (barely perceptible): 1
Well-defined erythema: 2
Moderate to severe erythema: 3
Severe erythema (beet redness) to slight eschar formation (injuries in depth): 4

Edema formation:
No edema: 0
Very slight edema (barely perceptible): 1
Slight edema (edges of area well-defined by definite raising): 2
Moderate edema (raised approximately 1 mm): 3
Severe edema (raised more than 1 mm and extending beyond the area of exposure): 4

Challenge controls:

See details on study design.

Positive control substance(s):

yes

Remarks:

formaldehyde

Positive control results:

For the induction period, a 20% dilution of formaldehydesung (HCHO) in bi-distilled water and for the challenge procedure, a 15% dilution of HCHO was used. Clear positive results were observed in the HCHO-treated animals after the epidermal challenge application (7 positive reactions among 10 animals tested). According to the results observed, it is considered that HCHO possess an strong skin sensitising (contact allergenic) potential in the guinea pig strain used (Ibm: GOHI; SPF-quality).

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

5%

No. with + reactions:

2

Total no. in group:

10

Clinical observations:

none

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 5%. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: none.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

5%

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

none

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 5%. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: none.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

5%

No. with + reactions:

17

Total no. in group:

20

Clinical observations:

none

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 5%. No with. + reactions: 17.0. Total no. in groups: 20.0. Clinical observations: none.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5%

No. with + reactions:

15

Total no. in group:

20

Clinical observations:

none

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 5% . No with. + reactions: 15.0. Total no. in groups: 20.0. Clinical observations: none.

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

15%

No. with + reactions:

7

Total no. in group:

10

Clinical observations:

not reported

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 15%. No with. + reactions: 7.0. Total no. in groups: 10.0. Clinical observations: not reported.

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

15%

No. with + reactions:

3

Total no. in group:

10

Clinical observations:

not reported

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 15%. No with. + reactions: 3.0. Total no. in groups: 10.0. Clinical observations: not reported.

Sensitizing Effects

CONTROL GROUP:

Two out of 10 and 1 out of 10 animals showed spontaneous positive erythema reactions after the first challenge when treated with the 5% test article dilution at the 24- and 49-hour reading, respectively. No positive erythema reactions were observed with bi-distilled water alone.

 

TEST GROUP:

Seventeen out of 20 and 15 out of 20 animals showed positive erythema reactions after the first challenge when treated with the 5% test article dilution at the 24- and 48-hour reading, respectively. No positive erythema reactions were observed with bi-distilled water alone.

 

MORTALITY/VIABILITY

No death occurred during the study.

 

SYMPTOMS, LOCAL

CONTROL GROUP:

Application area around the injection sites 1and 3 was found to show erythema and edema from day 2 to 7; necrosis were observed from day 8 to 21 and encrustations from day 20 to 31. No local symptoms were observed in injection site 2.

 

TEST GROUP:

Application area around the injections sites 1, 2 and 3 was found to show the same local symptoms as described above for the injections sites1 and 3 of control group.

 

On day 9 of test no observation could be performed because the animals were bandaged semi-occlusively.

 

SYMPTOMS, SYSTEMIC

No systemic symptoms were observed in the animals.

 

BODY WEIGHTS

The body weight gain of the animals was not affected adversely during the study.

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

From the results of this OECD 406 study a "strong" allergenic potency of the test article 1,4-butanediol digylcidyl ether (BDDGE) was concluded. The results were interpreted according to the rating of Magnusson and Kligman (1969). However, the test article was not classified as an "extreme" sensitizer, because 20% of the control animals showed positive erythema reactions at the 24-hour reading.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Skin sensitisation studies on butanediol diglycidyl ether in guinea pigs have demonstrated that the compound has skin sensitisation potential.

The skin sensitisation potential of butanediol diglycidyl ether was assessed in a study performed according to OECD Guidelines for the Testing of Chemicals No. 406 and in compliance with GLP in male and female Ibm: GOHI SPF guinea pigs (Ullmann et al., 1991). In the main study, 20 animals (10/sex) comprised the butanediol diglycidyl ether test group and 10 animals (5/sex) comprised the vehicle (bi-distilled water) control group. The intradermal induction was carried out with 0.1 mL of 1% butanediol diglycidyl ether in vehicle, and epicutaneous induction was performed with 10% butanediol diglycidyl ether in vehicle to the dorsal area (scapular region) under occlusive conditions. The epicutaneous challenge exposure was conducted with 5% butanediol diglycidyl ether in vehicle for a 24-hour exposure period. Skin reactions were observed and recorded 24 and 48 hours after removal of the dressing. Erythema and edema were assessed using the numerical grading system according to Draize. Based upon the percentage of animals sensitised (24-hour reading), the test article was assigned to one of the 5 grades of allergenic potency, ranging from weak to extreme. In the test group, 17 of 20 animals (85%) and 15 of 20 animals displayed positive erythema reactions at 24 and 48 hours, respectively, following challenge application with 5% butanediol diglycidyl ether in vehicle. Among 10 control animals, spontaneous positive erythema reactions were observed in 2 animals (20%) and 1 animal at 24 hours and 48 hours, respectively, following the challenge application with 5% butanediol diglycidyl ether in vehicle. In the control group, erythema and edema were observed around injection sites 1 and 3 from Days 2 to 7, necrosis was observed from Days 8 to 21, and encrustations from Days 20 to 31. No local symptoms were observed at injection site 2. Similarly, in the test group, the application area around injections sites 1, 2, and 3 was found to show the same local symptoms as described above for injections sites 1 and 3 of the control group. No death occurred during the study and body weight gains was not adversely affected during the study. No systemic symptoms were observed in all animals. Under the conditions of this study, the authors concluded that butanediol diglycidyl ether was considered to possess “strong allergenic potency” in guinea pigs. However, the authors commented that butanediol diglycidyl ether was not classified as an “extreme” sensitizer, as 20% of the control animals showed positive erythema reactions at the 24-hour reading.

The skin sensitisation potency of butanediol diglycidyl ether is supported by another skin sensitisation study performed according to OECD Guidelines for Testing of Chemicals No. 406 and in compliance with GLP (Ullmann and Kups, 1988). In this study, Dunkin Hartley guinea pigs (10/sex) were intradermally induced with 0.1 mL of 1% of butanediol diglycidyl ether in vehicle (distilled water), epicutaneously induced with 5% butanediol diglycidyl ether in vehicle, and epicutaneously challenged with 3% butanediol diglycidyl ether in vehicle. In the test group, 2 out of 20 and 1 out of 20 animals displayed positive reactions at the 24- and 48 -hour time points, respectively. Upon re-challenge (2 weeks after the first challenge), 5 out of 20 and 3 out of 20 animals displayed positive reactions at 24 and 24 hours, respectively. Therefore, butanediol diglycidyl ether was considered to possess “mild” allergenic potency in guinea pigs.

Similarly, butanediol diglycidyl ether was considered to possess skin sensitising (contact allergenic) potential in Pirbright white albino guinea pigs in skin sensitisation test (Maurer optimisation test) in which no guideline was followed. The method followed, however, was similar to that of the OECD Guidelines for Testing of Chemicals No. 406 (Kobel, 1981). In this study, guinea pigs (10/sex) were intradermally induced with 0.1% in 0.9% saline, intradermally challenged with 0.1% in 0.9% saline, and epicutaneously challenged with 0.5% butanediol diglycidyl ether in vaseline under occlusive conditions. A total of 17 out of 20 animals displayed positive reactions 24 hours after the intradermal challenge. All animals displayed positive reactions 24 hours after the epicutaneous challenge.

In contrast, butanediol diglycidyl ether was reported to possess no skin-sensitising (contact allergenic) potential in albino guinea pigs in another Maurer optimisation test by Sachsse and Ullmann (1976). This study followed no guidelines, however, the method followed (Maurer optimisation test) was similar to that of the 1981 OECD Guidelines for Testing of Chemicals No. 406. In this study, male and female Pirbright white guinea pigs (10/sex) were intradermally induced and intradermally challenged with 0.1% butanediol diglycidyl ether in saline. One male animal died spontaneously after the 10th sensitising injection in the test group. Three animals exhibited a positive reaction in the test group; however, the results were reported to be non-significant when compared to the vehicle control group in which no positive reactions were observed (results for the vehicle control group were not provided).

 

In conclusion, skin sensitisation studies on butanediol diglycidyl ether in guinea pigs, two of which were performed according to test guidelines, have demonstrated evidence of skin sensitisation potential. 

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Respiratory Sensitisation: There is no information available concerning respiratory sensitisation.

 

Skin Sensitisation: According to the Guidance on the Application of the CLP Criteria (ECHA Reference ECHA-09-G-02-EN), the in vivo test in rabbits according to OECD TG 406 is the standard test for the hazard assessment under the REACH. There are two GLP in vivo tests in rabbits according to OECD TG 406 which indicate that the notifiable substance is skin sensitising. As a result, the substance meets the criteria for category 1 classification according to Regulation (EC) No 1272/2008, Annex I section 3.4.