Description: Ammonium chloride is used in smoke compositions. When heated ammonium chloride decomposes to HCl and NH3, both gasses. These recombine in the air to give a smoke consisting of fine particles of ammonium chloride.
Hazards: Ammonium chloride based smoke is irritating to the eyes and lungs as it contains some remaining HCl and NH3. Ammonium chloride itself is not poisonous and is even used in some type of candy. But as with all fine powders a dust mask must be worn, and since ammonium chloride is irritating to the skin and damaging to the eyes, gloves and goggles are important. Acording to Shimizu, ammonium chloride forms an exception to the rule that ammonium compounds should not be mixed with chlorates. Due to the lower solubility of potassium chlorate (compared to ammonium chlorate) no ammonium chlorate should form. I personally would still use these mixtures with great caution (or avoid them) since it seems inevitable that small amounts of ammonium chlorate will still form. The lower solubility of potassium chlorate will make it the -main- product in a double decomposition reaction but not the -only- product. It is strongly advised not to mix with metal powders, specifically copper, because it will become extremely corrosive. Toxicity: Oral rat LD50 : 1650 mg/kg Investigated as a mutagen.
Sources: Ammonium chloride solution is easily prepared by neutralising ammonia solution with hydrochloric acid. It is advised to use a slight excess of ammonia. That is to make sure no remaining acid will be present in the ammonium chloride obtained on evaporation and crystallisation. Otherwise traces of the acid solution may be enclosed in the crystals, possibly leading to spontaneous ignition of mixtures made with it.
Hazard Symbols: Xn, Xi