Diammonium dimolybdate

Flammability

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

substances / mixtures which in contact with water emit flammable gases

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is known to be soluble in water to form a stable mixture

Reference 2

Endpoint:

pyrophoric solids

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reference 3

Endpoint:

flammable solids

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Description of key information

Ammonium dimolybdate is not a flammable solid. It does not exhibit pyrophoric properties, nor does it react with water under formation of flammable reaction products (see justification for classification or non-classification).

Key value for chemical safety assessment

Flammability:

not classified

Justification for classification or non-classification

No classification required. Ammonium dimolybdate is not a flammable solid. It does not exhibit pyrophoric properties, nor does it react with water under formation of flammable reaction products.

Flammability is not considered to be relevant for this inorganic compound in which the metal is in its highest possible oxidation state (+VI for Mo), and which therefore are incapable of further reaction with oxygen. Upon heating, ammonium dimolybdate decomposes from ca. 150 °C under evolution of ammonia. No ignition is observed. This substance can thus be designated as non-flammable. (Guidance on information requirements and chemical safety assessment Chapter R.7a: Endpoint specific guidance, section R.7.1.10.3, Dezember 2016). Further, an experimental study on the flammability of molybdenum metal powder has shown that molybdenum is not flammable in the elemental state. In conclusion, flammability cannot be expected for ammonium dimolybdate.

Pyrophoric properties are not plausible, since ammonium dimolybdate is stable at ambient temperature (decomposition under formation of ammonia from ca. 150 °C). This substance also does not contain any chemical groups that might lead to spontaneous ignition a short time after coming in contact with air at room temperature. Furthermore, long-term industrial experience in handling shows that ammonium dimolybdate does not show any pyrophoric properties.

Flammability in contact with water is not considered to be relevant, because the substance does not contain groups that might lead to a reaction with water or damp air, leading to the development of dangerous amounts of gas or gases which may be highly flammable. Furthermore, recent experimental testing for water solubility has also not reported any formation of gases. In contrast, ammonium dimolybdate dissolves readily in water at over 200 g/L.