Calcium

Endpoint summary

Additional information

The environmental fate and pathways endpoint data are waived based on the following:

1)     In accordance with REACH Annex XI.2 testing of elemental calcium (Ca) is not possible due to Ca reactivity in water

2)     Ca is an inorganic substance

3)     In accordance with Annex XI.3 and Column 2 adaptations statements, testing is not necessary as the exposure of Ca (metal) to aquatic, sediment and soil compartments are unlikely.

 

(1) Testing is not technically feasible because of Ca reactivity in water. Based on the known chemistry of alkaline earth metals, Ca metal reacts with water, evolving hydrogen gas. In powdered form the reaction with water is extremely rapid. In the Ca-water reaction calcium dihydroxide (Ca(OH)2) is formed. Therefore, testing of elemental Ca is not technically feasible.

(2) Ca is inorganic, and most of the environmental fate endpoint studies, e.g. biodegradation and hydrolysis, are not relevant for inorganic substances.

 

(3) The exposure based considerations of Ca in its use applications indicate that environmental fate and pathways in water, soil and sediment compartments are not considered to be relevant for elemental calcium. These exposure considerations are based on the general knowledge of the processes. Elemental Ca is used in iron, steel and alloy manufacturing processes mostly in massive forms such as lumps, turnings and strips or granules of 2-7 mm. Calcium’s role in the steel and alloy manufacturing processes is to scavenge the molten metal for oxygen; effectively serving as an antioxidant. The life cycle of Ca metal in these processes ends with reaction on use; therefore there is no exposure to Ca (metal form) after it is introduced into the furnace. Ca metal will immediately react under the extreme heat conditions of these processes to form CaO which may be emitted as a component of the fume or dust from the furnace or become part of the slag.The chemical safety assessment is not indicating the need to further investigate the environmental fate and pathways of elemental Ca in its life-cycle at iron, steel and alloy manufacturing processes.

Also, because Ca is not naturally found in its elemental state, the decision which environmental endpoints are relevant is based on the exposure and the bioavailability considerations of Ca in its whole life-cycle. Therefore, the approach in the chemical safety assessment of elemental Ca was to take into account data from relevant Ca compounds if necessary, when considering the environmental fate and pathways of Ca in its use applications.

The slag formed in the process, and containing CaO, may be applied to soil, at which point emission to soil is possible. However, adverse environmental effects are not expected based on the non-hazardous properties of these by-products produced in the end of the life cycle of Ca use in steel and iron manufacture.The main by-products in Ca use in metallurgical processes are furnace and steel slags. Because of the non-hazardous nature, these slags are widely re-used in soil and ground construction all over the Europe. These by-products are also used as calcification materials to replace limestone in the soil improvement purposes. Certain iron slags (e.g. Thomas slag) are presented in the list of fertilizers in the regulation (EC) No 2003/2003 of the European Parliament and the Council relating to fertilizers(OJ L 304; 21.11.2003). Also, the national list of fertilizers exists were steel and furnace slags are approved by-products to be used as calcification in soil improvement (e.g.Annex 1C 2 (the list of Finnish national fertilizers)of the Finnish Ministry of Agriculture and Forestry regulation No 12/2007).

Also, no Ca-reaction with water to form Ca(OH)2 happens in these processes. Hence, direct or indirect exposure of the aquatic and soil compartment is unlikely. See CSR Chapter 9 for supporting information.