Diquat dibromide

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.011 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):

25

Dose descriptor starting point:

NOAEL

Value:

0.934 mg/kg bw/day

Modified dose descriptor starting point:

NOAEC

Value:

0.27 mg/m³

Explanation for the modification of the dose descriptor starting point:

The substance fulfils the REACH Annex VII to Annex XI information requirements in accordance with ECHA guidance R7.5-7.7 (2017) for assessing long-term systemic toxicity. Since no repeated dose inhalation study is available, route-to-route extrapolation from the oral exposure route is performed. The starting point is the NOAEL from the 1-year dietary study in dogs; 0.934 mg/kg bw/day. This oral dog NOAEL is converted to an inhalation NOAEC for dogs by using a default respiratory volume for the dog corresponding to 8 hours (0.13 m3/kg bw). The values of 4 % oral absorption (based on toxicokinetics) and 100% absorption upon inhalation (worst case standard value) have been used. The resulting dog inhalation NOAEC is converted into inhalation worker NOAEC by correction for respiratory rate based on activity (6.7 m3 for normal light activity versus 10 m3 for worker activity) and by correction for 5 day exposure (7 days exposure per week in the study versus 5 days per week for workers): 0.934 * (1/0.13) * (4/100)* (6.7/10) * (7/5) = 0.27 mg/m3.

AF for dose response relationship:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, for the dose-response relationship, consideration should be given to the uncertainties in the dose descriptor (NOAEL, benchmark dose,…) as the surrogate for the true no-adverse-effect-level (NAEL). In this case the starting point for the DNEL calculation is a NOAEL, derived from a study which is of good quality and without uncertainties. Therefore the default assessment factor is 1.

AF for differences in duration of exposure:

2

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, a factor allowing for differences in the experimental exposure duration and the duration of exposure for the worker and scenario under consideration needs to be considered taking into account that a) in general the experimental NOAEL will decrease with increasing exposure times and b) other and more serious adverse effects may appear with increasing exposure times. Consequently, to end up with the most conservative DNEL for repeated dose toxicity, chronic exposure is the ‘worst case’. For a sub-chronic toxicity study, an assessment factor of 2 is to be applied.

AF for interspecies differences (allometric scaling):

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, as long as route-to-route extrapolation is not needed, allometric scaling should not be applied in cases where the dose unit (original or transformed) in experimental animal studies are expressed as concentrations (e.g. in mg/m³ air, ppm in diet, or mg/L in the drinking water) as these are assumed to be already scaled according to the allometric principle, since ventilation rate and food intake directly depend on the basal metabolic rate. In this case, route-to-route extrapolation is performed from an oral feeding study. The derived NOAEL is modified according to allometric principles to a NOAEC (mg/m³), therefore additional assessment factor for allometric scaling is not needed.

AF for other interspecies differences:

2.5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, interspecies differences result from variation in the sensitivity of species due to differences in toxicokinetics and toxicodynamics. Some of the toxicokinetic differences can be explained by differences in body size (and related differences in basal metabolic rate). As no substance-specific data are available, the standard procedure for threshold effects is followed. As a default, an additional factor of 2.5 for interspecies differences (other than allometric scaling), i.e. toxicokinetic differences not related to metabolic rate (small part) and toxicodynamic differences (larger part) is applied.

AF for intraspecies differences:

5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, intraspecies differences in human result from a multitude of biological factors such as genetic polymorphism affecting e.g. toxicokinetics/metabolism, age, gender, health status and nutritional status. For workers, as standard procedure for threshold effects a default assessment factor of 5 is to be used, based on the fact that this sub population does not cover the very young, the very old, and the very ill.

AF for the quality of the whole database:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, the evaluation of the total toxicological database should include an assessment whether the available information as a whole meets the tonnage driven data requirements necessary to fulfil the REACH requirements, or whether there are data gaps (completeness of the database). Furthermore, the hazard data should be assessed for the reliability and consistency across different studies and endpoints and taking into account the quality of the testing method, size and power of the study design, biological plausibility, dose-response relationships and statistical association (adequacy of the database). When taking into account the standard information requirements and the completeness and consistency of the database the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

AF for remaining uncertainties:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, there are no remaining uncertainties. Since there are no further uncertainties, the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

Acute/short term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.26 mg/m³

Most sensitive endpoint:

acute toxicity

Route of original study:

By inhalation

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

1 250

Dose descriptor starting point:

other: LC50

Value:

2.26 mg/m³

Modified dose descriptor starting point:

other: LC50

Value:

321.52 mg/m³

Explanation for the modification of the dose descriptor starting point:

The substance fulfils the REACH Annex VII to Annex XI information requirements in accordance with ECHA guidance R7.5-7.7 (2017) for assessing long-term systemic toxicity. The starting point is the rat inhalation LC50. The LC50 is converted into inhalation worker NOAEC by correction for respiratory rate for 15 minutes based on activity (0.21 m3 for normal light activity versus 0.31 m3 for worker activity), by using a default respiratory volume for the rat corresponding to 15 minutes (0.012 m3/kg bw) and by correction for 15 minutes peak exposure (4 hours exposure in the study versus 15 minutes for workers). The correction for the duration of exposure is done according to Haber’s law. The Haber’s law constant states that the concentration times the time is a constant. Cⁿ₁x t₁= Cⁿ₂x t₂(for which n=3, since extrapolation to shorter duration), thus (2.26)³x 4 = C³x 0.25, and C = 3 = 5.70 mg/m³. Next, the value is corrected for worker activity and the default respiratory volume: 5.70 * (1/0.012) * (0.21/0.31) = 321.52 mg/m3

AF for dose response relationship:

100

Justification:

An inhalatory DNEL acute is derived by applying a large assessment factor for severity of effect to the (time-scaled, if needed) LC50-value. There is no scientific basis for a default value of this assessment factor (for the extrapolation of a lethal concentration into a NOAEC). Still, a default AF of 100 is suggested as a starting point, but the factor can be modified in light of the whole toxicity database for that substance provided that a sound justification is given. The starting point is the LC50 from acute inhalation study in rats; 0.1 mg/L which translates to 100 mg/m3. An assessment factor of 100 for severity of effect to the LC50 value is applied.

AF for interspecies differences (allometric scaling):

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, as long as route-to-route extrapolation is not needed, allometric scaling should not be applied in cases where the dose unit (original or transformed) in experimental animal studies are expressed as concentrations (e.g. in mg/m³ air, ppm in diet, or mg/L in the drinking water) as these are assumed to be already scaled according to the allometric principle, since ventilation rate and food intake directly depend on the basal metabolic rate. In this case, route-to-route extrapolation is performed from an oral feeding study. The derived NOAEL is modified according to allometric principles to a NOAEC (mg/m³), therefore additional assessment factor for allometric scaling is not needed.

AF for other interspecies differences:

2.5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, interspecies differences result from variation in the sensitivity of species due to differences in toxicokinetics and toxicodynamics. Some of the toxicokinetic differences can be explained by differences in body size (and related differences in basal metabolic rate). As no substance-specific data are available, the standard procedure for threshold effects is followed. As a default, an additional factor of 2.5 for interspecies differences (other than allometric scaling), i.e. toxicokinetic differences not related to metabolic rate (small part) and toxicodynamic differences (larger part) is applied.

AF for intraspecies differences:

5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, intraspecies differences in human result from a multitude of biological factors such as genetic polymorphism affecting e.g. toxicokinetics/metabolism, age, gender, health status and nutritional status. For workers, as standard procedure for threshold effects a default assessment factor of 5 is to be used, based on the fact that this sub population does not cover the very young, the very old, and the very ill.

AF for the quality of the whole database:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, the evaluation of the total toxicological database should include an assessment whether the available information as a whole meets the tonnage driven data requirements necessary to fulfil the REACH requirements, or whether there are data gaps (completeness of the database). Furthermore, the hazard data should be assessed for the reliability and consistency across different studies and endpoints and taking into account the quality of the testing method, size and power of the study design, biological plausibility, dose-response relationships and statistical association (adequacy of the database). When taking into account the standard information requirements and the completeness and consistency of the database the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

AF for remaining uncertainties:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, there are no remaining uncertainties. Since there are no further uncertainties, the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.15 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):

35

Dose descriptor starting point:

NOAEL

Value:

0.934 mg/kg bw/day

Modified dose descriptor starting point:

NOAEL

Value:

5.23 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

The substance fulfils the REACH Annex VII to Annex XI information requirements in accordance with ECHA guidance R7.5-7.7 (2017) for assessing long-term systemic toxicity. Since no repeated dose dermal study is available, route-to-route extrapolation from the oral exposure route is performed. The starting point is the NOAEL from the 1-year dietary study in dogs; 0.934 mg/kg bw/day. A value of 1 % for dermal absorption (based on in vitro data), was applied together with 4 % oral absorption (based on toxicokinetics) for the route-to-route extrapolation. A correction for 5 day exposure is performed (7 days exposure per week in the study versus 5 days per week for workers): 0.934 * (4/1) * (7/5) = 5.23 mg/kg bw/day.

AF for dose response relationship:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, for the dose-response relationship, consideration should be given to the uncertainties in the dose descriptor (NOAEL, benchmark dose,…) as the surrogate for the true no-adverse-effect-level (NAEL). In this case the starting point for the DNEL calculation is a NOAEL, derived from a study which is of good quality and without uncertainties. Therefore the default assessment factor is 1.

AF for differences in duration of exposure:

2

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, a factor allowing for differences in the experimental exposure duration and the duration of exposure for the worker and scenario under consideration needs to be considered taking into account that a) in general the experimental NOAEL will decrease with increasing exposure times and b) other and more serious adverse effects may appear with increasing exposure times. Consequently, to end up with the most conservative DNEL for repeated dose toxicity, chronic exposure is the ‘worst case’. For a sub-chronic toxicity study, an assessment factor of 2 is to be applied.

AF for interspecies differences (allometric scaling):

1.4

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, differences in metabolic rate (allometric scaling) should be accounted for by extrapolation of doses according to an overall assumption that equitoxic doses (when expressed in mg/kg bw/day) scale with body weight to the power of 0.75. This results in different default allometric scaling factors for the different animal species when compared with humans. For dogs, the default assessment factor is 1.4.

AF for other interspecies differences:

2.5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, interspecies differences result from variation in the sensitivity of species due to differences in toxicokinetics and toxicodynamics. Some of the toxicokinetic differences can be explained by differences in body size (and related differences in basal metabolic rate). As no substance-specific data are available, the standard procedure for threshold effects is followed. As a default, an additional factor of 2.5 for interspecies differences (other than allometric scaling), i.e. toxicokinetic differences not related to metabolic rate (small part) and toxicodynamic differences (larger part) is applied.

AF for intraspecies differences:

5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, intraspecies differences in human result from a multitude of biological factors such as genetic polymorphism affecting e.g. toxicokinetics/metabolism, age, gender, health status and nutritional status. For workers, as standard procedure for threshold effects a default assessment factor of 5 is to be used, based on the fact that this sub population does not cover the very young, the very old, and the very ill.

AF for the quality of the whole database:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, the evaluation of the total toxicological database should include an assessment whether the available information as a whole meets the tonnage driven data requirements necessary to fulfil the REACH requirements, or whether there are data gaps (completeness of the database). Furthermore, the hazard data should be assessed for the reliability and consistency across different studies and endpoints and taking into account the quality of the testing method, size and power of the study design, biological plausibility, dose-response relationships and statistical association (adequacy of the database). When taking into account the standard information requirements and the completeness and consistency of the database the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

AF for remaining uncertainties:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, there are no remaining uncertainties. Since there are no further uncertainties, the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

medium hazard (no threshold derived)

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.002 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):

50

Dose descriptor starting point:

NOAEL

Value:

0.934 mg/kg bw/day

Modified dose descriptor starting point:

NOAEC

Value:

0.093 mg/m³

Explanation for the modification of the dose descriptor starting point:

The substance fulfils the REACH Annex VII to Annex XI information requirements in accordance with ECHA guidance R7.5-7.7 (2017) for assessing long-term systemic toxicity. Since no repeated dose inhalation study is available, route-to-route extrapolation from the oral exposure route is performed. The starting point is the NOAEL from the 1-year dietary study in dogs; 0.934 mg/kg bw/day. This oral dog NOAEL is converted to an inhalation NOAEC for dogs by using a default respiratory volume for the dog corresponding to 24 hours (0.40 m3/kg bw). The values of 4 % oral absorption (based on toxicokinetics) and 100% absorption upon inhalation (worst case standard value) have been used: 0.934 * (1/0.40) * (4/100) = 0.0934 mg/m3.

AF for dose response relationship:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, for the dose-response relationship, consideration should be given to the uncertainties in the dose descriptor (NOAEL, benchmark dose,…) as the surrogate for the true no-adverse-effect-level (NAEL). In this case the starting point for the DNEL calculation is a NOAEL, derived from a study which is of good quality and without uncertainties. Therefore the default assessment factor is 1.

AF for differences in duration of exposure:

2

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, a factor allowing for differences in the experimental exposure duration and the duration of exposure for the worker and scenario under consideration needs to be considered taking into account that a) in general the experimental NOAEL will decrease with increasing exposure times and b) other and more serious adverse effects may appear with increasing exposure times. Consequently, to end up with the most conservative DNEL for repeated dose toxicity, chronic exposure is the ‘worst case’. For a sub-chronic toxicity study, an assessment factor of 2 is to be applied.

AF for interspecies differences (allometric scaling):

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, as long as route-to-route extrapolation is not needed, allometric scaling should not be applied in cases where the dose unit (original or transformed) in experimental animal studies are expressed as concentrations (e.g. in mg/m³ air, ppm in diet, or mg/L in the drinking water) as these are assumed to be already scaled according to the allometric principle, since ventilation rate and food intake directly depend on the basal metabolic rate. In this case, route-to-route extrapolation is performed from an oral feeding study. The derived NOAEL is modified according to allometric principles to a NOAEC (mg/m³), therefore, additional assessment factor for allometric scaling is not needed.

AF for other interspecies differences:

2.5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, interspecies differences result from variation in the sensitivity of species due to differences in toxicokinetics and toxicodynamics. Some of the toxicokinetic differences can be explained by differences in body size (and related differences in basal metabolic rate). As no substance-specific data are available, the standard procedure for threshold effects is followed. As a default, an additional factor of 2.5 for interspecies differences (other than allometric scaling), i.e. toxicokinetic differences not related to metabolic rate (small part) and toxicodynamic differences (larger part) is applied.

AF for intraspecies differences:

10

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, intraspecies differences in human result from a multitude of biological factors such as genetic polymorphism affecting e.g. toxicokinetics/metabolism, age, gender, health status and nutritional status. For consumers, as standard procedure for threshold effects a default assessment factor of 10 is to be used, based on the fact that the all sub-populations are covered in this population: the very young, the very old, and the very ill.

AF for the quality of the whole database:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, the evaluation of the total toxicological database should include an assessment whether the available information as a whole meets the tonnage driven data requirements necessary to fulfil the REACH requirements, or whether there are data gaps (completeness of the database). Furthermore, the hazard data should be assessed for the reliability and consistency across different studies and endpoints and taking into account the quality of the testing method, size and power of the study design, biological plausibility, dose-response relationships and statistical association (adequacy of the database). When taking into account the standard information requirements and the completeness and consistency of the database the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

AF for remaining uncertainties:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, there are no remaining uncertainties. Since there are no further uncertainties, the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

Acute/short term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.19 mg/m³

Most sensitive endpoint:

acute toxicity

Route of original study:

By inhalation

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

2 500

Dose descriptor starting point:

other: LC50

Value:

2.26 mg/m³

Modified dose descriptor starting point:

other: LC50

Value:

474.63 mg/m³

Explanation for the modification of the dose descriptor starting point:

The substance fulfils the REACH Annex VII to Annex XI information requirements in accordance with ECHA guidance R7.5-7.7 (2017) for assessing long-term systemic toxicity. The starting point is the rat inhalation LC50. The LC50 is converted into inhalation worker NOAEC by correction for respiratory rate by using a default respiratory volume for the rat corresponding to 15 minutes (0.012 m3/kg bw) and by correction for 15 minutes peak exposure (4 hours exposure in the study versus 15 minutes for workers). The correction for the duration of exposure is done according to Haber’s law. The Haber’s law constant states that the concentration times the time is a constant. Cⁿ₁x t₁= Cⁿ₂x t₂(for which n=3, since extrapolation to shorter duration), thus (2.26)³x 4 = C³x 0.25, and C = 3 = 5.70 mg/m³. Next, the value is corrected for worker activity and the default respiratory volume: 5.70 * (1/0.012) = 474.63 mg/m3.

AF for dose response relationship:

100

Justification:

An inhalatory DNEL acute is derived by applying a large assessment factor for severity of effect to the (time-scaled, if needed) LC50-value. There is no scientific basis for a default value of this assessment factor (for the extrapolation of a lethal concentration into a NOAEC). Still, a default AF of 100 is suggested as a starting point, but the factor can be modified in light of the whole toxicity database for that substance provided that a sound justification is given. The starting point is the LC50 from acute inhalation study in rats; 0.1 mg/L which translates to 100 mg/m3. An assessment factor of 100 for severity of effect to the LC50 value is applied.

AF for interspecies differences (allometric scaling):

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, as long as route-to-route extrapolation is not needed, allometric scaling should not be applied in cases where the dose unit (original or transformed) in experimental animal studies are expressed as concentrations (e.g. in mg/m³ air, ppm in diet, or mg/L in the drinking water) as these are assumed to be already scaled according to the allometric principle, since ventilation rate and food intake directly depend on the basal metabolic rate. In this case, route-to-route extrapolation is performed from an oral feeding study. The derived NOAEL is modified according to allometric principles to a NOAEC (mg/m³), therefore additional assessment factor for allometric scaling is not needed.

AF for other interspecies differences:

2.5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, interspecies differences result from variation in the sensitivity of species due to differences in toxicokinetics and toxicodynamics. Some of the toxicokinetic differences can be explained by differences in body size (and related differences in basal metabolic rate). As no substance-specific data are available, the standard procedure for threshold effects is followed. As a default, an additional factor of 2.5 for interspecies differences (other than allometric scaling), i.e. toxicokinetic differences not related to metabolic rate (small part) and toxicodynamic differences (larger part) is applied.

AF for intraspecies differences:

10

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, intraspecies differences in human result from a multitude of biological factors such as genetic polymorphism affecting e.g. toxicokinetics/metabolism, age, gender, health status and nutritional status. For consumers, as standard procedure for threshold effects a default assessment factor of 10 is to be used, based on the fact that the all sub-populations are covered in this population: the very young, the very old, and the very ill.

AF for the quality of the whole database:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, the evaluation of the total toxicological database should include an assessment whether the available information as a whole meets the tonnage driven data requirements necessary to fulfil the REACH requirements, or whether there are data gaps (completeness of the database). Furthermore, the hazard data should be assessed for the reliability and consistency across different studies and endpoints and taking into account the quality of the testing method, size and power of the study design, biological plausibility, dose-response relationships and statistical association (adequacy of the database). When taking into account the standard information requirements and the completeness and consistency of the database the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

AF for remaining uncertainties:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, there are no remaining uncertainties. Since there are no further uncertainties, the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Dose descriptor:

other:

Acute/short term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.053 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):

70

Dose descriptor starting point:

NOAEL

Value:

0.934 mg/kg bw/day

Modified dose descriptor starting point:

NOAEL

Value:

3.736 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

The substance fulfils the REACH Annex VII to Annex XI information requirements in accordance with ECHA guidance R7.5-7.7 (2017) for assessing long-term systemic toxicity. Since no repeated dose dermal study is available, route-to-route extrapolation from the oral exposure route is performed. The starting point is the NOAEL from the 1-year dietary study in dogs; 0.934 mg/kg bw/day. A value of 1 % for dermal absorption value (based on in vitro data) was applied together with 4 % oral absorption (based on toxicokinetics) for the route-to-route extrapolation: 0.934 * (4/1) = 3.736 mg/kg bw/day.

AF for dose response relationship:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, for the dose-response relationship, consideration should be given to the uncertainties in the dose descriptor (NOAEL, benchmark dose,…) as the surrogate for the true no-adverse-effect-level (NAEL). In this case the starting point for the DNEL calculation is a NOAEL, derived from a study which is of good quality and without uncertainties. Therefore the default assessment factor is 1.

AF for differences in duration of exposure:

2

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, a factor allowing for differences in the experimental exposure duration and the duration of exposure for the worker and scenario under consideration needs to be considered taking into account that a) in general the experimental NOAEL will decrease with increasing exposure times and b) other and more serious adverse effects may appear with increasing exposure times. Consequently, to end up with the most conservative DNEL for repeated dose toxicity, chronic exposure is the ‘worst case’. For a sub-chronic toxicity study, an assessment factor of 2 is to be applied.

AF for interspecies differences (allometric scaling):

1.4

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, differences in metabolic rate (allometric scaling) should be accounted for by extrapolation of doses according to an overall assumption that equitoxic doses (when expressed in mg/kg bw/day) scale with body weight to the power of 0.75. This results in different default allometric scaling factors for the different animal species when compared with humans. For dogs, the default assessment factor is 1.4.

AF for other interspecies differences:

2.5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, interspecies differences result from variation in the sensitivity of species due to differences in toxicokinetics and toxicodynamics. Some of the toxicokinetic differences can be explained by differences in body size (and related differences in basal metabolic rate). As no substance-specific data are available, the standard procedure for threshold effects is followed. As a default, an additional factor of 2.5 for interspecies differences (other than allometric scaling), i.e. toxicokinetic differences not related to metabolic rate (small part) and toxicodynamic differences (larger part) is applied.

AF for intraspecies differences:

10

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, intraspecies differences in human result from a multitude of biological factors such as genetic polymorphism affecting e.g. toxicokinetics/metabolism, age, gender, health status and nutritional status. For consumers, as standard procedure for threshold effects a default assessment factor of 10 is to be used, based on the fact that the all sub-populations are covered in this population: the very young, the very old, and the very ill.

AF for the quality of the whole database:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, the evaluation of the total toxicological database should include an assessment whether the available information as a whole meets the tonnage driven data requirements necessary to fulfil the REACH requirements, or whether there are data gaps (completeness of the database). Furthermore, the hazard data should be assessed for the reliability and consistency across different studies and endpoints and taking into account the quality of the testing method, size and power of the study design, biological plausibility, dose-response relationships and statistical association (adequacy of the database). When taking into account the standard information requirements and the completeness and consistency of the database the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

AF for remaining uncertainties:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, there are no remaining uncertainties. Since there are no further uncertainties, the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.013 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):

70

Dose descriptor starting point:

NOAEL

Value:

0.934 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

The substance fulfils the REACH Annex VII to Annex XI information requirements in accordance with ECHA guidance R7.5-7.7 (2017) for assessing long-term systemic toxicity. The starting point is the NOAEL from the1-year dietary repeated dose toxicity study in dogs; 0.934 mg/kg bw/day.

AF for dose response relationship:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, for the dose-response relationship, consideration should be given to the uncertainties in the dose descriptor (NOAEL, benchmark dose,…) as the surrogate for the true no-adverse-effect-level (NAEL). In this case the starting point for the DNEL calculation is a NOAEL, derived from a study which is of good quality and without uncertainties. Therefore the default assessment factor is 1.

AF for differences in duration of exposure:

2

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, a factor allowing for differences in the experimental exposure duration and the duration of exposure for the worker and scenario under consideration needs to be considered taking into account that a) in general the experimental NOAEL will decrease with increasing exposure times and b) other and more serious adverse effects may appear with increasing exposure times. Consequently, to end up with the most conservative DNEL for repeated dose toxicity, chronic exposure is the ‘worst case’. For a sub-chronic toxicity study, an assessment factor of 2 is to be applied.

AF for interspecies differences (allometric scaling):

1.4

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, differences in metabolic rate (allometric scaling) should be accounted for by extrapolation of doses according to an overall assumption that equitoxic doses (when expressed in mg/kg bw/day) scale with body weight to the power of 0.75. This results in different default allometric scaling factors for the different animal species when compared with humans. For dogs, the default assessment factor is 1.4.

AF for other interspecies differences:

2.5

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, interspecies differences result from variation in the sensitivity of species due to differences in toxicokinetics and toxicodynamics. Some of the toxicokinetic differences can be explained by differences in body size (and related differences in basal metabolic rate). As no substance-specific data are available, the standard procedure for threshold effects is followed. As a default, an additional factor of 2.5 for interspecies differences (other than allometric scaling), i.e. toxicokinetic differences not related to metabolic rate (small part) and toxicodynamic differences (larger part) is applied.

AF for intraspecies differences:

10

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, intraspecies differences in human result from a multitude of biological factors such as genetic polymorphism affecting e.g. toxicokinetics/metabolism, age, gender, health status and nutritional status. For consumers, as standard procedure for threshold effects a default assessment factor of 10 is to be used, based on the fact that the all sub-populations are covered in this population: the very young, the very old, and the very ill.

AF for the quality of the whole database:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, the evaluation of the total toxicological database should include an assessment whether the available information as a whole meets the tonnage driven data requirements necessary to fulfil the REACH requirements, or whether there are data gaps (completeness of the database). Furthermore, the hazard data should be assessed for the reliability and consistency across different studies and endpoints and taking into account the quality of the testing method, size and power of the study design, biological plausibility, dose-response relationships and statistical association (adequacy of the database). When taking into account the standard information requirements and the completeness and consistency of the database the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

AF for remaining uncertainties:

1

Justification:

In accordance with ECHA Guidance on information requirements and chemical safety assessment – Chapter 8: Characterisation of dose-response for human health, there are no remaining uncertainties. Since there are no further uncertainties, the default assessment factor of 1, to be applied for good/standard quality of the database, is recommended.

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:

medium hazard (no threshold derived)