Finds cyanide in substances with a pH of 0-14 (a cyanide mixed with a non-metallic acid precursor such as phosphorous pentoxide will have a pH of 0-1 but not release the cyanide until mixed with water)
 
Some cyanide salts are insoluble in water or have a neutral pH. These cyanides still react with acids and are hazardous:
Copper-CN pH 7
Mercuric-CN pH 8
Silver-CN pH 8
Zinc-CN pH 7
 
Finds cyanide in samples that test +ve as Oxidizers
Other tests state: “Samples that test +ve oxidizer cannot contain “CN”.  
Not true.
Oxidizers such as sodium hypochlorite & hydrogen peroxide convert cyanide to cyanate removing the “CN hazard” but many other oxidizers do not have that effect on cyanides.
Oxidizers that can be mixed with CN salts without converting them to cyanates; whose mixtures are +ve Oxidizer include:
Sodium Percarbonate
Potassium Chlorate
Potassium Chromate
Copper Sulfate
Compounds such as copper-CN & chromium-CN give a +ve Oxidizer Test due to the metal HAS NO interferences, no false +ves, no false -ves
Other tests have:
False +ves: Thiocyanates – sodium thiocyanate, potassium thiocyanate, mercury thiocyanate
False -ves: When cyanides are mixed with: bromide, iodide, chromate, permanganate, or strong reducing agent: tin chloride, sodium sulfite, sodium borohydride or zinc metal, a false -ve occurs
More False -ves: Copper cyanide, palladium cyanide, mercuric cyanide & silver cyanide give false -ves
Works in any matrix
If the cyanide is mixed with a paint, the test still works – it looks for hydrogen cyanide gas in the atmosphere above the sample
Other tests rely on color changes to strips of test paper immersed in the sample. If the matrix has a color, this can interfere with reading the test strip
Requires only 1ml of liquid sample or ½ spoonful of solid sample
Other tests require 5ml of liquid sample & do not give instruction for solids
HAZCAT’s reagents do not have a shelf life
Other tests use papers/reagents with expiration dates
 
Hazcat’s Sulfide Test
Not dependent on matrix being tested
Finds H2S gas in the atmosphere above the sample
Gives a positive with a wide range of sulfide types
Will give a +ve with Acid-volatile sulfides:
iron sulfides; FeS, Fe3S4, pyrrhotite, & monosulfides of other metals
Copper & silver sulfides are so insoluble they don’t respond in other test methods
Hazcat’s sulfide test gives a +ve with these substances