Ammonium chloride is sold in blocks at hardware stores for use in cleaning the tip of a and can also be included in as . Other uses include a feed supplement for cattle, in hair , in printing, in the glue that bonds , as an ingredient in nutritive media for , in cleaning products, and as . Its action is caused by irritative action on the bronchial mucosa. This causes the production of excess respiratory tract fluid which presumably is easier to cough up.