Registration Dossier

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
2.13 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
DNEL value:
181 mg/kg bw/day
Modified dose descriptor starting point:
NOAEC
DNEL value:
159.57 mg/m³
Explanation for the modification of the dose descriptor starting point:

Regarding absorption, in the absence of reliable data for both the starting route (oral) and the end route (inhalation), worst case assumptions were made. It was assumed that a limited absorption occurs by the oral route, leading to a low (conservative) internal NOAEL. To secure a conservative external NOAEL, a maximum absorption should be assumed for the inhalation route (i.e.; 100%) leading to a low external NOAEL. Thus, in the case of oral-to- inhalation extrapolation, it is proposed to include a default factor of 2, i.e. the absorption percentage by oral route is half that of the inhalation absorption as suggested in ECHA Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.8 (2012).

To convert the oral NOAEL into inhalatory NOAEC, a rat default respiratory volume was used corresponding to the daily duration of human exposure (sRVrat: 0.38 m3/kg bw/8 h). For workers a correction was added for the difference between respiratory rates under standard conditions (sRVhuman: 6.7 m3 for an 8-h exposure period) and under conditions of light activity (wRV: 10 m3 for an 8-h exposure period). Thus, the corrected dose descriptor for inhalation is [181 mg/kg bw/day] X  [1/0.38 m3/kg bw/day] X [2/1] X [6.7 m3/10m3]. Thus, the corrected dose descriptor for inhalation is 165.74 mg/m3 for workers.

AF for dose response relationship:
1
Justification:
The dose-descriptor is a NOAEL. Table R.8-6 ECHA REACH Guidance
AF for differences in duration of exposure:
6
Justification:
Default factor for a sub-acute study. Table R.8-5 ECHA REACH Guidance
AF for interspecies differences (allometric scaling):
1
Justification:
Table R.8-4 ECHA REACH Guidance. Assessment factor not to be used for inhalation route since the differences in the metabolic rate/bw has already been taken into account in the corrected dose descriptor.
AF for other interspecies differences:
2.5
Justification:
Default factor for other interspecies differences. Table R.8-6 ECHA REACH Guidance
AF for intraspecies differences:
5
Justification:
Default factor for worker. Table R.8-6 ECHA REACH Guidance
AF for the quality of the whole database:
1
Justification:
Default factor for good/standard quality of the database taken into account completeness of the standard information requirements for the tonnage band
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties
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:
0.603 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
DNEL value:
181 mg/kg bw/day
Modified dose descriptor starting point:
NOAEL
DNEL value:
181 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:

For potential dermal exposure, route-to-route extrapolation from the oral NOAEL value was considered appropriate. Since a maximal absorption already occurred by oral route, no additional factor was introduced.

AF for dose response relationship:
1
Justification:
The dose-descriptor is a NOAEL. Table R.8-6 ECHA REACH Guidance.
AF for differences in duration of exposure:
6
Justification:
Default factor for a sub-acute study. Table R.8-5 ECHA REACH Guidance.
AF for interspecies differences (allometric scaling):
4
Justification:
Default allometric scaling factor for rats. Table R.8-4 ECHA REACH Guidance.
AF for other interspecies differences:
2.5
Justification:
Default factor for other interspecies differences. Table R.8-6 ECHA REACH Guidance
AF for intraspecies differences:
5
Justification:
Default factor for worker. Table R.8-6 ECHA REACH Guidance
AF for the quality of the whole database:
1
Justification:
Default factor for good/standard quality of the database taken into account completeness of the standard information requirements for the tonnage band
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties
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

NOAEL (systemic toxicity) = 3,000 ppm diet (181 mg/kg bw/d); OECD 422; Anon. (2017)

Long-term systemic hazard assessment for this substance to workers is based on a sub-acute repeated dose toxicity study, combined with reproduction and developmental screening (OECD 422, Anon., 2017). During the treatment period, a dose-dependent decrease in overall mean body weight gain was apparent in all groups, with a greater extent seen in groups treated at 7500 ppm, of toxicity and recovery phase males and females exposed to the test item when compared to controls; this decrease in overall weight gain was largely attributable to lower body weight gain and body weight losses during Week 1. This coincides with the reduced food intake seen in the first few days of treatment. A similar trend in body weight performance was evident among the reproductive phase females in the gestation and lactation period and was considered to be an adverse effect.  Within the scope of this study it was not possible to establish with certainly the aetiology of the potentially adverse reduction in birth weight and subsequent body weight gain of the male offspring in the 3000 and 7500 ppm group and female offspring in the 7500 ppm group.  This may have been as a result of the parent females being smaller and consuming less food (thus there being reduced levels of nutrients available to pass to the fetus in utero and reduced quality milk in lactation), or a direct effect ofthe test item by cross‑placental in utero exposure. The reduction in body weight gain of the offspring derived from parent animals given 7500 ppm was considered adverse.

The lowest NOAEL (3,000 ppm diet, equivalent to 181 mg/kg bw/d) was therefore used to derive the worker DNELs in accordance with ECHA Guidance.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
0.525 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
DNEL value:
181 mg/kg bw/day
Modified dose descriptor starting point:
NOAEC
DNEL value:
78.7 mg/m³
Explanation for the modification of the dose descriptor starting point:

Regarding absorption, in the absence of reliable data for both the starting route (oral) and the end route (inhalation), worst case assumptions were made. It was assumed that a limited absorption occurs by the oral route, leading to a low (conservative) internal NOAEL. To secure a conservative external NOAEL, a maximum absorption should be assumed for the inhalation route (i.e.; 100%) leading to a low external NOAEL. Thus, in the case of oral-to- inhalation extrapolation, it is proposed to include a default factor of 2, i.e. the absorption percentage by oral route is half that of the inhalation absorption as suggested in ECHA Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.8 (2012). To convert the oral NOAEL into inhalatory NOAEC, a rat default respiratory volume was used corresponding to the daily duration of human exposure (sRVrat: 1.15 m3/kg bw/24 h). Thus, the corrected dose descriptor for inhalation is [181 mg/kg bw/day] x [1/1.15 m3/kg bw/ day] x [2/1]. Thus, the corrected dose descriptor for inhalation is 78.70 mg/m3 for the general population.

AF for dose response relationship:
1
Justification:
The dose-descriptor is a NOAEL. Table R.8-6 ECHA REACH Guidance.
AF for differences in duration of exposure:
6
Justification:
Default factor for a sub-acute. Table R.8-5 ECHA REACH Guidance.
AF for interspecies differences (allometric scaling):
1
Justification:
Table R.8-4 ECHA REACH Guidance. Assessment factor not to be used for inhalation route since the differences in metabolic rate/bw has already been taken into account for the corrected dose descriptor.
AF for other interspecies differences:
2.5
Justification:
Default factor for other interspecies differences. Table R.8-6 ECHA REACH Guidance
AF for intraspecies differences:
10
Justification:
Default factor for general population. Table R.8-6 ECHA REACH Guidance
AF for the quality of the whole database:
1
Justification:
Default factor for good/standard quality of the database taken into account completeness of the standard information requirements for the tonnage band.
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties
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:
0.302 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
DNEL value:
181 mg/kg bw/day
Modified dose descriptor starting point:
NOAEL
DNEL value:
181 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:

For potential dermal exposure, route-to-route extrapolation from the oral NOAEL value was considered appropriate. Since a maximal absorption already occurred by oral route, no additional factor was introduced.

AF for dose response relationship:
1
Justification:
The dose-descriptor is a NOAEL. Table R.8-6 ECHA REACH Guidance.
AF for differences in duration of exposure:
6
Justification:
Default factor for a sub-acute study. Table R.8-5 ECHA REACH Guidance.
AF for interspecies differences (allometric scaling):
4
Justification:
Default allometric scaling factor for rats. Table R.8-4 ECHA REACH Guidance.
AF for other interspecies differences:
2.5
Justification:
Default factor for other interspecies differences. Table R.8-6 ECHA REACH Guidance.
AF for intraspecies differences:
10
Justification:
Default factor for general population. Table R.8-6 ECHA REACH Guidance
AF for the quality of the whole database:
1
Justification:
Default factor for good/standard quality of the database taken into account completeness of the standard information requirements for the tonnage band
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties
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:
0.603 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
DNEL value:
181 mg/kg bw/day
Modified dose descriptor starting point:
NOAEL
DNEL value:
181 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:

No modification of the dose descriptor starting point is required. The endpoint used to derive the DNEL uses the oral route for exposure.

AF for dose response relationship:
1
Justification:
The dose-descriptor is a NOAEL. Table R.8-6 ECHA REACH Guidance.
AF for differences in duration of exposure:
6
Justification:
Default factor for a sub-acute study. Table R.8-5 ECHA REACH Guidance.
AF for interspecies differences (allometric scaling):
4
Justification:
Default allometric scaling factor for rats. Table R.8-4 ECHA REACH Guidance.
AF for other interspecies differences:
2.5
Justification:
Default factor for other interspecies differences. Table R.8-6 ECHA REACH Guidance.
AF for intraspecies differences:
10
Justification:
Default factor for good/standard quality of the database taken into account completeness, consistency and the standard information requirements for the tonnage band.
AF for the quality of the whole database:
1
Justification:
Default factor for good/standard quality of the database taken into account completeness of the standard information requirements for the tonnage band
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties.
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

NOAEL (systemic toxicity) = 3,000 ppm diet (181 mg/kg bw/d); OECD 422; Anon. (2017)

Long-term systemic hazard assessment for this substance to the general population is based on a sub-acute repeated dose toxicity study, combined with reproduction and developmental screening (OECD 422, Anon., 2017). During the treatment period, a dose-dependent decrease in overall mean body weight gain was apparent in all groups, with a greater extent seen in groups treated at 7500 ppm, of toxicity and recovery phase males and females exposed to the test item when compared to controls; this decrease in overall weight gain was largely attributable to lower body weight gain and body weight losses during Week 1. This coincides with the reduced food intake seen in the first few days of treatment. A similar trend in body weight performance was evident among the reproductive phase females in the gestation and lactation period and was considered to be an adverse effect.  Within the scope of this study it was not possible to establish with certainly the aetiology of the potentially adverse reduction in birth weight and subsequent body weight gain of the male offspring in the 3000 and 7500 ppm group and female offspring in the 7500 ppm group.  This may have been as a result of the parent females being smaller and consuming less food (thus there being reduced levels of nutrients available to pass to the fetus in utero and reduced quality milk in lactation), or a direct effect ofthe test item by cross‑placental in utero exposure. The reduction in body weight gain of the offspring derived from parent animals given 7500 ppm was considered adverse.

The lowest NOAEL (3,000 ppm diet, equivalent to 181 mg/kg bw/d) was therefore used to derive the general population DNELs in accordance with ECHA Guidance.