Solutions of diphenylamine are used to treat apples a few days
before harvest. Residue on apples’ surfaces of 10 ppm is
permitted by regulation in Australia, Canada, and the United
States.
Diphenylamine is a colorless monoclinic leafl et substance. It is used in the manufacture
of a variety of substances, i.e., dyestuffs and their intermediates, pesticides, antihelmintic
drugs, and as reagents in analytical chemistry laboratories.
Diphenylamine is used post-harvest to prevent superficial scald in
apples in cold store.
Diphenylamine is used in the manufactureof dyes, as a stabilizer for nitrocelluloseexplosives, and as an analytical reagent forcolorimetric tests for nitrate and chlorate.
Other applications of this compoundinclude preventing postharvest deteriorationof apple and peer crops; as an antioxidant inrubber and elastomer industry and in the per fumery. As a stabilizer for propellants andexplosives, it binds their degradation prod ucts thus prolonging the storage time of suchpropellants.
Diphenylamine is an aromatic amine that was shown to exhibit antioxidant activities and is now used as an anti-scald agent. It is also used in the manufacture of a variety of substances, for instance, dye stuffs and their intermediates, pesticides, anthelmintic drugs, and as reagents in analytical chemistry laboratories.
ChEBI: An aromatic amine containing two phenyl substituents. It has been used as a fungicide for the treatment of superficial scald in apples and pears, but is no longer approved for this purpose within the European Union.
diphenylamine: A colourless crystallinearomatic compound,(C6H5)2NH; m.p. 54°C. It is made byheating phenylamine (aniline) withphenylamine hydrochloride. It is asecondary amine and is both slightlyacidic (forming an N-potassium salt)and slightly basic (forming salts withmineral acids). Its derivatives are employedas stabilizers for syntheticrubber and rocket fuels.
Light tan to brown solid with a pleasant odor. Sinks in water.
Dust may be explosive if mixed with air in critical proportions and in the presence of a source of ignition [USCG, 1999]. Insoluble in water.
Diphenylamine discolors in light. Diphenylamine can react violently with hexachloromelamine and trichloromelamine. Diphenylamine is incompatible with strong oxidizing agents and strong acids. Diphenylamine is also incompatible with iron and silver salts. Diphenylamine reacts with nitrogen oxides.
Inhalation may irritate mucous membranes. Overexposure, including ingestion of solid or skin contact, may cause fast pulse, hypertension, and bladder trouble. Contact with dust irritates eyes.
Diphenylamine is much less toxic than aniline. The acute oral toxicity is low. A doseof 3000 mg/kg was lethal to rats. At a concentration of >500 ppm, a diet fed to ratsfor over 7 months resulted in renal cysts inanimals. Its absorption through the skin andthe respiratory system is lower than that ofaniline. Exposure to its dusts caused changesin liver, spleen, and kidney in test animals.Industrial exposure to diphenylamine hascaused tachycardia, hypertension, eczema,and bladder symptoms in workers (Fairhall1957). Carcinogenicity of this compound isunknown. It showed an adverse reproduc tive effect in animals, causing developmentalabnormalities in urogenital system in pregnant rats.
LD50 value, oral guinea pig: 300 mg/kg.
Diphenylamine is highly toxic and is rapidly absorbed by the skin and through inhalation.
It has caused anorexia, hypertension, eczema, and bladder symptoms. Experimental
animals exposed to diphenylamine demonstrated cystic lesions but failed to demonstrate
cancerous growth. Inhalation of diphenylamine dust may cause systemic poisoning. The
symptoms of toxicity include, but are not limited to, anoxia, headache, fatigue, anorexia,
cyanosis, vomiting, diarrhea, emaciation, hypothermia, bladder irritation, kidney, heart,
and liver damage.
Noncombustible solid; autoignition temperature 634°C (1173°F); low reactivity.
Flammability and Explosibility
Non flammable
Insecticide, Fungicide, Herbicide, Plant growth
regulator: Topically in anti-screwworm mixtures, foliar application in a modified growth chamber to decrease ozone injury to
leaves of apple, bean, muskmelon, petunia, and tobacco plants.
To control weather fleck in tobacco and inhibit algae formation. To prolong the fresh appearance of snapdragons. Protect
rice from the toxic effects of thiolcarbamate herbicides [83] . Not
currently approved for use in EU countries (resubmitted) .
Registered for use in the U.S. and other countries.
NOSCALD DPA 31; NOSCALD DPA
283; SCALDIP; Z-876
Poison by ingestion.
Experimental teratogenic effects. Action
similar to anhne but less severe.
Combustible when exposed to heat or
flame. Can react violently with
hexachloromelamine or trichloromelamine.
Can react with oxilzing materials. To fight
fire, use CO2, dry chemical. When heated to
decomposition it emits highly toxic fumes of
NOx,. See also ANILINE, AMINES, and
AROMATIC AMINES.
AgriculturalChemical; Mutagen; Reproductive Effector. DPA is used asa stabilizer for plastics including solid rocket propellants;antioxidant for polymers, greases, and industrial oils; in themanufacture of pharmaceuticals; pesticides, explosives, anddyes.
If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.Medical observation is recommended.
Diphenylamine is present in waste water from industrial
processes. Diphenylamine has been detected in milk of
animals (cow, sheep, goat, water buffalo) raised in Italy and
France.
Pseudokirchneriella subcapitata (Algae) growth was inhibited
with a dose of 0.30 mg l-1. Aquatic invertebrates Daphnia
magna showed an acute 48 h EC50 dose of 1.2 mg l-1.
The major metabolite of diphenylamine (DPA)
identified in stored apples is a glucose conjugate of
4-hydroxydiphenylamine, and additional metabolites,
characterized as glycosyl conjugates of 2-hydroxy-
DPA, 3-hydroxy-DPA, 4-hydroxy-DPA, or dihydroxy-
DPA, are also detected along with their intact (i.e.
non-conjugated) forms in apple pulp.
Diphenylamine should be protected from physical damage. Storage of diphenylamine
outside or a detached area is preferred. Inside storage should be in a standard flammable
liquids storage room or cabinet. Diphenylamine should be kept separately from oxidizing
materials and incompatible chemical substances. Storage and work areas should be no
smoking areas. Diphenylamine should be kept protected from light.
Toxic solids, flammable, organic, n.o.s. requiresa shipping label of “POISONOUS/TOXIC MATERIALS.”It falls into Hazard Class 6.1.
Crystallise diphenylamine from pet ether, MeOH, or EtOH/water. Dry it under vacuum. [Beilstein 12 H 174, 12 IV 271.]
Diphenylamine is an anti-oxidant and therefore reacts with oxygen under
conditions of use. It darkens on exposure to sunlight. Aqueous photolysis
is pH and oxygen dependant (Lopez et al., 1980). It is converted into
carbazole (2) and hydrogen peroxide in the presence of dissolved oxygen.
In degassed solution it is converted into carbazole (2) and tetrahydrocarbazole
(3) (see Scheme 1).
Dust may form an explosive mixturewith air. Incompatible with strong acids, strong oxidizers,aldehydes, organic anhydrides, isocyanates, hexachloromelamine, trichloromelamine. Reacts with nitrogen oxidesforming n-nitrosodiphenylamine and heat-, friction-, andshock-sensitive nitro products
Students and occupational workers should be careful during use and handling of diphenylamine.
Workers should wear impervious protective clothing, including boots, gloves,
a laboratory coat, apron or coveralls, as appropriate, to prevent skin contact. Finely dispersed
particles of diphenylamine form explosive mixtures in air. Diphenylamine is very
harmful on exposures by swallowing, inhalation, and/or skin absorption. Diphenylamine
causes irritation to the skin, eyes, and respiratory tract, and causes blood vascular changes
leading to methemoglobinemia.
