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Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
0.364 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
Oral
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
100
Modified dose descriptor starting point:
NOAEL
Value:
36.4 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:
It is assumed that oral and dermal absorption rates are equal.
AF for differences in duration of exposure:
2
Justification:
DNEL is based on an oral 90 day study
AF for interspecies differences (allometric scaling):
4
Justification:
experimental animal was rat
AF for other interspecies differences:
2.5
AF for intraspecies differences:
5
Justification:
workers
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
acute toxicity
Route of original study:
Dermal
DNEL related information
Modified dose descriptor starting point:
NOAEL

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
skin irritation/corrosion
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
skin irritation/corrosion

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - workers

No subchronic studies are available for GMT. The first step in GMT metabolism is the hydrolysis of its ester bonds resulting in glycerol and mercaptoacetate. Long-term exposure, dermal, systemic effect DNEL was therefore based on a subchronic oral toxicity study performed in rats with the toxicological most relevant metabolite mercaptoacetate (sodium salt, NaTG). In this study a subchronic oral NOAEL of 20 mg/kg bw /day was found. This refers to an equimolar NAEL of 36.4 mg/kg bw/day based on the molecular weight ratio and the level of esterification.

Calculation of NAEL: NAEL= (NOAEL x MW GMT/ MW NaTG)/ level of esterification

MW GMT: 166.2 g/mol

MW NaTG: 114.1 g/mol

Level of esterification of glycerol with mercaptoacetic acid: 80%

Judging from the ratio of oral to dermal LD50 values (177vs 2000 mg/kg bw), the dermal absorption of GMT is predicted to be low, therefore a factor of 0.1 was added for dermal absorption.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
0.182 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
Oral
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
200
Modified dose descriptor starting point:
NOAEL
Value:
36.4 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:
It is assumed that oral and dermal absorption rates are equal.
AF for differences in duration of exposure:
2
Justification:
based on an oral 90 day study
AF for interspecies differences (allometric scaling):
4
Justification:
experimental animal was rat
AF for other interspecies differences:
2.5
AF for intraspecies differences:
10
Justification:
for general population
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
acute toxicity
Route of original study:
Dermal
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
skin irritation/corrosion
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
skin irritation/corrosion

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
182 µg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
Oral
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
200
Modified dose descriptor starting point:
NOAEL
Value:
36.4 mg/kg bw/day
AF for differences in duration of exposure:
2
Justification:
based on an oral 90 day study
AF for interspecies differences (allometric scaling):
4
Justification:
experimental animal was rat
AF for other interspecies differences:
2.5
AF for intraspecies differences:
10
Justification:
for general population
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
acute toxicity
Route of original study:
Oral
DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - General Population

No subchronic studies are available for GMT. The first step in GMT metabolism is the hydrolysis of its ester bonds resulting in glycerol and mercaptoacetate. Long-term exposure, dermal, systemic effect DNEL was therefore based on a subchronic oral toxicity study performed in rats with the toxicological most relevant metabolite mercaptoacetate (as NaTG).

In this study a subchronic oral NOAEL of 20 mg/kg bw /day was found. This refers to an equimolar NAEL of 36.4 mg/kg bw/day based on the molecular weight ratio and the level of esterification.

Calculation of NAEL: NAEL= (NOAEL x MW GMT/ MW NaTG)/ level of esterification

MW GMT: 166.2 g/mol

MW NaTG: 114.1 g/mol

Level of esterification of glycerol with mercaptoacetic acid: 80%

Judging from the ratio of oral to dermal LD50 values (177 vs 2000 mg/kg bw), the dermal absorption of GMT is predicted to be low, therefore a factor of 0.1 was added for dermal absorption.