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Since ammonia exists naturally and is also present in cleaning products , exposure may occur from these sources . Because of the risk of compaction and a high likelihood of ammonia loss ( due to poor soil coverage after application ) , the best strategy for nitrogen application is to wait until conditions are workable to avoid soil damage and significant nitrogen loss . Recent improvements in sewage treatment have decreased ammonia concentrations downstream from many urban areas by converting the ammonia to nitrate . In the old days , sulfur dioxide and ammonia were okay if they stayed in a refrigerator loop , but when that leaked they had an odor you did n't want in your kitchen . Estes also sold anhydrous ammonia as a fertilizer .