2-ethylhexyl mercaptoacetate

Endpoint summary

Description of key information

Acute toxicity studies have been conducted with EHTG by the dermal, inhalation and oral routes of exposure.  The acute oral toxicity value indicate moderate toxicity, with LD50 value in rats of 303 – 334 mg/kg bw. Acute dermal and inhalation toxicity is low, with an inhalation LC0 value in rats higher than 0.51 mg/L and dermal LD50 value in rats greater than 2000 mg/kg bw.

 

Oral

In an acute oral rat toxicity study with EHTG in peanut oil, the LD50 was 303 mg/kg bw (males) and 334 mg/kg bw (females) (Schmidt et al, 1974). There were 70 animals assigned to this study. There were no adverse effects seen in any of the rats during the macroscopic examination at necropsy and body weights were not adversely affected. A single sublethal doses of 80 mg EHTG/kg bw produced no significant damage of the liver or kidneys in either sex.

In an acute oral mouse toxicity study conducted under the same regimen as for rats (Schmidt et al, 1974), the LD50 for EHTG was 1430 (females) to 1710 (males) mg/kg bw. There were 70 animals assigned to this study.

In an acute oral rabbit toxicity study conducted under the same regimen as for rats (Schmidt et al, 1974), the LD50 for EHTG was 534 mg/kg bw (males). There were 8 animals assigned to this study.

In an acute oral guinea pig toxicity study conducted under the same regimen as for rats (Schmidt et al, 1974), the LD50 for EHTG was 955 (males) -1120 mg/kg bw (females). There were 66 animals assigned to this study.

 

Inhalation

In a 6 hr-inhalation study with EHTG, no mortality was observed in a rats, mice or guinea pigs exposed to 0.51 mg/L. At the end of the observation period, the body weights were normal and the necropsy did not reveal any substance related adverse effects (Schmidt et al, 1974).

Dermal

Undiluted EHTG was applied to the skin of ten Sprague-Dawley male and female rats at a dose of 2000 mg/kg (Clouzeau, 1993) following OECD test guideline 402. The test site was then covered by a semi-occlusive dressing for 24 hours. Clinical signs, mortality and body weight gain were checked for a period of 14 days and all animals were subjected to necropsy. Death occurred in 20% of the animals. No skin reactions were observed. On day 2 following exposure a marked decrease in spontaneous activity was noted in 4 animals. On day 5, there was a decrease in the body weight in a few animals. Thereafter, clinical signs and body weight gain were not affected by treatment. A macroscopic examination revealed no abnormalities. The LD50 for EHTG was greater than 2000 mg/kg bw.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national standard methods with acceptable restrictions No data on test design. Limited data on environmental conditions. No data on tested concentrations.

Qualifier:

no guideline available

Principles of method if other than guideline:

Standard acute method with one single administration by gavage per animal and per dose level.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: conventional random strain from "Staatlichen Zentralstelle für Versuchstierzucht und -versorgung, Berlin, Lichtenberg."
- Age at study initiation: no data
- Weight at study initiation: between 150 and 180 g
- Fasting period before study: 18 h before study
- Housing:groups of 10 rats
- Diet (e.g. ad libitum): pellets of standard food of K type
- Water (e.g. ad libitum): ad libitum
- Acclimation period: no data

Route of administration:

oral: gavage

Vehicle:

peanut oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 1/10 (v/v)

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: litterature data

Doses:

No data

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: every week
- Necropsy of survivors performed: yes
- Other examinations performed: body weight increase, necropsy

Statistics:

Calculation of LD50: Lichtfield and Wilcoxon for the days of application, and Deichmann and Leblanc until the end of deaths due to test substance.

Preliminary study:

No preliminary study

Sex:

male

Dose descriptor:

LD50

Effect level:

303 mg/kg bw

95% CL:

259 - 355

Sex:

female

Dose descriptor:

LD50

Effect level:

334 mg/kg bw

95% CL:

250 - 446

Mortality:

No details available

Clinical signs:

other: No data.

Gross pathology:

At necropsy there were no pathological section findings.

Other findings:

Additionnal single sublethal doses were tested: 80 mg/kg bw.
At this dose, after 20 hours, no significant damages of the liver or kidneys were observed (relative and absolute organ weight of liver and kidneys, Hexobarbital sleeping time, serum creatinine rate, activity of Serum LAP and Serum aldolase, hemoglobine rate, urine volume, albumine rate in urine, macrosopic observation . At necropsy there were no pathological section findings and body weights were not adversely affected.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The resulting LD50 was 303 mg/kg for male and 334 mg/kg for female.

Executive summary:

In an acute oral rat toxicity studywith EHTG in peanut oil, the LD50 was 303 mg/kg bw (males) and 334 mg/kg bw (females). There were 70 animals assigned to this study. There were no adverse effects seen in any of the rats during the macroscopic examination at necropsy and body weights were not adversely affected. A single sublethal doses of 80 mg EHTG/kg bw produced no significant damage of the liver or kidneys in either sex. 

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

303 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national standard methods with acceptable restrictions No data on test design. No data on environmental conditions. No data on tested concentrations.

Qualifier:

no guideline available

Principles of method if other than guideline:

Standard acute method with one uninterrupted exposure by inhalation over a short period of time per dose level.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Staatlichen Zentral stelle für Versuchstierzucht und -versorgung, Berlin-Lichtenberg
- Weight at study initiation: 150 to 180 g
- Fasting period before study: no
- Housing: groups of 10
- Diet (e.g. ad libitum): standard food of K type
- Water (e.g. ad libitum): ad libitum



ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C
- Air changes (per hr): dynamic procedure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

no data

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

6 h

Concentrations:

No data.

No. of animals per sex per dose:

5

Control animals:

not specified

Details on study design:

14 days observation after exposure

Statistics:

No data

Sex:

male/female

Dose descriptor:

LC0

Effect level:

> 0.51 mg/L air

Exp. duration:

6 h

Mortality:

No mortality until 0.51 mg test substance/L air

Clinical signs:

other: No clinical signs of adverse effects.

Body weight:

Body weight increase was normal.

Gross pathology:

Necropsy at the end of test did not reveal any substance related adverse effects.

Interpretation of results:

GHS criteria not met

Conclusions:

The LC0 was determined to be higher than 0.51 mg/L (the only tested dose).

Executive summary:

Acute inhalation toxicity of 2-ethylhexyl mercaptoacetate was tested on male and female rats. There was no mortality until 0.51 mg test substance/L air. Animals bodyweight increased normally. Necropsy revealed no adverse effects.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating conc.

Value:

510 mg/m³ air

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 16 to 30 September 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Iffa Credo (France)
- Age at the beginning of treatment: approximately 8 weeks old
- Weight at the beginning of treatment: mean: 265 +/- 10 g for males, 220 +/- 10 g for females
- Fasting period before study: not reported
- Housing: 4 to 7 animals per sex and per polycarbonate cage (48 x 27 x 20 cm)
- Diet (e.g. ad libitum): A04 C pelleted diet ad libitum
- Water (e.g. ad libitum): filtered by a Millipore membrane, ad libitum
- Acclimation period: at least 5 days before the beginning of the study

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/-3
- Humidity (%): 50 +/- 20
- Air changes (per hr): 13
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: September 16, 1993 To: September 30, 1993

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 5 x 6 cm for females; 5 x 7 cm for males
- % coverage: 10%
- Type of wrap if used: restraining bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw (2.06 mL/kg)

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: clinical signs at least once daily, mortality at least twice daily, weighing before application and on days 5, 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: animals found dead and surviving animals sacrificed on day 15 were subject to macroscopic examination.

Statistics:

Not required (Limit test)

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

Two test animals were found dead. The first one (male) 4 hours after application and the second one (female) 24 hours after the application.

Clinical signs:

other: No cutaneous reactions were noted during the study. On day 2, sedation was observed in 4 animals. No other clinical signs were noted during the study.

Gross pathology:

No apparent abnormalities were observed.

Interpretation of results:

GHS criteria not met

Conclusions:

The dermal LD50 of the substance was found to be greater than 2000 mg/kg bw in rats.

Executive summary:

Undiluted EHTG was applied to the skin of ten Sprague-Dawley male and female rats at a dose of 2000 mg/kg following OECD test guideline 402. The test site was then covered by a semi-occlusive dressing for 24 hours. Clinical signs, mortality and body weight gain were checked for a period of 14 days and all animals were subjected to necropsy. Death occurred in 20% of the animals. No skin reactions were observed. On day 2 following exposure a marked decrease in spontaneous activity was noted in 4 animals. On day 5, there was a decrease in the body weight in a few animals. Thereafter, clinical signs and body weight gain were not affected by treatment. A macroscopic examination revealed no abnormalities. The LD50 for EHTG was greater than 2000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Justification for classification or non-classification

According to REGULATION (EC) No 1272/2008 of 16 December 2008 and the available acute toxicity data, 2 -ethylhexyl mercaptoacetate is classified:

- Acute oral toxicity: Toxic, category 4

- Acute inhalation toxicity : not classified

- Acute dermal toxicity : not classfied