Go to your nearest edible supplier. Pick up an apple. What is the powder substance on the sides? It is a pesticide, which slows down produce mold. A popular pesticide is diphenylamine.
(Information origination-
Reregistration Eligibility Decision (RED) document fact sheet case 2210, United States Prevention, Pesticides EPA-738-F-97-010 Environmental Protection And Toxic Substances April 1998 Agency (7508W))
Diphenylamine (DPA) is a plant growth regulator used post-harvest to control storage scald on apples. It is mainly used for its antioxidant properties. As a pesticide, DPA is used for destroying insects or other organisms harmful to cultivated plants. DPA has been classified as an indoor food use.
Storage scald- term loosely applied to a group of skin disorders of apples and pears. It involves brown or gray discoloration of irregularly shaped areas on the surface of the fruit during or following storage (http://postharvest.tfrec.wsu.edu/pages/N6I2C)
Chemical formula- C12H11N
Molar Mass- 169.23 g/mol
Appearance- White, tan, amber, or brown crystals
Odor- pleasant, floral
Density- 1.2 g/cm3
Melting point- 53 °C (127 °F; 326 K)
Boiling point- 302 °C (576 °F; 575 K)
Solubility in water- 0.03%
Vapor pressure- 1 mmHg (108°C)
Acidity (pka)- 0.79
Magnetic susceptibility- -109.7·10−6 cm3/mol
Formulations include an emulsifiable concentrate, a wettable powder, a soluble concentrate/liquid and a ready-to-use liquid. DPA is applied by dipping, drenching or spraying. It was pesticide registered in 1947.
DPA has been shown to be slightly toxic by the oral, dermal, and inhalation routes and has been placed in Toxicity Category III (second lowest of four categories) for these effects. The dietary intake cancer risk for diphenylnitrosamine is 2.8 x 10 mg/kg/day.
DPA is of low acute toxicity and has been classified as “Not Likely“ as a human carcinogen. An impurity of DPA,
diphenylnitrosamine, is classified as a “probable human carcinogen”, however the cancer risks for dietary intake and worker exposure fall below the Agency’s level of concern. Food crop use consist of post-harvest use on apples. Dietary exposure to DPA residues in foods is within acceptable limits.
Since this is considered an indoor food end-use chemical, only hydrolysis data are required. Available data indicate that DPA is stable towards hydrolysis at pH’s 5, 7, and 9. DPA has a moderate solubility in water (39.4 ppm), a relatively high octanol/water partition coefficient (K =3,860), and a high vapor pressure (6.39 x 10 torr). The high rate of ow
-4 aqueous photolysis and the susceptibility of the chemical in aerobic environments indicate that if DPA were to reach surface waters, it would be short lived.
DPA is moderately toxic to fish and aquatic invertebrates. It is practically non-toxic to avian species on an acute and subacute basis.
Industrial handling of Diphenylamine-
The Agency develops any mitigation measures or regulatory controls needed to effectively reduce each pesticide's risks. EPA then reregisters pesticides that meet the safety standard of the FQPA and can be used without posing unreasonable risks to human health or the environment. When a pesticide is eligible for reregistration, EPA explains the basis for its decision in a Reregistration Eligibility Decision (RED) document. These facts are summarized from the RED document for reregistration case 2210, diphenylamine.
