3-mercaptopropane-1,2-diol

Endpoint summary

Description of key information

TG has an oral LD50 of 648 mg/kg bw. The percutaneous LD50 is 683 mg/bw.

The 4-h LC50, read-across from GMT, is 0.51 mg/L

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:

1975

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 401 (Acute Oral Toxicity)

GLP compliance:

no

Remarks:

study was conducted prior to the GLP legislation

Test type:

standard acute method

Limit test:

no

Specific details on test material used for the study:

Batch 297-1382

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

BW: 200-300 g

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Remarks:

except for 0.05 and 0.25 mg/kg dose, which were administered as 1% solution in water

Details on oral exposure:

animals were fasted for 24 h before dosing

Doses:

0.05, 0.25, 0.50, 1.00, 5.00 mL/kg bw
62, 312, 623, 1247, 6234 mg/kg bw (using density of 1.25 g/mL)

No. of animals per sex per dose:

5 (3m / 2f)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

Statistics:

Probit analysis (Miller & Tainter, Proc Soc Biol Med 57, 261 (1944))

Sex:

male/female

Dose descriptor:

LD50

Effect level:

0.52 mL/kg bw

Based on:

test mat.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

648 mg/kg bw

Based on:

test mat.

Mortality:

mg/kg bw dead total mortality
62 0 5 0%
312 0 5 0%
623 2 5 40%
1247 5 5 100%
6234 5 5 100%

Clinical signs:

other: not reported

Gross pathology:

not reported

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Based on an LD50 of 648 mg/kg bw, monothioglycerol should be classified as Acute Tox 4 - H302: Harmful if swallowed

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

648 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

see attached justifications

Reason / purpose for cross-reference:

read-across source

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

inhalation: aerosol

Duration of exposure:

1 h

Concentrations:

2.04 mg/L nominal concentration

No. of animals per sex per dose:

5

Control animals:

no

Sex:

male/female

Dose descriptor:

LC0

Effect level:

>= 2.04 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

1 h

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.04 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

1 h

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 0.51 mg/L air

Based on:

other: extrapolation using Haber's Law

Exp. duration:

4 h

Mortality:

none

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The extrapolated 4-h LC50 of GMT is greater than 0.51 mg/L, but it is assumed that the 4-h LC50 for monothioglycerol could be below 1 mg/L.
Thus, monothioglycerol should be classified as Acute Tox 3 - H331: Toxic if inhaled

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: 16 CCFR 1500.40

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

no

Remarks:

study was conducted prior to the GLP legislation

Test type:

standard acute method

Limit test:

no

Specific details on test material used for the study:

Batch 297-1382

Species:

rabbit

Strain:

other: Albino, not further specified

Sex:

not specified

Type of coverage:

not specified

Vehicle:

not specified

Duration of exposure:

not reported

Doses:

0.2, 0.50, 0.75, 1.00, 2.00 mL/kg bw
249, 623, 935, 1247, 2494 mg/kg bw (using density of 1.25 g/mL)

No. of animals per sex per dose:

5

Control animals:

not required

Key result

Sex:

not specified

Dose descriptor:

LD50

Effect level:

0.54 mL/kg bw

Based on:

test mat.

Key result

Sex:

not specified

Dose descriptor:

LD50

Effect level:

673 mg/kg bw

Based on:

test mat.

Mortality:

mg/kg bw Dead total Mortality
249 0 5 0%
623 2 5 40%
935 4 5 80%
1247 5 5 100%
2494 5 5 100%

Clinical signs:

other: not reported

Gross pathology:

not reported

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

Based on an LD50 of 673 mg/kg bw, monothioglycerol should be classified as Acute Tox 3 - H311: Toxic in contact with skin.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

673 mg/kg bw

Justification for classification or non-classification

Based on an LD50 of 648 mg/kg bw, monothioglycerol should be classified as Acute Tox 4 - H302: Harmful if swallowed

The extrapolated 4-h LC50 read-across from GMT is greater than 0.51 mg/L, but it is assumed that the 4-h LC50 for monothioglycerol could be below 1 mg/L. Thus, monothioglycerol should be classified as Acute Tox 3 - H331: Toxic if inhaled