Diammonium dihydrogen ethylenediaminetetraacetate

Endpoint summary

Description of key information

Diammonium dihydrogen ethylenediaminetetraacetate is not irritating to the skin (Dow Chemicals, 1982). No studies on eye irritation of diammonium dihydrogen ethylenediaminetetraacetate are available. However, several studies using EDTA free acid or its sodium salts have been performed. As the irritating effect is influenced by the pH it is reasonable to assume that the eye irritating effect of (NH4)2 EDTA (pH 4.5 -5.3) is less than the eye irritating effect of the alkaline Na4EDTA salt (pH =11). Therefore, a read-across to Na2H2EDTA with a similar pH value (pH 4-5) was employed.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: 16 CFR 1500.11

GLP compliance:

not specified

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dutchland Rabbit Farms
- Weight on receipt: 1.6-2.1 kg
- Housing: Standard conditions
- Diet: Big Red Rabbit Chow, ad libitum
- Water: City water, ad libitum
- Acclimation period: 2 week acclimation period

The rabbits were housed and all experiments performed in the facilities of the Vivarium of the University of Rochester School of medicine and dentistry which was accredited by the Association for the Accreditation for Animal care since 1966.

Type of coverage:

occlusive

Preparation of test site:

abraded

Remarks:

intact

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 500 mg to each test site

Duration of treatment / exposure:

24 hours

Observation period:

One week

Number of animals:

6 male rabbits

Details on study design:

TEST SITE
The animals were clipped on their sides 24 hours before the experiment. Two experimental areas, each measuring 25x25 mm, were prepared on each animal; one site was left intact, the other one abraded by means of shallow incisions through the stratum corneum without causing bleeding.
- Type of wrap if used: 500 mg of the undiluted test material were applied to each test site by means of double layer of surgical gauze which was then covered by overwrapping with pure latex rubber dental dam and the site was immobilized by means of adhesive bandage.

SCORING SYSTEM:
see the attachment 'Scoring System' below.

Irritation parameter:

edema score

Basis:

mean

Remarks:

Animal no.1 to 6 (intact)

Time point:

24 h

Score:

1.33

Max. score:

4

Reversibility:

fully reversible within: 3 days

Irritation parameter:

edema score

Basis:

mean

Remarks:

Animal no. 1 to 6 (intact)

Time point:

72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 3 days

Irritation parameter:

edema score

Basis:

mean

Remarks:

Animal no.1 to 6 (abraded)

Time point:

24 h

Score:

2

Max. score:

4

Reversibility:

other: Reversible in 5 animals out of 6 within 3 days

Irritation parameter:

edema score

Basis:

mean

Remarks:

Animal no. 1 to 6 (abraded)

Time point:

72 h

Score:

0.17

Max. score:

4

Reversibility:

other: Reversible in 5 animals out of 6 within 3 days.

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Animal no.1 to 6 (intact)

Time point:

24 h

Score:

1.5

Max. score:

4

Reversibility:

fully reversible within: 3 days

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Animal no.1 to 6 (intact)

Time point:

72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 3 days

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Animal no.1 to 6 (abraded)

Time point:

24 h

Score:

1.83

Max. score:

4

Reversibility:

other: Reversible in 5 animals out of 6 within 3 days.

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Animal no. 1 to 6 (abraded)

Time point:

72 h

Score:

0.17

Max. score:

4

Reversibility:

other: Reversible in 5 animals out of 6 within 3 days.

Irritant / corrosive response data:

The primary irritation score was 1.75. The score indicates that the test material is not corrosive and dose not cause permanent skin damage under the test conditions. The animals were observed for an additional week. The only observable effect was gradual healing of residual skin changes, if any.

Other effects:

No systemic effects were observed in any of the animals either during the experiment period or afterwards.

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

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

2002

Deviations:

yes

Remarks:

dose not exactly specified (OECD: volume of 0.1 mL); 2 animals are used (OECD: 3); examination using fluorescein (OECD: no use of fluorescein)

Principles of method if other than guideline:

BASF-TEST: Before OECD guideline 405 was established, eye irritation was tested using an internal method. White Vienna rabbits were used. Usually approximately 50 mg of the test substance were applied to the conjunctival sac of one eye of 2 animals. In studies with solids, talcum powder was used as control. The animals were observed several times on the treatment day and up to 8 days afterwards, and findings were recorded on working days.
The eyes were not washed out after 24 h as specified in OECD Guideline 405, which could be critical for solids which thus remained on the cornea for several days, causing mechanical damage. Probably, this would have been less severe if it had been washed out after 1 day.

GLP compliance:

no

Species:

rabbit

Strain:

Vienna White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 3.39; 3.15 kg

Vehicle:

unchanged (no vehicle)

Controls:

other: talcum treated eye of the same animal

Amount / concentration applied:

- Amount applied: a sharp spoon (probably approximately 50 mg)

Duration of treatment / exposure:

- substance was not washed out

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

2

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: no washing was done

READING TIME POINTS
10 min, 1 h, 3 h, 24 h, 48 h, 72 h, 6 days and 8 days after application; however the data on the 48 h, 72 h and 6 days reading of animal 2 are not reported.

READING TIME POINTS USED FOR ASSESSMENT
24, 48 and 72 h for animal 1; 24 h for animal 2

SCORING SYSTEM:
For the evaluation the BASF scores given in the raw data were converted to Draize scores

TOOL USED TO ASSESS SCORE: fluorescein

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 24 - 48 - 72 h for animal 1; 24 h for animal 2

Score:

0.5

Max. score:

3

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.3

Max. score:

3

Reversibility:

fully reversible within: 48 h

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 8 days

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

Both animals showed some redness of the conjunctivae (score 1), 24 h after application of the TS. The same effect was observed in the talcum powder treated eye. This effect was fully reversible 48 h in animal 1 and at least within 8 days in animal 2.

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation

A sample of the test material (a clear colorless liquid) was submitted for primary skin potential in rabbits according to the experimental procedures described in 16 CFR 1500.11 (formerly 21 CFR 191.11). 6 male New Zealand White albino rabbits weighing between 1.6 and 2.1 kg on receipt were used. Animals were acclimatized were for a two week period and were maintained on Big Red Rabbit Chow and city water ad libitum. The animals were prepared by clipping their sides with an electric clipper 24 hours before the experiment. Two experimental areas, each measuring 25×25 mm, were prepared on each animal; one site was left intact, the other one was baraded by means of shallow incisions through the stratum corneum without causing bleeding. 500 mg of the undiluted test material were applied to each test site by means of a double layer of surgical gauze which was then covered by over wrapping with pure latex rubber dental dam and the site was immobilized by means of adhesive bandages. All bandages, sheeting, gauze, etc. were removed 24 hours after application. All skin changes, if any, were observed, scored and recorded according to the prescribed procedure at this time, and again at 72 hours after the time of application. The animals were then observed for an additional week. The only observable effect was gradual healing of residual skin changes, if any. No systemic effects were observed in any of the animals, either during the experimental period or afterwards. The primary dermal irritation score was 1.75. So the test material is classified as not irritating to skin according to EU criteria (Dow Chemicals, 1982).

In a skin irritation study performed by BASF (1973) two rabbits were exposed occlusively for 1, 5 or 15 minutes on the back to a 50% aqueous solution of edetic acid. Two additional rabbits were exposed to the same solution for 20 h on the back and at the ear. The skin of the animals was observed for 8 days. No skin irritation was observed on the back of the animals at any exposure period tested. Solely a slight erythema could be observed on the ear of the animals which was fully reversible within 48 h.

Another skin irritation study which was performed according to OECD guideline 404. Two male and 1 female rabbits were exposed to 0.5 g of an 80% aqueous preparation of Trilon B Powder (edetic acid tetrasodium salt, 80% aqueous preparation) for an occlusive exposure period of 4 hours. For erythema medium scores after 24/48/72 hours of 1/0/0.3 were documented, redness had resolved after 8 days. No edema was noted (BASF, 1982).

In a skin irritation study performed by BASF (1973) two rabbits were exposed occlusively for 1, 5 or 15 minutes on the back to a 50% aqueous solution of Na2EDTA. Two additional rabbits were exposed to the same solution for 20 h on the back and at the ear. The skin of the animals was observed for 7 days. Both animals developed a mild erythema 24 h after application (grad 1 or grade 2 respectively) which was fully reversible within 48 or 72 h. No edema was observed. A well-defined erythema was observed on the ear of both animals, which was fully reversible within 48 h.

Eye irritation

In an eye irritation study (BASF, 1973) with Na2EDTA White Vienna rabbits were used. Approximately 50 mg of the test substance were applied to the conjunctival sac of one eye of 2 animals. The other eye served as control and was treated with 50 mg talcum powder. The test substance was not washed out and the animals were observed for 8 days. A slight redness of the eye (scale 1) was observed in both animals, which was fully reversible within 8 days.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the substance is not considered to be classified for skin/eye irritation/corrosion under Regulation (EC) No 1272/2008, as amended for the ninth time in Regulation EC No 2016/1179.