Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 231-176-9
CAS number: 7440-67-7
Flammability properties of zirconium are highly depend on the form and particular size of the metal.A test performed on zirconium metal (sponge) shows that it is highly flammable according to 67/548/EECIn the powder form and according to its size, Zirconium can be pyrophoric, under specific conditions of moisture (3% to 25% water content) .As stated in the harmonised Classification and Labelling (CLP 1272/2008, annex VI): zirconium powder is classified "pyr sol.1" and "water react 1" zirconium powder dry is classified "self heat 1"
Flammability is usually seen as the ease with which the substance
can burn or be ignited. However it also includes spontaneously
flammability (pyrophoricity) and ignition on contact with water.
The various studies show that zirconium in the powder form
presents a risk of explosion in contact with air according to its
particle size, especially if particles have a diameter lower than 62 µm.
Furthermore, zirconium powder in contact with water (humidity
between 3 % and 25 %) can ignite spontaneously.
According to annex VII, section 7.13 column 2 of the REACH
regulation on standard information requirements, the study does not need
to be conducted when the substance ignites spontaneously with air at
room temperature. Zirconium powder presents risks of spontaneous
ingnition, therefore, the test for zirconium powder is not conducted.
As stated in the harmonised Classification and Labelling (CLP
1272/2008, annex VI):
zirconium powder is classified "pyr sol.1"
zirconium powder dry is classified "self heat 1"
In the daily use and handling of Zirconium sponge during which
continuous exposure to air can occur, no spontaneous ignition is
observed. The absence of structural alerts furthermore confirms that
Zirconium sponge is not expected to have pyrophoric properties.
FLAMMABILITY IN CONTACT WITH WATER
Zirconium powder may ignite in contact with moist air or moisture
(3%-25% humidity) with liberation of flammable gases (H2). It is to be
noted that combustion of zirconium dust in air is enhanced by the
presence of limited amounts of water (5 -10%)
zirconium powder is classified "water react 1"
Under conditions where Zirconium sponge is in contact with water
no ignition and/or liberation of flammable gases is observed. The
absence of structural alerts furthermore confirms that it is highly
unlikely that Zirconium sponge is flammable in contact with water.
A test has been performed by EUROFINS on zirconium shot (>0.5mm,
<2.8mm), following EEC Method A10. This test shows that zirconium shot
is highly flammable according to 67/548/EEC regulation. This result is
chosen for this endpoint and on the basis of expert judgement it is
considered as relevant also for the sponge form.
Zirconium powder is listed on Annex VI of regulation n°1272/2008
of 16 December 2008 :
zirconium powder is classified "pyr sol.1"
(H250: Catches fire spontaneously if exposed to air) and "water react
1" (H 260: In contact with water, releases flammable gases which may
zirconium powder dry is classified "self
heat 1" (H 251: Self-heating; may catch fire)
No change to this classification is proposed.
According to the results (method A 10, 440/2008/CEE regulation), zirconium
sponge is considered as highly flammable (R11) following
According to the 1272/2008/CEE regulation (CLP), proposition for
classification of zirconium sponge as "flammable solid" (H
228), category 1.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again