Barium chromate

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

DMEL (Derived Minimum Effect Level)

Value:

0.01 mg/m³

Most sensitive endpoint:

carcinogenicity

Acute/short term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.01 mg/m³

Most sensitive endpoint:

carcinogenicity

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

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:

no hazard identified

Additional information - workers

BaCrO4 is a salt and will release Ba or Cr ions (transformation products via hydrolysis, dissociation,…). These ions will be responsible for any potential environmental and human systemic effect, rather than the initial non-transformed substance.

Barium and chromium are both natural elements, natural part of the earth’s crust and present in natural background concentrations in all environmental compartments.

 

Due to several physico-chemical processes, chromium can exist in different chemical forms, some of which are more bioavailable and toxic than others (depending on pH, hardness and dissolved organic matter, for instance). In particular, a significant difference may exist between Cr(VI) and Cr(III), which are the most stable oxidation states of chromium at pH range of natural waters. Once Cr (VI) is released in the environment, reduction will occur. Cr(VI) can be removed naturally in water by reductants such as aqueous Fe(II), dissolved humic acids, and Fe(II)-bearing minerals and Cr(III) will be formed. Cr (VI) in the air reacts with dust particles or other pollutants to form Cr(III). The environmental effects assessment is therefore based on the Cr(III) assessment.

 

As widely reported in relevant chromate assessments (i.e. RAR 2005, INERIS 2005), in aquatic environment, adsorption of Cr(VI) to particulate matter decreases when pH increases and competing dissolved anions are present. On the other hand, Cr(III) adsorption increases with pH and decreases where competing dissolved cations are present. Under the same conditions, Cr(III) adsorption to particulate matter is higher than Cr(VI). In sediment, reduction of Cr(VI) to Cr(III) is expected in anaerobic sediments: at environmental pH, adsorption of Cr(III) to sediment is likely to occur and when pH decreases below 5, Cr(III) becomes more mobile.

The behaviour of Cr(VI) in soil is similar to its behaviour in sediment compartment. Adsorption to the soil matrix is expected to increase with increasing acidity of the soil. Under neutral to alkaline conditions Cr(VI) is expected to become highly mobile in soil. Furthermore, it may leach into anaerobic layers where reduction to Cr(III) would be expected. As for sediment, Cr(III) is expected to be rapidly and strongly adsorbed into soil. In groundwater, Cr(VI) is reduced to Cr(III) in presence of low oxygen concentration or reducing conditions.

 

For human health, it can not be assumed that Cr (VI) is rapidly reduced to the less toxic Cr (III) and consequently, Cr (VI) is assumed for human health

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

DMEL (Derived Minimum Effect Level)

Value:

0.01 mg/m³

Most sensitive endpoint:

carcinogenicity

Acute/short term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.01 mg/m³

Most sensitive endpoint:

carcinogenicity

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

high hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

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:

high hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

medium hazard (no threshold derived)

DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:

no hazard identified

Additional information - General Population

BaCrO4 is a salt and will release Ba or Cr ions (transformation products via hydrolysis, dissociation,…). These ions will be responsible for any potential environmental and human systemic effect, rather than the initial non-transformed substance.

Barium and chromium are both natural elements, natural part of the earth’s crust and present in natural background concentrations in all environmental compartments.

 

Due to several physico-chemical processes, chromium can exist in different chemical forms, some of which are more bioavailable and toxic than others (depending on pH, hardness and dissolved organic matter, for instance). In particular, a significant difference may exist between Cr(VI) and Cr(III), which are the most stable oxidation states of chromium at pH range of natural waters. Once Cr (VI) is released in the environment, reduction will occur. Cr(VI) can be removed naturally in water by reductants such as aqueous Fe(II), dissolved humic acids, and Fe(II)-bearing minerals and Cr(III) will be formed. Cr (VI) in the air reacts with dust particles or other pollutants to form Cr(III). The environmental effects assessment is therefore based on the Cr(III) assessment.

 

As widely reported in relevant chromate assessments (i.e. RAR 2005, INERIS 2005), in aquatic environment, adsorption of Cr(VI) to particulate matter decreases when pH increases and competing dissolved anions are present. On the other hand, Cr(III) adsorption increases with pH and decreases where competing dissolved cations are present. Under the same conditions, Cr(III) adsorption to particulate matter is higher than Cr(VI). In sediment, reduction of Cr(VI) to Cr(III) is expected in anaerobic sediments: at environmental pH, adsorption of Cr(III) to sediment is likely to occur and when pH decreases below 5, Cr(III) becomes more mobile.

The behaviour of Cr(VI) in soil is similar to its behaviour in sediment compartment. Adsorption to the soil matrix is expected to increase with increasing acidity of the soil. Under neutral to alkaline conditions Cr(VI) is expected to become highly mobile in soil. Furthermore, it may leach into anaerobic layers where reduction to Cr(III) would be expected. As for sediment, Cr(III) is expected to be rapidly and strongly adsorbed into soil. In groundwater, Cr(VI) is reduced to Cr(III) in presence of low oxygen concentration or reducing conditions.

 

For human health, it can not be assumed that Cr (VI) is rapidly reduced to the less toxic Cr (III) and consequently, Cr (VI) is assumed for human health