The plans originally called for production lines to make smokeless powder, diphenylamine, and sulfuric acid. Triphenylamine can be prepared by arylation of diphenylamine. Attempts have been made to explain the color changes associated with the oxidation of diphenylamine. Superficial scald may be controlled by treatment with diphenylamine before storage. Cellulose nitrate can be identified with a chemical spot test using diphenylamine. The EC set maximum residue levels for diphenylamine in 2005. In animal experiments diphenylamine was rapidly and completely absorbed after ingestion by mouth. In this test, a solution of diphenylamine and ammonium chloride in sulfuric acid is used. As additives to rubber, aniline derivatives such as phenylenediamines and diphenylamine, are antioxidants. Thus, acylation of diphenylamine with oxalyl chloride leads to the amide. It consisted of nitrocellulose, dinitrotoluene (DNT), graphite, and a small amount (0.6%) of diphenylamine (stabilizer). Hypochlorous acid gives 4-aminophenol and para-amino diphenylamine. Krupp began adding diphenylamine as a stabilizer in 1888. A diphenylamine (DPA) indicator will confirm the presence of DNA. Diphenylamine can cause severe irritation to the eyes.