Magnesium bis(2-ethylbutanoate)

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

8.5 mg/m³

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

50

Modified dose descriptor starting point:

NOAEC

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

2.41 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

100

Modified dose descriptor starting point:

NOAEL

Acute/short term exposure

DNEL related information

Additional information - workers

Note 1

The systemic long-term DNEL for workers via dermal exposure is calculated starting from the oral repeated dose NOAEL via route-to-route extrapolation. No toxicokinetic information is available for the test substance. Therefore, correction of the dose descriptor taking into account the differences in absorption between routes (dermal vs oral) and between species (rat vs human) is not possible. As a consequence it is assumed that dermal absorption in humans will be equal to oral absorption in rats. This is a worst-case scenario as it is generally accepted that dermal absorption will not be higher than oral absorption (cfr. ECHA guidance R8 section 8.4.2). Furthermore, penetration through rodent skin is generally considered to be faster than penetration through human skin (cfr. textbook Casarett & Doul, 2001, p.656).

The DNEL is thus calculated directly by dividing the oral repeated dose NOAEL (241 mg/kg bw/d) by the relevant assessment factors: 4*2.5 for allometric scaling, 5 for intraspecies differences and 2 for duration of exposure = 2.41 mg/kg bw.

Note 2

The systemic long-term DNEL for workers via inhalation is calculated starting from the oral repeated dose NOAEL via route-to-route extrapolation. The modification of the starting point is performed according to the procedure described in the ECHA guidance R8 Appendix R8 -2. The resulting NAEC (worker) is 424.9 mg/m³. Subsequently, the DNEL is calculated using the following assessment factors: 2 for oral-to-inhalation extrapolation, 5 for intraspecies differences, 2 for duration of exposure and 2.5 for allometric scaling, differences not related to calorimetric differences = 8.50 mg/m³.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

2.1 mg/m³

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

100

Modified dose descriptor starting point:

NOAEC

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

1.21 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

200

Modified dose descriptor starting point:

NOAEL

Acute/short term exposure

DNEL related information

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

1.21 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

200

Modified dose descriptor starting point:

NOAEL

Acute/short term exposure

DNEL related information

Additional information - General Population

Note 3

The systemic long-term DNEL for the general population via dermal exposure is calculated starting from the oral repeated dose NOAEL via route-to-route extrapolation. No toxicokinetic information is available for the test substance. Therefore, correction of the dose descriptor taking into account the differences in absorption between routes (dermal vs oral) and between species (rat vs human) is not possible. As a consequence it is assumed that dermal absorption in humans will be equal to oral absorption in rats. This is a worst-case scenario as it is generally accepted that dermal absorption will not be higher than oral absorption (cfr. ECHA guidance R8 section 8.4.2). Furthermore, penetration through rodent skin is generally considered to be faster than penetration through human skin (cfr. textbook Casarett & Doul, 2001, p.656).

The DNEL is thus calculated directly by dividing the oral repeated dose NOAEL (241 mg/kg bw/d) by the relevant assessment factors: 4*2.5 for allometric scaling, 10 for intraspecies differences and 2 for duration of exposure = 1.21 mg/kg bw.

Note 4

The systemic long-term DNEL for workers via inhalation is calculated starting from the oral repeated dose NOAEL via route-to-route extrapolation. The modification of the starting point is performed according to the procedure described in the ECHA guidance R8 Appendix R8 -2. The resulting NAEC (worker) is 209.6 mg/m³. Subsequently, the DNEL is calculated using the following assessment factors: 2 for oral-to-inhalation extrapolation, 10 for intraspecies differences, 2 for duration of exposure and 2.5 for allometric scaling, differences not related to calorimetric differences = 2.10 mg/m³.

Note 5:

As an oral repeated dose NOAEL is available, no correction of the dose descriptor nor route-to-route extrapolation is required. The DNEL is thus calculated starting from the mentioned NOAEL (241 mg/kg bw/d) by dividing it by the following assessment factors: 4*2.5 for allometric scaling, 10 for intraspecies differences and 2 for duration of exposure = 1.21 mg/kg bw.