Combustible Metal Dust Explosion – TITANIUM and ZIRCONIUM

16th July 2014 CSB released their final case study on metal dust explosion (December 9, 2010) which resulted in three deaths and one injury. The facility milled and processed scrap titanium and zirconium metal.

CSB findings reveal that solid organic materials and most metals will cause explosion if the particle size is small enough and are dispersed in sufficient concentration in a confined area.

 

Read full report here

 

Transport regulations lists Titanium powder and Zirconium as below

TITANIUM POWDER, DRY                                                              – Class 4.2           UN Number 2546

TITANIUM POWDER, WETTED                                                     – Class 4.1            UN Number 1352

ZIRCONIUM POWDER, DRY                                                          – Class 4.2           UN Number 2008

ZIRCONIUM POWDER, WETTED                                                  – Class 4.1           UN Number 1358

ZIRCONIUM POWDER, WETTED                                                  – Class 4.1           UN Number 1358

ZIRCONIUM, SCRAP                                                                          – Class 4.2           UN Number 1932

ZIRCONIUM, SUSPENDED IN A FLAMMABLE LIQUID          – Class 3               UN Number 1308

TEAR GAS CANDLES

Tear gas candles are used by police and or civil defence for crowd control.  These candles are articles containing a fuse and other chemicals which when activated will disperse fine chemicals which will cause extreme eye irritation and profuse tears.

Braving Tear Gas near the AUC
Braving Tear Gas near the AUC (Photo credit: Wikipedia)

A typical candle may contain Barium Chromate, Manganese Powder, Lead Chromate, Nitrocellulose, Red Iron Oxide, Titanium Powder, Zirconium Powder, Potassium Chlorate, Sugar, Magnesium Carbonate, etc.

These articles, TEAR GAS CANDLES, are classified as toxic substances with subsidiary risk flammable solids, class 6.1/4.1, by IMDG Code.  See entry UN 1700.

METAL POWDERS

Metal Powders are extremely flammable and very difficult to extinguish once it is burning.

Below metal powders are considered as dangerous goods by transport regulations.

Aluminium powder, coated
Hafnium powder, wetted with not less than 25% water
Titanium powder, wetted with not less than 25% water
Zirconium powder, wetted with not less than 25% water
Pyrophoric alloy or pyrophoric metal, n.o.s.
Aluminium powder, uncoated
Aluminium silicon powder, uncoated
Magnesium powder
Zinc ashes
Zinc dust or zinc powder
Barium alloys, pyrophoric
Zirconium powder, dry
Zirconium, dry, sheets, strip or coiled wire
Hafnium powder, dry
Titanium powder, dry

Titanium metal powder
Titanium metal powder (Photo credit: Wikipedia)

Titanium sponge powders
Metal catalyst, dry
Magnesium granules, coated, particle size not less than 149 microns
Cerium, turnings or gritty powder
Aluminium smelting by-products