6-methylhept-5-en-2-one

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

29.39 mg/m³

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

other: ECETOC Technical Report No. 110 (October, 2010)

Overall assessment factor (AF):

6

Dose descriptor starting point:

NOAEL

Value:

200 mg/kg bw/day

Modified dose descriptor starting point:

NOAEC

Value:

176.32 mg/m³

Explanation for the modification of the dose descriptor starting point:

Based on ECHA Guidance R8, v2.1 Nov-2012

Route-to-route extrapolation: 2

In the absence of route-specific information on the starting route, it is proposed to include a default factor of 2 (i.e. the absorption percentage for the starting route is half that of the end route) in the case of oral-to-inhalation extrapolation (ECHA Guidance R8, v2.1 Nov-2012, page 19). This assessment factor is included in the NOAEC calculation (multiplication by 0.5).

Bioavailability differences between  human and animal species: 1

No evidence for a difference between species for oral  exposure to test substance.

Bioavailability differences between test and target substances: 1

The available information is for the substance itself.

Modification for exposure (experiment in animal and human): 2.63

For workers 8 hours exposure/day is assumed. recalculation of the oral NOAEL to a NOAEC is done based on the respiratory voume of the rat: 1/sRV rat (8h)=  1/0.38 m3/kg/d = 2.63 (based on ECHA Guidance R8, v2.1 Nov-2012, page 20). This assessment factor is included in the NOAEC calculation.

Modification for the respiratory volume: 0.67

A correction is done for the repiratory volume during light activity (worker): 8 hours sRV human = 6.7 m3/kg/day / exposure of 10 m3 for light activity (wRV) = 0.67 (based on ECHA Guidance R8, v2.1 Nov-2012, page 20). This assessment factor is included in the NOAEC calculation.

Total modification factor: 0.88

AF for dose response relationship:

1

Justification:

When the starting point for the DNEL calculation is a NOAEL, the default assessment factor as a standard procedure is 1 (identical for ECHA Guidance and ECETOC TR 110).

AF for differences in duration of exposure:

2

Justification:

For extrapolation of sub-chronic to chronic duration of exposure a default assessment factor of 2 is applied (identical for ECHA Guidance and ECETOC TR 110).

AF for interspecies differences (allometric scaling):

1

Justification:

Allometric scaling factor is not applied because the starting point has been corrected for differences in respiratory volume and this takes account of differences in metabolic rates (identical for ECHA Guidance and ECETOC TR 110).

AF for other interspecies differences:

1

Justification:

ECETOC (ECETOC TR No. 110 (2010)) supports the inclusion of the factor for allometry, but considers that routine application of the factor of 2.5 is unjustified as a default factor. Interspecies extrapolation for systemic effects of methylheptenone has to consider both toxicokinetic and toxicodynamic aspects. The toxicokinetics of methylheptenone is covered by the principle of allometric scaling, the starting point has been corrected for differences in respiratory volume and this takes account of differences in metabolic rates, as the default approach. Allometry is generally accepted in the scientific community when the parent chemical or a stable metabolite is the toxic entity that is metabolically detoxified and when renal excretion is the predominant route of elimination. The factor 2.5 for remaining differences including toxicodynamics is considered unnecessary in this case.

AF for intraspecies differences:

3

Justification:

There is a major difference in the AF proposed by the REACH TGD and ECETOC for intraspecies extrapolation of systemic effects if the Point Of Departure is derived from animal studies. For worker, the REACH Guidance suggests a factor of 5 while ECETOC proposes a factor of 3. The proposal of ECETOC is based on an evaluation of the available scientific literature while the REACH TGD refers to standard default procedures. Therefore, it is proposed to follow the ECETOC guideline until the scientific basis for using an alternative approach has been established (ECETOC TR No. 110 (2010)).

AF for the quality of the whole database:

1

Justification:

An additional assessment factor of 1 is considered appropriate, as the repeated dose toxicity of Methylheptenone has well been studied in reliable 90-day oral toxicity study.

AF for remaining uncertainties:

1

Justification:

There are no remaining uncertainties 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:

8.33 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):

24

Dose descriptor starting point:

NOAEL

Value:

200 mg/kg bw/day

Modified dose descriptor starting point:

NOAEL

Value:

200 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

Route-to-route extrapolation: 1

On the assumption that, in general, dermal absorption will not be higher than oral absorption, no factor should be introduced when performing oral-to-dermal extrapolation.

Bioavailability: 1

There is no evidence for a difference between species for oral (or dermal) exposure to the test substance and the available data is for the substance itself.

Modification for exposure: 1

This is not applicable for this route.

AF for dose response relationship:

1

Justification:

When the starting point for the DNEL calculation is a NOAEL, the default assessment factor as a standard procedure is 1 (identical for ECHA Guidance and ECETOC TR 110).

AF for differences in duration of exposure:

2

Justification:

For extrapolation of sub-chronic to chronic duration of exposure a default assessment factor of 2 is applied (identical for ECHA Guidance and ECETOC TR 110).

AF for interspecies differences (allometric scaling):

4

Justification:

This is the standard factor for interspecies differences (allometric scaling) from rat to human (identical for ECHA Guidance and ECETOC TR 110).

AF for other interspecies differences:

1

Justification:

ECETOC (ECETOC TR No. 110 (2010)) supports the inclusion of the factor for allometry, but considers that routine application of the factor of 2.5 is unjustified as a default factor. Interspecies extrapolation for systemic effects of methylheptenone has to consider both toxicokinetic and toxicodynamic aspects. The toxicokinetics of methylheptenone is covered by the principle of allometric scaling, the starting point has been corrected for differences in respiratory volume and this takes account of differences in metabolic rates, as the default approach. Allometry is generally accepted in the scientific community when the parent chemical or a stable metabolite is the toxic entity that is metabolically detoxified and when renal excretion is the predominant route of elimination. The factor 2.5 for remaining differences including toxicodynamics is considered unnecessary in this case.

AF for intraspecies differences:

3

Justification:

There is a major difference in the AF proposed by the REACH TGD and ECETOC for intraspecies extrapolation of systemic effects if the Point Of Departure is derived from animal studies. For worker, the REACH Guidance suggests a factor of 5 while ECETOC proposes a factor of 3. The proposal of ECETOC is based on an evaluation of the available scientific literature while the REACH TGD refers to standard default procedures. Therefore, it is proposed to follow the ECETOC guideline until the scientific basis for using an alternative approach has been established (ECETOC TR No. 110 (2010)).

AF for the quality of the whole database:

1

Justification:

An additional assessment factor of 1 is considered appropriate, as the repeated dose toxicity of Methylheptenone has well been studied in reliable 90-day oral toxicity study.

AF for remaining uncertainties:

1

Justification:

There are no remaining uncertainties 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

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

no hazard identified

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

8.7 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):

10

Dose descriptor starting point:

NOAEL

Value:

200 mg/kg bw/day

Modified dose descriptor starting point:

NOAEC

Value:

86.96 mg/m³

Explanation for the modification of the dose descriptor starting point:

Based on ECHA Guidance R8, v2.1 Nov-2012

Route-to-route extrapolation: 2

In the absence of route-specific information on the starting route, it is proposed to include a default factor of 2 (i.e. the absorption percentage for the starting route is half that of the end route) in the case of oral-to-inhalation extrapolation (ECHA Guidance R8, v2.1 Nov-2012, page 19). This assessment factor is included in the NOAEC calculation (multiplication by 0.5).

Bioavailability differences between human and animal species: 1

No evidence for a difference between species for oral exposure to test substance.

Bioavailability differences between test and target substances: 1

The available information is for the substance itself.

Modification for exposure (experiment in animal and human): 0.87

For consumer 24 hours exposure/day is assumed. Recalculation of the oral NOAEL to a NOAEC is done based on the respiratory voume of the rat: 1/sRV rat (24h)=  1/1.15 m3/kg/d = 0.87 (based on ECHA Guidance R8, v2.1 Nov-2012, page 20). This assessment factor is included in the NOAEC calculation.

Modification for the respiratory volume: 1

Not applicable for consumers (24 hours exposure expected).

Total modification factor: 0.43

AF for dose response relationship:

1

Justification:

When the starting point for the DNEL calculation is a NOAEL, the default assessment factor as a standard procedure is 1 (identical for ECHA Guidance and ECETOC TR 110).

AF for differences in duration of exposure:

2

Justification:

For extrapolation of sub-chronic to chronic duration of exposure a default assessment factor of 2 is applied (identical for ECHA Guidance and ECETOC TR 110).

AF for interspecies differences (allometric scaling):

1

Justification:

Allometric scaling factor is not applied because the starting point has been corrected for differences in respiratory volume and this takes account of differences in metabolic rates (identical for ECHA Guidance and ECETOC TR 110).

AF for other interspecies differences:

1

Justification:

ECETOC (ECETOC TR No. 110 (2010)) supports the inclusion of the factor for allometry, but considers that routine application of the factor of 2.5 is unjustified as a default factor. Interspecies extrapolation for systemic effects of methylheptenone has to consider both toxicokinetic and toxicodynamic aspects. The toxicokinetics of methylheptenone is covered by the principle of allometric scaling, the starting point has been corrected for differences in respiratory volume and this takes account of differences in metabolic rates, as the default approach. Allometry is generally accepted in the scientific community when the parent chemical or a stable metabolite is the toxic entity that is metabolically detoxified and when renal excretion is the predominant route of elimination. The factor 2.5 for remaining differences including toxicodynamics is considered unnecessary in this case.

AF for intraspecies differences:

5

Justification:

There is a major difference in the AF proposed by the REACH TGD and ECETOC for intraspecies extrapolation of systemic effects if the Point Of Departure is derived from animal studies. For consumer, the REACH Guidance suggests a factor of 10 while ECETOC proposes a factor of 5. The proposal of ECETOC is based on an evaluation of the available scientific literature while the REACH TGD refers to standard default procedures. Therefore, it is proposed to follow the ECETOC guideline until the scientific basis for using an alternative approach has been established (ECETOC TR No. 110 (2010)).

AF for the quality of the whole database:

1

Justification:

An additional assessment factor of 1 is considered appropriate, as the repeated dose toxicity of Methylheptenone has well been studied in reliable 90-day oral toxicity study.

AF for remaining uncertainties:

1

Justification:

There are no remaining uncertainties 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:

5 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):

40

Dose descriptor starting point:

NOAEL

Value:

200 mg/kg bw/day

Modified dose descriptor starting point:

NOAEL

Value:

200 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

Route-to-route extrapolation: 1

On the assumption that, in general, dermal absorption will not be higher than oral absorption, no factor should be introduced when performing oral-to-dermal extrapolation.

Bioavailability: 1

There is no evidence for a difference between species for oral (or dermal) exposure to the test substance and the available data is for the substance itself.

Modification for exposure: 1

This is not applicable for this route.

AF for dose response relationship:

1

Justification:

When the starting point for the DNEL calculation is a NOAEL, the default assessment factor as a standard procedure is 1 (identical for ECHA Guidance and ECETOC TR 110).

AF for differences in duration of exposure:

2

Justification:

For extrapolation of sub-chronic to chronic duration of exposure a default assessment factor of 2 is applied (identical for ECHA Guidance and ECETOC TR 110).

AF for interspecies differences (allometric scaling):

4

Justification:

This is the standard factor for interspecies differences (allometric scaling) from rat to human (identical for ECHA Guidance and ECETOC TR 110).

AF for other interspecies differences:

1

Justification:

ECETOC (ECETOC TR No. 110 (2010)) supports the inclusion of the factor for allometry, but considers that routine application of the factor of 2.5 is unjustified as a default factor. Interspecies extrapolation for systemic effects of methylheptenone has to consider both toxicokinetic and toxicodynamic aspects. The toxicokinetics of methylheptenone is covered by the principle of allometric scaling, the starting point has been corrected for differences in respiratory volume and this takes account of differences in metabolic rates, as the default approach. Allometry is generally accepted in the scientific community when the parent chemical or a stable metabolite is the toxic entity that is metabolically detoxified and when renal excretion is the predominant route of elimination. The factor 2.5 for remaining differences including toxicodynamics is considered unnecessary in this case.

AF for intraspecies differences:

5

Justification:

There is a major difference in the AF proposed by the REACH TGD and ECETOC for intraspecies extrapolation of systemic effects if the Point Of Departure is derived from animal studies. For consumer, the REACH Guidance suggests a factor of 10 while ECETOC proposes a factor of 5. The proposal of ECETOC is based on an evaluation of the available scientific literature while the REACH TGD refers to standard default procedures. Therefore, it is proposed to follow the ECETOC guideline until the scientific basis for using an alternative approach has been established (ECETOC TR No. 110 (2010)).

AF for the quality of the whole database:

1

Justification:

An additional assessment factor of 1 is considered appropriate, as the repeated dose toxicity of Methylheptenone has well been studied in reliable 90-day oral toxicity study.

AF for remaining uncertainties:

1

Justification:

There are no remaining uncertainties 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

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

5 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

Dose descriptor starting point:

NOAEL

Value:

200 mg/kg bw/day

Modified dose descriptor starting point:

NOAEL

Value:

200 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

Route-to-route extrapolation: 1

Not required as available study is for the oral route.

Bioavailability: 1

There is no evidence for a difference between species for oral exposure to the test substance and the available data is for the substance itself.

Modification for exposure: 1

This is not applicable for this route.

AF for dose response relationship:

1

Justification:

When the starting point for the DNEL calculation is a NOAEL, the default assessment factor as a standard procedure is 1 (identical for ECHA Guidance and ECETOC TR 110).

AF for differences in duration of exposure:

2

Justification:

For extrapolation of sub-chronic to chronic duration of exposure a default assessment factor of 2 is applied (identical for ECHA Guidance and ECETOC TR 110).

AF for interspecies differences (allometric scaling):

4

Justification:

This is the standard factor for interspecies differences (allometric scaling) from rat to human (identical for ECHA Guidance and ECETOC TR 110).

AF for other interspecies differences:

1

Justification:

ECETOC (ECETOC TR No. 110 (2010)) supports the inclusion of the factor for allometry, but considers that routine application of the factor of 2.5 is unjustified as a default factor. Interspecies extrapolation for systemic effects of methylheptenone has to consider both toxicokinetic and toxicodynamic aspects. The toxicokinetics of methylheptenone is covered by the principle of allometric scaling, the starting point has been corrected for differences in respiratory volume and this takes account of differences in metabolic rates, as the default approach. Allometry is generally accepted in the scientific community when the parent chemical or a stable metabolite is the toxic entity that is metabolically detoxified and when renal excretion is the predominant route of elimination. The factor 2.5 for remaining differences including toxicodynamics is considered unnecessary in this case.

AF for intraspecies differences:

5

Justification:

There is a major difference in the AF proposed by the REACH TGD and ECETOC for intraspecies extrapolation of systemic effects if the Point Of Departure is derived from animal studies. For worker, the REACH Guidance suggests a factor of 10 while ECETOC proposes a factor of 5. The proposal of ECETOC is based on an evaluation of the available scientific literature while the REACH TGD refers to standard default procedures. Therefore, it is proposed to follow the ECETOC guideline until the scientific basis for using an alternative approach has been established (ECETOC TR No. 110 (2010)).

AF for the quality of the whole database:

1

Justification:

An additional assessment factor of 1 is considered appropriate, as the repeated dose toxicity of Methylheptenone has well been studied in reliable 90-day oral toxicity study.

AF for remaining uncertainties:

0

Justification:

There are no remaining uncertainties identified.

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