Triiron tetraoxide

Flammability

Description of key information

a) Flammability: In accordance with section 1 of REACH Annex XI, the study does not need to be conducted. The substance is a mixed oxide (Fe2O3.FeO). Two Iron ions are already in the maximum oxidation stage of +III, and one Iron ion has the oxidation stage of +II. Due to this composition, the reaction with air is expected to be slow which is also confirmed in the A.16 test. Therefore, the substance is not classified as flammable.

b) Flammability on contact with water: In accordance with section 1 of REACH Annex XI, a study does not need to be conducted as the substance is an inert oxide which does not react with water. Flammable gases are not formed in contact with water.

c) Pyrophoric properties: In accordance with section 1 of REACH Annex XI and CLP Annex I, 2.9.4 and 2.10.4, a study on pyrophoric properties does not need to be conducted as it is scientifically unjustified. Based on experience during handling and use, no pyrophoric properties were observed and the structure does not give a reference to pyrophoric properties.

d) Self-heating properties: Based on determinations according to UN-N. 4, the substance does not need to be classified as a self-heating substance. Therefore, triiron tetraoxide is generally not considered to have self-heating properties. However, some types of triiron tetraoxide may trigger a classification.

e) Self-reacting properties: In accordance with Annex I, part 2, section 2.8 of the CLP regulation 1272/2008, a study does not need to be conducted, as there are no chemical groups present in the molecule associated with explosive or self-reactive properties; examples of such groups are given in Tables A6.1 and A6.2 in Appendix 6 of the UN RTDG, Manual of Tests and Criteria.

d) Organic peroxide: In accordance with part 2, section 2.15 of Annex I of the CLP Regulation 1272/2008, the substance does not need to be assessed for organic peroxide properties, as based on its chemical structure, the substance is not an organic peroxide.

Key value for chemical safety assessment

Flammability:

non flammable

Additional information

In order to identify of whether the substance meets the definition of a self-heating substance, determinations were performed according to UN-N.4. The magnetite pigment being most sensitive to oxidation reactions could be at stored in a volume of 27 m³ at a temperature of 50 °C without any incidence of auto-ignition, although the Bowes-Cameron cages test at a volume of 1 Liter imply otherwise. At the 18th meeting of the "Committee of Experts on the Transport of Dangerous Goods" , November 28th - 30th, 1994 in Geneva magnetite was therefore excluded from the constraints of transport class 4.2 up to a volume 3 m³ per single packaging.

Justification for classification or non-classification

The substance is not flammable, it has no pyrophoric properties, no flammability in contact with water, is generally not a self-heating substance, is not a self-reactive substance, is not an organic peroxide; and hence no classification according to both Directive 67/548/EEC and GHS (Regulation EC 1272/2008) is required. Some types of triiron tetraoxide may trigger classification cat 1 or 2 with specific signal words, hazard statements and labels.