Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
1.6 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
Modified dose descriptor starting point:
NOAEC
Value:
18 mg/m³
Explanation for the modification of the dose descriptor starting point:

Available data do not suggest a pronounced difference between oral and inhalation route. Due to a lack of experimental data the NOAEC (corr) was derived including ECHAs recommended absorption rates for exposure via the oral (50%) and inhalation (100%) route.

AF for dose response relationship:
1
Justification:
default
AF for differences in duration of exposure:
2
Justification:
ECHA default for sub-chronic to chronic
AF for interspecies differences (allometric scaling):
1
Justification:
default (inhalation)
AF for other interspecies differences:
1
Justification:
see below
AF for intraspecies differences:
5
Justification:
default (worker)
AF for the quality of the whole database:
1
Justification:
default
AF for remaining uncertainties:
1
Justification:
default
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:
no hazard 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

Additional information - workers

Mo2C is used in industrial settings only. There was no indication of concern regarding dermal exposure. For exposure by inhalation, a DNEL of 1.6 mg/m3 was derived. Route-to-route extrapolation is based on an oral NOAEL of 18 mg/kg/d from a 90d study in rat [Calculation: NOAEC (corr) = NOAEL (oral) x (0.38 m3/kg/d)-1 x 6.7 m3/10 m3 x 50%/100%]. Following uptake, all molybdenum substances (regardless of their speciation, valence and solubility) have been demonstrated to have transformed to molybdate anions; this is based on chemical reactivity and thermodynamics and is therefore independent of animal species or human biology. Molybdate anions are absorbed into the body by passive diffusion and not via selective transport mechanism. Upon uptake, they are distributed widely in the body, but accumulation in organ tissues does not occur. Any metabolism of molybdenum substances as such can be excluded, as update, distribution and elimination occurs with the molybdate ion. Therefore, it is considered justified to replace the default assessment factor 2.5 accounting for a correction for remaining differences by “1”.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard 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:
no hazard 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:
no hazard 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

Additional information - General Population

No exposure of the general population expected. The substance is only used in industrial settings.