2,2'-oxydiethanol

Endpoint summary

Description of key information

The test item is considered to possess no skin or eye irritating properties.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

Basic information is given.

Principles of method if other than guideline:

Draize Test: test procedure as described in the Journal Officiel de la République Francaise.

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: about 2.5 kg
- Housing: in individual cages
- No further details provided

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

0.5 mL

Duration of treatment / exposure:

23 h

Number of animals:

6 males

Details on study design:

TEST SITE
- Area of exposure: 4 cm x 4 cm; application area with and without scarification
- Type of wrap if used: occlusive patches "Neodermotest", fixed using absorbent gauze held in place by adhesive tape.

SCORING SYSTEM: Draize-score system; determination of the primary cutaneous irritation index.
- The substance was considered to be a non irritant if the score was less than 0.5
- The substance was considered to be slightly irritant if the score was between 0.5 and 2.0

Irritation parameter:

other: mean maximum cutaneous index

Basis:

mean

Time point:

other: no data

Score:

0.04

Remarks on result:

other: undiluted DEG

Irritation parameter:

other: mean maximum cutaneous index

Basis:

mean

Time point:

other: 6 weeks

Score:

0.47

Remarks on result:

other: undiluted DEG

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 6 weeks

Score:

0

Remarks on result:

other: 10% solution

Irritant / corrosive response data:

Undiluted DEG: PII: 0.04; 6 -week cumulative cutaneous irritation: well tolerated (MMII = 0.47)
10% solution: 6 -week cumulation cutaneous irritation: very well tolerated (MMII = 0)

PII = primary cutaneous irritation index;
MMII = mean maximum cutaneous index.

In their pure form, humectants are particularly well tolerated in primary cutaneous irritation for nearly all these indices approximate to 0 and so correspond to a non-irritant application.

Interpretation of results:

GHS criteria not met

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF SE Experimental Toxicology and Ecology 67056 Ludwigshafen, Germany

Specific details on test material used for the study:

- Name of test substance : 2,2'-oxydiethanol
- Test-substance No.: 07/0335-4
- Batch identification : OOOSTD77LO
- CAS No.:111-46-6
- Purity: min. 99.85 % (analytical results given by the sponsor per mail)
- An analytical characterization of the test substance according to GLP has been performed.
- ldentity: Confirmed
- Homogeneity: The test substance is homogeneous by visual inspection.
- Storage stability: The sponsor guarantees the storage stability at least until 08 Oct 2016.
- pH-value: Ca. 5 (undiluted test substance; determined in the lab prior to start of the GLP study)
- Physical state I color: Liquid I colorless clear
- Storage conditions : Room temperature, avoid temperatures > 40 °C; under light exclusion, protected against humidity.

Test system:

human skin model

Source species:

human

Cell type:

other: Three dimensional human epidermis model

Vehicle:

physiological saline

Details on test system:

THREE DIMENSIONAL HUMAN EPIDERMIS MODEL
The EpiDermTM model cinsists of normal, human-derived epidermal keratinocytes which have been cultured for a multilayered, highly differentiated model of the human epidermis. It sonsists of organized basal, spinous and granular layers, and multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous tothose found in vivo. The EpiDerm TM tissues (surface 0.6 cm2) are cultured on cellular inserts (MILLICELLS R, 10mm2) and are commercially available as kits (EpiDermTM200), containing 24 tissues on shipping agarose.

The test was performed under sterile conditions working at a laminar flow hood. All materials used were sterilized if possible or disinfected with 70% isopropanol.

1. PREINCUBATION OF THE TISSUES
On the day of arrival in the laboratory, the tissues were transferred to sterile 6-well plates with 0.9 ml assay medium and preconditioned in the incubator at 37°C. After 1 hour the pre-incubation medium was replaced with fresh medium and preconditioning continues for 18 ± 3 hours.

2. APPLICATION OF THE TEST SUBSTANCE
Three tissues were treated with each test substance , the PC and NC, respectively. Three additional tissues (KC) were used for the test substance and the NC, respectively; if a positive reaction has been observed in the MTT reduction test described under 5.
Thirty microliters (30 µL) of the undiluted liquid test substance were applied using a pipette. lf applicable a nylon mesh was placed carefully onto the tissue surface afterwards.
Control tissues were concurrently treated with 30 µL sterile PBS (NC, NC KC (if applicable)) or 5% SOS (PC) or test substance (KC, if applicable). After application a nylon mesh was placed carefully onto each tissue surface of the NC and PC and if applicable NC KC and test substance KC.
The tissues were kept under the laminar flow hood at room temperature for 25 minutes overall and for 35 minutes in the incubator .
The tissues were washed with sterile PBS to remove residual test material 1 hour after start of application. Rinsed tissues were blotted on sterile absorbent paper and transferred into new 6-well plates, pre-filled with 0.9 mL fresh medium. When all tissues were rinsed, the surface of each tissue was carefully dried with a sterile cotton swab.
Subsequently, the tissues were incubated in the incubator at 37°C for 24 ± 2 hours.

3. MEDIUM CHANGE
After 24 ± 2 hours the tissues were transferred into new 6-well plates pre-filled with 0.9 mL of fresh medium and placed into the incubator for additional 18 ± 2 hours post-incubation period.

4. MTT incubation
After the postincubation period,the assay medium was replaced by 0.3 mL MTT solution and the tissues were incubated in the incubator for 3 hours. After incubation, the tissues were washed with PBS to stop the MTT-incubation.

5. DETECTION OF MTT METABOLISM
The formazan that is metabolically produced by the tissues was extracted by incubation of the tissues in 2 mL isopropanol for at least 2 hours at room temperature on a plate shaker (ca. 120 rpm). After shaking the isopropanol extract and piercing the tissues, 2 aliquots of each extract per tissue were transferred to a 96-well microtiter plate. The optical density (00510) was determined spectrophotometrically using a filter with a wavelength of 570 nm.

Control samples:

yes, concurrent vehicle

yes, concurrent positive control

Amount/concentration applied:

30 µL per well

Duration of treatment / exposure:

24 ± 2 hours

Duration of post-treatment incubation (if applicable):

18 ± 2 hours

Number of replicates:

3

Irritation / corrosion parameter:

% tissue viability

Value:

94.5

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

no indication of irritation

 

Test substance identification		tissue 1	tissue 2	tissue 3	mean	SD	CV [%]
NC	mean OD570	2,330	2,267	2,599	2,399
	viability [% of NC]	97,1	94,5	108,3	100,0	7,3	7,3
07/0335-4	mean OD570	2,696	2,000	2,107	2,268
	viability [% of NC]	112,4	83,4	87,8	94,5	15,6	16,5
PC	mean OD570	0,074	0,072	0,072	0,072
	viability [% of NC]	3,1	3,0	3,0	3,0	0,0	1,6

NC = negative control

PC = positive control

07/0335-4 = test substance 2,2'-oxydiethanol

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Estimation of eye hazard within a range-finding test.

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

no data

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

0.5 mL undiluted diethylene glycol

Duration of treatment / exposure:

24 hour(s)

Observation period (in vivo):

no data

Number of animals or in vitro replicates:

5

Details on study design:

The individual numerical scores of each eye treated were added together and then divided by the number of treated eyes (usually 5 animals) to obtain the score of the injury caused by the treatment. The level of 5.0 was selected by the authors of the study as representative of severe injury.
When a test is to be performed, normal albino rabbits are selected on the basis of absence of grossly visible staining of the eye by a 5% aqueous solution of fluorescein sodium, flushed with distilled water 20 seconds after application. After a two-hour interval to allow the eye to return normal, the undiluted material is applied to the centre of the cornea while the lids are retracted. Eighteen to 24 hours later, the eye is examined in strong diffuse daylight, and then stained with fluorescein, and the injury scored. Guided by the result and the table of injury grades, additional applications are made until the chemical can be assigned to one of the grades they recognize.

Irritation parameter:

other: ocular irritation

Basis:

mean

Remarks:

all animals

Time point:

24 h

Score:

1

Max. score:

10

Reversibility:

not specified

Remarks on result:

other: 0.5 mL 0.5 mL undiluted gives injury of 0 to 1.0 points

Remarks:

Grade 1

Irritant / corrosive response data:

No occular irritation was noticed after application of 0.5 mL of undiluted test item.

Interpretation of results:

GHS criteria not met

Reference 2

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

Basic information is given.

Principles of method if other than guideline:

The ocular tolerance of the test item was evaluated on six male albino rabbits. Reading of the treated eyes was done after 1 h, 24 h, 2 days, 3 days, 4 days and 7 days following application. The findings were evaluated using the evaluation scale of 0 to 110 by Kay and Calandra (J Soc Cosmet Chem 13: 281–289, 1962, modified).

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Diethylene glycol

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- 6 males albino rabbits were used.
- Weight at study initiation: 2.5 kg
- No further details given.

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

Diethylene glycol at test concentrations ranging from 10 to 100%
Amount applied: 0.1 mL

Duration of treatment / exposure:

The eyes were not washed.

Observation period (in vivo):

7 days
Reading time points: after 1 h, 24 h, 2 days, 3 days, 4 days and 7 days.

Number of animals or in vitro replicates:

6

Details on study design:

SCORING SYSTEM:
The ocular irritation index was determined. A compound is considered to not provoke any significant injury to the eye mucous membrane when no opacity of the cornea occurs and when the occular index is less than 15.

TOOL USED TO ASSESS SCORE: fluorescein for examination of corneal opacity

Irritation parameter:

overall irritation score

Basis:

mean

Remarks:

all animals

Score:

11.67

Max. score:

110

Reversibility:

not specified

Remarks on result:

no indication of irritation

Remarks:

the test item resulted in an ocular index below 15, and there was no indication for corneal opacity.

Irritant / corrosive response data:

The test item resulted in an ocular index of 11.67 which was below 15, and there was no indication for corneal opacity. Thus, the test item was not irritating to the eye of rabbit under the test conditions used.

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

Skin irritation

In a study conducted according to Draize, rabbits received occlusive skin applications of the undiluted test material diethylene glycol for 23 hours (Guillot et al., 1982). No skin reactions were noticed. When tested on human volunteers under occluded conditions (human occluded patch test; Monsanto, 1970), diethylene glycol was found to be a mild irritant and the slight skin findings were fully reversible within less than 24 hours.

 

Diethylene glycol was further tested in a reconstructed human epidermal model EpiDerm TM, according to OECD Guideline 439 (BASF, 2016). The objective of this in vitro method is to assess the skin irritation potential of the test substance. Available information on toxicological and physico-chemical properties of the test substance2,2'-oxydiethanol including considerations concerning structure-activity-relationships did not indicate an irritation potential of the substance. Thus, the EpiDerm™ Skin irritation test was performed. The test substance was topically exposed to the surface of a human reconstituted epidermis model for 1 hour followed by a cell viability test. The optical density of the extracts of the test substance treated tissue was compared to negative control values from treated tissue with PBS and is expressed as relative tissue viability. The relative tissues viability was 94.5 % and therefore 2,2'-oxydiethanol was clearly not irritant.

 

Eye irritation

Carpenter and Smyth (1946) tested diethylene glycol for eye irritation and applied 0.5 mL of undiluted test item into the eyes of rabbits; readings of the treated eyes revealed no signs of ocular irritation due to the treatment with 0.5 mL of undiluted test item. In a more recent publication by Guillot et al. (1982), the irritating potential of diethylene glycol to the eye was evaluated by application of 0.1 mL of test item at test concentrations ranging from 10 to 100%, into the eye of 6 male albino rabbits. Reading of the treated eyes was done after 1 h, 24 h, 2 days, 3 days, 4 days and 7 days following application. The findings were evaluated using the evaluation scale of 0 to 110 by Kay and Calandra (J Soc Cosmet Chem 13: 281–289, 1962, modified). The test item resulted in a mean ocular index of 11.67 which was below 15, and there was no indication for corneal opacity. Thus, the test item was not irritating to the eye of rabbit under the test conditions used.

 

Respiratory irritation

No animal study is available.

 

To determine whether an atmosphere containing aerosolized ethylene glycol in a concentration that could be tolerated by human volunteers for most of each 24-h period would have any deleterious action on man, in a prison hospital twenty volunteers were exposed during 20 to 22 h per day to aerosolized ethylene glycol in mean daily concentrations between 3 and 67 mg/m3 (Wills, 1974; please also refer to section "Exposure related observations in humans" - IUCLID chapter 7.10).

Nineteen men finished the planned one-month exposure. When the concentration of ethylene glycol within the chamber was raised to 200 or more mg/m3, the atmosphere could not be tolerated for more than a minute or two, the period of tolerance decreasing progressively as the concentration was increased further. Blood and urine specimens obtained from the volunteers at intervals during their prolonged exposure gave little evidence of the absorption of important quantities of ethylene glycol. No subject experienced any serious signs of toxicity assignable to the exposure, but there were complaints of irritation of the throat and fauces. Slight headache and low backache also were reported occasionally. The irritative phenomena became common when the concentration of ethylene glycol in the ambient air was raised to about 140 mg/m3. The irritative effects appear to rule out the possibility that a harmful amount of ethylene glycol could be absorbed from the respiratory tract of a healthy Individual who was unaware that he had been exposed to this substance.

Justification for classification or non-classification

Based on the available information classification for skin, eye and respiratory irritation is not warranted in accordance with EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008.