2-Propenoic acid, methyl ester, reaction products with 2-ethyl-1-hexanamine and sodium hydroxide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 - 16 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Reference

Endpoint:

acute toxicity: dermal

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The read-across hypothesis is based on “different compounds which have similar properties”.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
- The source substance is identified as Sodium N-(2-carboxyethyl)-N-(2-ethylhexyl)-β-alaninate, also known as Sodium 3-[(2-carboxyethyl)(2-ethylhexyl)amino]propanoate (CAS no. 94441-92-6 | EC no. 305-318-6). It is a UVCB substance whose major constituent is sodium 2-ethylhexylimino-di-propionate. Minor constituents are sodium 2-ethylhexylimino-mono-propionate, unreacted acrylic acid and unreacted 2-ethylhexylamine.
- The target substance is identified as Propenoic acid, methyl ester, reaction products with 2-ethyl-1-hexanamine and sodium hydroxide (methanol free) (CAS no. 68610-44-6| EC no. 271-865-1). It is a UVCB substance whose major constituents are sodium 2-ethylhexylimino-mono-propionate and sodium 2-ethylhexylimino-di-propionate. Minor constituents are unreacted acrylic acid and unreacted 2-ethylhexylamine.

3. ANALOGUE APPROACH JUSTIFICATION
The target and source substances are essentially the same: both are UVCB substances composed of the exact same constituents with the exact same functional groups (i.e. carboxylic acid groups and secondary/tertiary amine groups). They are expected to have the same ADME profile and to share common mode of action and breakdown products. The target and source substances only differ in the overlapping ranges of their constituents, the content of sodium 2-ethylhexylimino-mono-propionate being especially higher in the target substance. This difference is expected to have no or very limited impact on the potency of effects exerted on exposed living organisms.

4. DATA MATRIX
Cf. read-across justification document attached in §13. Assessment reports.

Reason / purpose for cross-reference:

read-across source

Key result

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

act. ingr.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nohsan, Notification No 8147, April 2011; including the most recent partial revisions.

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Sodium N-(2-carboxyethyl)-N-(2-ethylhexyl)-β-alaninate

EC Number:

305-318-6

EC Name:

Sodium N-(2-carboxyethyl)-N-(2-ethylhexyl)-β-alaninate

Cas Number:

94441-92-6

Molecular formula:

C14H26NO4.Na

IUPAC Name:

sodium 3-[(2-carboxyethyl)(2-ethylhexyl)amino]propanoate

Constituent 2

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Water

Test material form:

liquid

Remarks:

Clear amber

Details on test material:

- Name of test material (as cited in study report): Sodium N-(2-carboxyethyl)-N-(2-ethylhexyl)-ß-alaninate
- Substance type: Clear amber liquid
- Physical state: liquid
- Composition: confidential information
- Lot/batch No.: confidential information
- Expiration date of the lot/batch: confidential information
- Storage condition of test material: At room temperature in the dark
- Volatile: No
- Density: 1.081 kg/m3 at 20°C
- pH: 8.5-9.5 at 20% solution

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: Young adult animals (approx. 10 weeks old)
- Weight at study initiation: Body weight variation was within +/- 20% of the sex mean (males: 271 grams; females: 186 grams).
- Housing: Individual housing in labeled Macrolon cages
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, approximately 15 room air changes/hour, and a 12-hour light/12-hour dark cycle.

IN-LIFE DATES: From: 02 - 16 May 2012

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

One day before exposure (Day -1) an area of approximately 5x7 cm on the back of the animal was clipped.

The test substance was applied in an area of approx. 10% of the total body surface, i.e. approx. 25 cm² for males and 18 cm² for females. The test substance was held in contact with the skin with a dressing, consisting of a surgical gauze patch (Surgy 1D)*, successively covered with aluminum foil and Coban elastic bandage*. A piece of Micropore tape* was additionally used for fixation of the bandages in females only. *. Manufacturers: Laboratoires Stella s.a., Liege, Belgium (surgical gauze) and 3M, St. Paul, Minnesota, U.S.A. (Coban & Micropore).

Frequency: Single dosage, on Day 1.

Washing: Following application, dressings were removed and the skin cleaned of residual test substance using tap water.

Duration of exposure:

24 hours.

Doses:

2000 mg/kg (4.63 mL/kg) body weight. Dose levels were corrected for a purity of 40%.

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

Dose volume: 4.63 mL/kg

Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: Twice daily.
Body weights: Days 1 (pre-administration), 8 and 15.
Clinical signs: At periodic intervals on the day of dosing (Day 1) and once daily thereafter, until Day 15.
- Necropsy of survivors performed: At the end of the observation period, all animals were sacrificed by oxygen/carbon dioxide procedure and subjected to necropsy. Descriptions of all internal macroscopic abnormalities were recorded.
- Other examinations performed: none.

Statistics:

None.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Hunched posture and/or chromodacryrrhoea were noted in all animals on Day 1 and/or 2. In addition, one female and one male showed piloerection on Day 1. No skin effects were noted on the treated skin during the observation period.

Gross pathology:

One female showed smaller spleen compared to normal. No further abnormalities were found at macroscopic post mortem examination of the animals.

Other findings:

none

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The dermal LD50 value of Sodium N-(2-carboxyethyl)-N-(2-ethylhexyl)-ß-alaninate in Wistar rats was established to exceed 2000 mg/kg body weight. Based on these results, Sodium N-(2-carboxyethyl)-N-(2-ethylhexyl)-ß-alaninate does not have to be classified and has no obligatory labelling requirement for acute dermal toxicity according to the:
- Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2011),
- Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures.