2,2'-iminodiethanol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

OECD 406 skin sensitisation available

Test material

Test material information

1

Reference substance name:

2,2'-iminodiethanol

EC Number:

203-868-0

EC Name:

2,2'-iminodiethanol

Cas Number:

111-42-2

Molecular formula:

C4H11NO2

IUPAC Name:

2,2'-iminodiethanol

Details on test material:

- Name of test material (as cited in study report): Diethanolamine
- Physical state: liquid, colorless
- Analytical purity: 99.5%
- Lot/batch No.: Probe 917
- Stability under test conditions: stable for at least 2 hours in physiological saline
- Source: BASF AG, Germany

In vivo test system

Test animals

Species:

guinea pig

Strain:

Himalayan

Sex:

female

Details on test animals and environmental conditions:

- Source:  BRL, Fuellingsdorf, Switzerland
- Age at study initiation: 8 weeks
- Weight at study initiation: 324 - 342 g (mean)
- Diet: ad libitum
- Water: ad libitum
- Acclimation period:

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

physiological saline

Induction 2

Concentration / amount:

Range finding tests: intradermal (1, 3, 5%); dermal (25, 50, 75, 100%)
Induction: intradermal (5% in saline and 5% in Saline/FCA); dermal (25,50,75,100%)
Challenge: dermal (25%)

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

physiological saline

Challenge 2

Concentration / amount:

Range finding tests: intradermal (1, 3, 5%); dermal (25, 50, 75, 100%)
Induction: intradermal (5% in saline and 5% in Saline/FCA); dermal (25,50,75,100%)
Challenge: dermal (25%)

No. of animals per dose:

40 femals in total and additional 6 females for pretests;
10 animals for control group 1
10 animals for control group 2
20 animals for test group
2 females for the  intracutaneous pretest  
4 females for the epicutaneous pretest.

Details on study design:

For the identification of irritant test substance concentration suitable for the induction phase, intradermal injections (0.1 ml/site) were made into the clipped flank of 2 animals at concentrations of 1%, 3% and 5% dissolved in physiological saline. The dermal reactions were assessed 24 hours later.  For epidermal applications patches of filter paper (2 cm x 2 cm) were saturated with the undiluted test substance (100%) and with preparations in physiological saline of 25%, 50%, 75%% and were applied occlusively to  the clipped and shaved skin of 4 animals. The dressings were removed  after 24 hours and investigated for erythema and edema and  re-investigated after 48 hours.

MAIN STUDY
A1. INDUCTION EXPOSURE (intrademal injections)
- No. of exposures: 3 pairs of intradermal injections (0.1 ml/site)
- Exposure period: 24 hours
- Test groups: 1) Freund's complete adjuvant 50 :50 with bi-distilled water.
2) The test article, diluted to 5 % with physiological saline.
3) The test article at the concentration used in (2), emulsified in a 50 :50 mixture of Freund's complete adjuvant and the vehicle ued i n (2) .
- Control group: 1) Freund's complete adjuvant 50 :50 with bi-distilled water.
2) Vehicle used in (2) for test group .
3) Freund's complete adjuvant 50 :50 with bi-distilled water.
- Site: clipped dorsal skin
- Frequency of applications:
- Duration: 24 h after injections reactions were assessed


A2. INDUCTION EXPOSURE (epidermal application)
- No. of exposures: single exposure with Patches of 2 x2 cm in size saturated with the test compound at different concentrations
- Exposure period: 24 hours
- Frequency of applications: epicutaneous application was made one week after intradermal induction
- Duration: 72 h (24h exposure, then substance removal and first reading; second and third readings 24h and 48h after substance removal)
- Concentrations: 100, 75, 50, 25 %


B. CHALLENGE EXPOSURE
- No. of exposures: 2 patches of 2 x2 cm in size saturated with the test compound were applied to the right and the left flank skin
- Day(s) of challenge: two weeks after the epidermal induction application
- Exposure period: 24 h
- Test groups: all test groups challenged with the test substance
- Control group: control group 1 challenged with the test substance, control group 2 left untreated
- Site: shaved flank skin
- Concentrations: non-irritant concentration (25% in saline)
- Evaluation (hr after challenge): immediately after patch removal, 24h and 48h later


OTHER: Scoring
The reactions were scored according to the following numerical grading system according to Draize:

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

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

Challenge controls:

1) Freund's complete adjuvant 50 :50 with bi-distilled water.
2) Vehicle used in (2) for test group.
3) Freund's complete adjuvant 50 :50 with bi-distilled water.

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

induction period: 20 % dilution of formaldehyde in bi-distilled water, challenge procedure: 15 % dilution of formaldehyd was used

No. with + reactions:

7

Total no. in group:

10

Clinical observations:

erythema

Remarks on result:

other: A control group (Formaldehyde-solution) is tested twice a year for sensitivity check of the guinea pig strain. Test was run from April 23 to May 24, 1990

Results 2

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25% test chemical in phys. saline

No. with + reactions:

2

Total no. in group:

20

Clinical observations:

erythema

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. No with. + reactions: 2.0. Total no. in groups: 20.0. Clinical observations: erythema.

Results 3

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25% test chemical in phys. saline

No. with + reactions:

1

Total no. in group:

20

Clinical observations:

erythema

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. No with. + reactions: 1.0. Total no. in groups: 20.0. Clinical observations: erythema.

Results 4

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

vehicle only

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no effects observed

Remarks on result:

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

Any other information on results incl. tables

Results of pretest:  
Based on the reactions of the pretest, the concentration of 5% was selected for intradermal injection for the main study

Based on the reactions of the pre-test with regards to epidermal application, the concentration selected for the induction was 75% and for  the challenge procedure was 25%.

Results of main test:  
No mortalities or toxic signs occurred.

Control group:
No positive skin reactions were evident after 1st challenge neither with when treated with physiological saline nor with 25% Diethanolamine.

Test group:
Only 2/20 (10%) showed erythema findings at 24 h readings, declining to 1/20 (5%) at 48 h reading when treated with 25% Diethanolamine. No further findings were noted.

Summary of skin reactions after challenge exposure:

Readings:	24 h	48 h
Control groups
75% epidermal DEA during induction	0/10	0/10
Phys. Saline during induction	0/10	0/10
Test group
25% DEA	2/20	1/20
Phys. saline	0/20	0/20

                                         
Body weights:

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

Systemic Symptomes:

No systemic symptomes were observed during the study.

Applicant's summary and conclusion

Interpretation of results:

not sensitising