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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
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
Remarks:
(purity of the test material was not noted)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
other: OECD Guideline 402 (Acute Dermal Toxicity), 1981
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): monoethanolamine
- Analytical purity: no data

Test animals

Species:
rabbit
Strain:
New Zealand White
Sex:
male/female

Administration / exposure

Type of coverage:
occlusive
Vehicle:
unchanged (no vehicle)
Duration of exposure:
24 hours
Doses:
1.0, 2.0 or 4.0 mL/kg bw
No. of animals per sex per dose:
5 animals
Control animals:
no
Details on study design:
Groups of five animals per sex (2-3 kg) were subjected to 24 hours of contact with monoethanolamine (1.0, 2.0, or 4.0 mL/kg bw) which was retained under impervious sheeting on the clipped, intact skin of the trunk. As necessary for larger doses, gauze was wrapped around the trunk over the sample to prevent leakage. Vetrap Bandaging Tape was wrapped over the impervious sheeting and the animal was returned to its cage for the contact period. Doses were varied by adjusting the volume of the test material. After the contact period, excess fluid was removed to diminish ingestion. Observations for toxicity and skin reactions were made at one hour, 7 days, and 14 days after the contact period. Animal weights were recorded at 0 days (before dose), 7 days and 14 days (just prior to termination). LD50 values and the estimated LD50 slopes were calculated by the moving average method (Thompson, 1947; Weil, 1983) and are based on a 14-day observation period. At death or termination, each animal was subjected to a gross pathologic evaluation.

Results and discussion

Preliminary study:

The LD50 value for males was 2.46 mL/kg bw (2504 mg/kg bw) with a 95% confidence level of 1.79- 3.39 mL/kg bw (1822 - 3451 mg/kg bw) and a slope of 5.60. The LD50 value for females was 2.83 mL/kg bw (2881 mg/kg bw) with a 95% confidence level of 1.61 - 4.98 mL/kg bw (1639 - 5070 mg/kg bw) and a slope of 3.89.
Effect levelsopen allclose all
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
>= 2.46 - <= 2.83 mL/kg bw
Key result
Sex:
male
Dose descriptor:
LD50
Effect level:
2 504 mg/kg bw
95% CL:
> 1 822 - < 3 451
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
2 881 mg/kg bw
95% CL:
> 1 639 - < 5 070
Mortality:
The numbers of deaths at each dose were as follows:
Dose (ml/kg) Numbers of Animals Dead Time of Death
(M/F)
4.0 5,4 1-2 days
2.0 1,1 2, 13 days
1.0 0,0 N/A
Deaths occurred within two days, except for one female that died at 13 days.
Clinical signs:
MALES
4.00 ml/kg dosing group:
erythema, edema, necrosis, ecchymosis at 1day; prostration in 1 animal at 1 day.

2.00 ml/kg dosing group:
erythema, edema at 1 to 7 days or death; necrosis at 1 to 14 days or death; ecchymosis at 1 day, persisting on 1 to ulceration at 7 or 14 days; desquamation, alopecia on 1 at 14 days; scabs at 14 days; sluggishness at 1 day or at 7 days; emaciation of 1 at 7 days; recovery of 2 survivors after 2 days.

1.00 ml/kg dosing group:
erythema at 1 day; persisting on 1 through 7 days; edema at 1 to 7 days; ecchymosis on 1 at 1 day; necrosis at 1 to 14 days; scabs, ulceration at 7 to 14 days. No signs of systemic toxicity.

FEMALES
4.00 ml/kg dosing group:
erythema, edema, ecchymosis at 1 day to death; necrosis at 1 day to death, persisting on 1 through 14 days; scabs, ulcerations on 1 at 7 to 14 days; sluggishness at 1 day; recovery of 1 at 2 days.

2.00 ml/kg dosing group:
erythema, edema at 1 to 7 days; necrosis at 1 to 14 days; ecchymosis at 1 day; scabs at death or termination; ulceration at 7 to 14 days; sluggishness in 2 at 1 day; abdominal distension in 1 at death;
recovery of affected survivor at 2 days.

1.00 ml/kg dosing group:
erythema at 1 day; edema at 1 to 7 days; necrosis at 1 to 14 days; ecchymosis on 1 at 1 day; scabs, ulceration at 7 to 14 days; desquamation on 1 at 14 days; abdominal distension and emaciation (in 1), audible breathing in 1 at 14 days.
Body weight:
Nothing abnormal reported.
Gross pathology:
MALES
4.00 ml/kg dosing group:
lungs salmon-colored; trachea of 1 animal dark red; thymus of 1 animal mottled dark red; large intestines of 1 animal hemorrhaged.

2.00 ml/kg dosing group:
in deceased animal, lungs mottled salmon-colored and bright red; in survivors, lungs bright pink, salmon-colored or mottled bright pink to dark red.

1.00 ml/kg dosing group: lungs of 1 animal dark red.

FEMALES

4.00 ml/kg dosing group:
in deceased animals, lungs salmon-colored to dark red, with dark red foci; thymus of 1 dark red; intestines hemorrhaged; in survivor, nothing remarkable.

2.00 ml/kg dosing group:
in deceased animal, stomach, intestines liquid and gas-filled; small intestines hemorrhaged; in survivors, lungs salmon-colored to red; kidneys of 1 with a pitted surface; intestines of 1 gas-filled.

1.00 ml/kg dosing group:
lungs salmon-colored to dark red, 1animal with dark red foci; stomachs and intestines of 2 animals liquid and/or gasfilled; small intestines of 1 animal hemorrhaged; abdominal cavity of 1 animal liquidfilled.

Applicant's summary and conclusion

Interpretation of results:
Category 5 based on GHS criteria
Conclusions:
The acute dermal (LD50) of 2 -aminoethanol was determined to be in range of 2.46 - 2.83 mL/kg bw in New Zealand White rabbits when applied on the intact skin. LD50 value of 2504 (95% CL: 1822- 3451) mg/kg bw and 2881 (95% CL: 1639 - 5070) mg/kg bw for males and females New Zealand White rabbits, respectively was also determined in this study the test material is therefore classified as Category 5 based on GHS criteria.
Executive summary:

The objective of the study was to determine the acute dermal toxicity of 2-aminoethanol when applied once to the intact rabbit skin.

New Zealand White rabbits weighing between 2 - 3 kg were used in this study. The test material was applied at following three doses (five animals/sex/dose) by adjusting its volume: 1.0, 2.0, or 4.0 mL/ kg bw.

Rabbits were subjected to 24 hours of contact to 2 -aminoethanol retained under impervious sheeting on the clipped and intact skin of the trunk. Vetrap Bandaging Tape was wrapped over the impervious sheeting and the animal was returned to its cage for the contact period. Gauge was also wrapped around the trunk over sample to prevent leakage in case of larger doses. After the contact period, excess fluid was removed to diminish ingestion.

Post treatment, all animals were observed for mortality, clinical signs, skin reactions and body weight changes for 14 days. After 14 days of observation, all surviving animals were euthanized, subjected to necropsy and examined for gross pathological changes.

No mortality was observed at 1.0 mL/kg bw dose. One male within two days and one female at day 13 died at 2.0 mL/kg bw dose while five males and four females died at 4.0 mL/kg bw within two days.

Erythema, edema, necrosis scabs and ulceration were observed in treated animals at 1.0, 2.0, or 4.0 mL/kg bw doses. Apart from these effects, at 1.0 mL/kg bw desquamation was observed in both sexes while abdominal distension, emaciation and audible breathing were also observed in female animals.Animals treated with 2.0 mL/kg bw showed sluggishness (both sexes) along with emaciation (male) and abdominal distention (female). Recovery was observed in survivors at this dose after two days. In high dose group (4.0 mL/kg bw), prostation was obseved in single male along with sluggishness in single female at day 1. One female rabbit also showed recovery after 2 days at high dose.

No abnormal changes in body weight were reported.

In all treated animals, changes in color and texture were observed in multiple internal organs of all animals at all doses. Instances of intestinal hemorrhage were observed in both sexes at high dose and a single instance was also reported in a female at low dose. At high dose, nothing remarkable was observed in the female animals.

Based on the above, the acute dermal (LD50) of 2 -aminoethanol was determined to be in range of 2.46- 2.83 mL/kg bw in New Zealand White rabbits when applined on the intact skin. LD50 value of 2504 (95% CL: 1822 - 3451) mg/kg bw and 2881 (95% CL: 1639 - 5070) mg/kg bw for males and females New Zealand White rabbits, respectively was also determined in this study.

The test material is therefore classified as Category 5 based on GHS criteria.