2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate

Endpoint summary

Description of key information

Based on substance specific data and read-across from 2-(2-ethoxyethoxy)ethyl acetate (CAS 112-15-12):
Skin: not irritating
Eye: not irritating 

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 Aug 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant study conducted in accordance with internationally recognised test methods

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: in vitro test with bovine eyes

Strain:

other: not applicable

Details on test animals or tissues and environmental conditions:

TEST MATERIAL SOURCE AND TREATMENT
Eyes from adult cattle were obtained from a local abattoir as a by-product from freshly slaughtered animals. The eyes were excised by an abattoir employee and placed in Hanks’ Balanced Salt Solution (HBSS), supplemented with Penicillin/Streptomycin, and transported to the laboratory on ice packs. The corneas were prepared immediately on arrival.

PREPARATION OF CORNEAS
The cornea from each selected eye was removed leaving a 2-3 mm rim of sclera to facilitate handling. The iris and lens were peeledaway from the cornea. The isolated corneas were immersed in HBSS until they were mounted in Bovine Corneal Opacity and Permeability (BCOP) holders. The anterior and posterior chambers of each BCOP holder were filled with complete minimum essential medium (MEM) and plugged. The holders were incubated at 32 ±1ºC for 60 minutes. At the end of the incubation period each cornea was examined for defects and only corneas free of damage were used.

Vehicle:

unchanged (no vehicle)

Controls:

other: yes, positive and negative control items were included

Amount / concentration applied:

TEST MATERIAL AND CONTROL SUBSTANCES
- Amount(s) applied: 0.75 mL

Duration of treatment / exposure:

10 min (exposure with the test material)
120 ± 10 min (incubation in MEM)

Observation period (in vivo):

120 ± 10 min after exposure

Number of animals or in vitro replicates:

3 test corneas
3 negative control corneas
3 positive control corneas

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: At the end of the exposure period the test item and control items were removed from the anterior chamber and the cornea was rinsed three times with fresh complete MEM containing phenol red before a final rinse with complete MEM. The anterior chamber was refilled with fresh complete MEM. A post-treatment opacity reading was taken and each cornea was visually observed.
- Time after start of exposure: 120 ± 10 min

SCORING SYSTEM: In Vitro Irritancy Score = mean opacity value + (15 x mean OD492 value)

TOOL USED TO ASSESS SCORE: fluorescein

POSITIVE CONTROL SUBSTANCE: ethanol

NEGATIVE CONTROL SUBSTANCE: 0.9% (w/v) sodium chloride solution

PERMEABILITY DETERMINATION: 360 µL of medium representing each cornea was applied to a designated well on a 96-well plate and the optical density at 492 nm (OD492) was measured. The corrected OD492 was calculated by subtracting the mean OD492 of the negative control corneas from the OD492 value of each treated cornea. The OD 492 value of each treatment group was calculated by averaging the corrected OD492 values of the treated corneas for the treatment group.

OPACITY MEASUREMENT: The change in opacity for each cornea was calculated by subtracting the initial opacity reading from the final opacity reading (corrected for the average change in opacity observed for the negative control corneas). The mean opacity value of each treatment group was then calculated by averaging the corrected opacity values of each cornea for that treatment group.

HISTOPATHOLOGY: The corneas were retained after testing for possible conduct of histopathology (in 10% neutral buffered formalin).

VISUAL OBSERVATION: The condition of the cornea was visually assessed immediately after rinsing and at the final opacity measurement.

Irritation parameter:

other: In Vitro Irritancy Score

Basis:

other: Negative Control

Time point:

other: 120 min

Score:

3.5

Irritation parameter:

other: In Vitro Irritancy Score

Basis:

other: Test item

Time point:

other: 120 min

Score:

0.4

Irritation parameter:

other: In Vitro Irritancy Score

Basis:

other: Positive Control

Time point:

other: 120 min

Score:

37.6

Irritant / corrosive response data:

The corneas treated with the test item were clear post treatment and post incubation.
The corneas treated with the negative control item were clear post treatment and post incubation.
The corneas treated with the positive control item were cloudy post treatment and post incubation.

Table 1. Individual and Mean Corneal Opacity and Permeability Measurements.

Treatment	Cornea number	Opacity					Permeability		In vitro Irritancy score
		Pre-T	Post-T	Post-I	Post-I – Pre-T	Corrected value		Corrected value
Negative control	13	1	3	5	4	-	0160	-	-
	14	1	2	2	1	-	0.176	-	-
	15	1	1	1	0	-	0.035	-	-
	-	-	-	-	1.7*	-	0.124#	-	3.5
Positive control	10	0	18	20	20	18.3	1.290	1.166	-
	11	2	34	35	33	31.3	1.053	0.929	-
	12	0	22	24	24	22.3	0.747	0.623	-
	-	-	-	-	-	24.0**	-	0.906**	37.6
Test item	16	1	4	2	1	0.0	0.028	0.000	-
	17	1	4	2	1	0.0	0.027	0.000	-
	18	3	7	6	3	1.3	0.043	0.000	-
	-	-	-	-	-	0.4**	-	0.000**	0.4

Pre-T: Pre-treatment, Post-T: Post-treatment, Post-I: Post-incubation

*: Mean of the post incubation – pre-treatment values

# = Mean permeability

** = Mean corrected value

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified

Executive summary:

Potential eye irritation/corrosion has been investigated in an in-vitro BCOP assay using OECD test methods. In accordance with the decision criteria for classification and labelling, as given in OECD guideline 437 (adopted 26 July 2013), the results indicate that the substance does not need to be classified.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Justification for grouping of substances and read-across

There are only limited data available on the skin irritating potential of 2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate (CAS 111-21-7). In order to fulfil the standard information requirements set out in Annex VIII, 8.1, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from a structurally related substance is conducted.

In accordance with 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).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 whereby physicochemical, toxicological and ecotoxicological properties may be predicted from data for reference substance(s) by interpolation to other substances on the basis of structural similarity, 2-(2-ethoxyethoxy)ethyl acetate (CAS 112-15-2) is selected as reference substances for assessment of skin irritation.

The read-across is based on the structural similarity between the source and target substances which are both esters of similar di-functional alcohols with the carboxylic acid acetic acid. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Overview of skin irritation / corrosion

CAS#	111-21-7 (a)	112-15-2 (b)
Chemical name	2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate	2-(2-ethoxyethoxy)ethyl acetate
Molecular weight (g/mol)	234.25	176.21
Skin irritation	RA CAS 112-15-2	Experimental result: Not irritating

(a) The substance subject to the REACh Phase-in registration deadline of 31 May 2013 is indicated in bold font. Only for this substance a full set of experimental results and/or read-across is given.

(b) Reference (read-across) substances are indicated in normal font.

Skin irritation/corrosion

Only one study with limited data is available investigating the skin irritation properties of 2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate (CAS 111-21-7) (Union Carbide, 1967). In this study, the undiluted test material was applied to rabbit skin (no further information). No irritation occurred in all animals and no other effects were reported. In order to fulfil the standard information requirements set out in Annex VIII, 8.1, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006 read-across from the structurally related analogue substance 2-(2-ethoxyethoxy)ethyl acetate (CAS 112-15-2) is conducted. In a study conducted according to OECD guideline 404 (Mürmann, 1990), 3 male rabbits were exposed to 0.5 cm³ of the unchanged test substance, applied to the shaved skin for 4 h using a semiocclusive dressing. The treated skin was observed and evaluated at 1, 24, 48 and 72 h post-application. Very slight erythema was observed in 2/3 animal being reversible within 6 days h (mean erythema score out of all 3 animals over 24, 48 and 72 h: 0.6). Very slight edema was observed in one animal after 1 h, only. Thus, no skin irritating properties of 2-(2-ethoxyethoxy)ethyl acetate were apparent.

 

Eye irritation/corrosion

The potential of 2,2'-[ethane-1,2 -diylbis(oxy)]bisethyl diacetate (CAS 111 -21 -7) to cause severe eye irritation/corrosion has been investigated in an in-vitro BCOP assay using OECD test methods under GLP conditions (Warren, 2013). The undliuted test item was applied for 10 minutes followed by an incubation period of 120 minutes. Negative and positive control items were tested concurrently. The two endpoints, decreased light transmission through the cornea (opacity) and increased passage of sodium fluorescein dye through the cornea (permeability) were combined in an empirically derived formula to generate the In Vitro Irritancy Score (IVIS). The IVIS for the test item, the negative control and the positive control were 0.4, 3.5 and 37.6, respectively. A test item that induces an IVIS ≥55.1 is defined as an ocular corrosive or severe irritant. The results indicate that the substance is not corrosive or severely irritant to the eye. In accordance with the decision criteria for classification and labelling, as given in OECD guideline 437 (adopted 26 July 2013), the results indicate that the substance is not irritating to eyes, having an IVIS score of <3. A publication with limited data reporting an investigation of the eye irritation properties of 2,2'-[ethane-1,2-diylbis(oxy)]bisethyl diacetate (CAS 111-21-7) in rabbits is available (Union Carbide, 1967). A total of 5 rabbits were treated by application of the undiluted substance into the eye. In four animals, no effect on the overall irritation was observed although a trace of corneal injury was apparent in the fifth animal. No further information on the severity of reversibility of this response is available. According to the author, the test substance was essentially non-irritating when instilled in excess amounts in rabbit eyes and no further effects were reported.

 

Conclusion for skin and eye irritation

Based on the available data there is no indication that 2,2'-[ethane-1,2 -diylbis(oxy)]bisethyl diacetate (CAS 111-21-7) is a concern for skin or eye irritation/corrosion.

Justification for selection of skin irritation / corrosion endpoint:
Hazard assessment is conducted by means of read-across from a structural analogue and from substance-specific data and based on the weight of evidence from all available studies.

Justification for selection of eye irritation endpoint:
There is one key study available.

Justification for classification or non-classification

Based on substance specific data and read-across from the source substance 2-(2-ethoxyethoxy)ethyl acetate (CAS 112-15-2) following an analogue approach, the available data on skin irritation do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and the data are therefore conclusive but not sufficient for classification.

 

Based on substance specific data, and in accordance with the decision criteria for classification and labelling, as given in OECD guideline 437 (adopted 26 July 2013), the results indicate that the available data on eye irritation 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.