Registration Dossier

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
11.75 mg/m³
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
Oral
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
75
Dose descriptor starting point:
NOAEL
Value:
1 000 mg/kg bw/day
Modified dose descriptor starting point:
NOAEC
Value:
881.6 mg/m³
Explanation for the modification of the dose descriptor starting point:

Due to lack of repeated dose toxicity data by the inhalation route, a route to route extrapolation was performed. The NOAEL (oral) is converted into a NOAEC (corrected) in accordance to guidance on information requirements and chemical safety assessment, Chapter R.8, ECHA, May 2008. The NOAEL (oral) has to be divided by a factor of 0.38 m3/kg body weight and corrected for activity driven differences of respiratory volumes in workers compared to workers in rest (6.7 m3/10 m3). In addition, a default factor of 2 is applied to account for differences in oral and inhalative absorption properties. The corrected starting point is therefore:

NOAEC (corrected) = 1000 mg/kg / 0.38 m3/kg x 0.5 x (6.7 m3/10m3) = 881.6 mg/m3

AF for dose response relationship:
1
Justification:
The dose response relationship is considered unremarkable, therefore no additional factor is used.
AF for differences in duration of exposure:
6
Justification:
extrapolation from subacute to chronic
AF for interspecies differences (allometric scaling):
1
Justification:
Allometric scaling is part of the route to route extrapolation
AF for other interspecies differences:
2.5
Justification:
standard factor for remaining uncertainties
AF for intraspecies differences:
5
Justification:
standard factor for worker
AF for the quality of the whole database:
1
Justification:
GLP and guideline compliant study
AF for remaining uncertainties:
1
Justification:
The approach used for DNEL derivation is conservative. No further assessment factors are required.
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:
33.3 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):
300
Dose descriptor starting point:
NOAEL
Value:
1 000 mg/kg bw/day
Modified dose descriptor starting point:
NOAEL
Value:
10 000 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:

The dermal route is typically covered by oral route information in the absence of data for this administration route. According to ECHA guidance on toxicokinetics, there are no exclusion criteria for skin permeability, but a molecular weight of > 500 Da and a log Pow of > 4 are given as indicators for low absorption (10% or less). Considering the molecular weight of 721 Da and a calculated log Pow >19, these criteria are by far fulfilled. Furthermore, in an acute dermal toxicity study only nonspecific signs of treatment, i. e. dermal absorption were observed up to the highest dose of 2000 mg/kg bw. Therefore, the NOAEL is adjusted with a dermal penetration factor of 0.1, resulting in a modified NOAEL of 1000*0.1=10000 mg/kg body weight.

AF for dose response relationship:
1
Justification:
The dose response relationship is considered unremarkable, therefore no additional factor is used.
AF for differences in duration of exposure:
6
Justification:
extrapolation from subacute to chronic
AF for interspecies differences (allometric scaling):
4
Justification:
extrapolation from rat to human
AF for other interspecies differences:
2.5
Justification:
standard factor for remaining uncertainties
AF for intraspecies differences:
5
Justification:
standard factor for worker
AF for the quality of the whole database:
1
Justification:
GLP-compliant guideline study
AF for remaining uncertainties:
1
Justification:
The approach used for DNEL derivation is conservative. No further assessment factors are required.
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

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - workers

Identification of relevant dose descriptor

The NOAEL of 1000 mg/kg body weight observed in the subacute oral repeated dose toxicity study with rats was identifies as the most relevant value and was chosen for derivation of the DNEL.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
2.89 mg/m³
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
Oral
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
150
Dose descriptor starting point:
NOAEL
Value:
1 000 mg/kg bw/day
Modified dose descriptor starting point:
NOAEC
Value:
434 mg/m³
Explanation for the modification of the dose descriptor starting point:

Because no inhalation study is available, a route to route extrapolation was performed. The NOAEL (oral) has to be modified into a NOAEC (corrected) in accordance to guidance on information requirements and chemical safety assessment, Chapter R.8, ECHA, May 2008. Here, the NOAEL has to be divided by a factor of 1.15 m3/kg body weight. In addition, a default factor of 2 is applied to account for differences in oral and inhalative absorption properties. The corrected starting point is therefore:

NOAEC (corrected) = 1000 mg/kg / 1.15 m3/kg x 0.5 = 434 mg/m3

AF for dose response relationship:
1
Justification:
The dose response relationship is considered unremarkable, therefore no additional factor is used.
AF for differences in duration of exposure:
6
Justification:
extrapolation from subacute to chronic
AF for interspecies differences (allometric scaling):
1
Justification:
Allometric scaling is part of the route to route extrapolation
AF for other interspecies differences:
2.5
Justification:
standard factor for remaining uncertainties
AF for intraspecies differences:
10
Justification:
standard factor for the general population
AF for the quality of the whole database:
1
Justification:
GLP and guideline compliant study
AF for remaining uncertainties:
1
Justification:
The approach used for DNEL derivation is conservative. No further assessment factors are required.
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:
16.67 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):
600
Dose descriptor starting point:
NOAEL
Value:
1 000 mg/kg bw/day
Modified dose descriptor starting point:
NOAEL
Value:
10 000 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:

The dermal route is typically covered by oral route information in the absence of data for this administration route. According to ECHA guidance on toxicokinetics, there are no exclusion criteria for skin permeability, but a molecular weight of > 500 Da and a log Pow of > 4 are given as indicators for low absorption (10% or less). Considering the molecular weight of 721 Da and a calculated log Pow >19, these criteria are by far fulfilled. Furthermore, in an acute dermal toxicity study only nonspecific signs of treatment, i. e. dermal absorption were observed up to the highest dose of 2000 mg/kg bw. Therefore, the NOAEL is adjusted with a dermal penetration factor of 0.1, resulting in a modified NOAEL of 1000*0.1=10000 mg/kg body weight.

AF for dose response relationship:
1
Justification:
The dose response relationship is considered unremarkable, therefore no additional factor is used.
AF for differences in duration of exposure:
6
Justification:
extrapolation from subacute to chronic
AF for interspecies differences (allometric scaling):
4
Justification:
extrapolation from rat to humans
AF for other interspecies differences:
2.5
Justification:
standard factor for remaining uncertainties
AF for intraspecies differences:
10
Justification:
standard factor for the general population
AF for the quality of the whole database:
1
Justification:
GLP-compliant guideline study
AF for remaining uncertainties:
1
Justification:
The approach used for DNEL derivation is conservative. No further assessment factors are required.
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

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
1.67 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):
600
Dose descriptor starting point:
NOAEL
Value:
1 000 mg/kg bw/day
AF for dose response relationship:
1
Justification:
The dose response relationship is considered unremarkable, therefore no additional factor is used.
AF for differences in duration of exposure:
6
Justification:
extrapolation from subacute to chronic
AF for interspecies differences (allometric scaling):
4
Justification:
extrapolation from rat to human
AF for other interspecies differences:
2.5
Justification:
standard factor for remaining uncertainties
AF for intraspecies differences:
10
Justification:
standard factor for the general population
AF for the quality of the whole database:
1
Justification:
GLP-compliant guideline study
AF for remaining uncertainties:
1
Justification:
The approach used for DNEL derivation is conservative. No further assessment factors are required.
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - General Population

The dose descriptor chosen is the same as for workers (see above). The NOAEL of 1000 mg/kg observed in the subacute oral repeated dose toxicity study in rats was used as starting point to derive the DNELs.