United States
                  Environmental Protection
                       Pesticides And
                       Toxic Substances
September 1991
                  R.E.D.   FACTS
   Use Profile
                  Propionic  Acid
     All pesticides sold or used in the United States must be registered by
EPA, based on scientific studies showing that they can be used without
posing unreasonable risks to people or the environment. Because of
advances in scientific knowledge, the law requires that pesticides which
were first registered years ago be reregistered to ensure that they meet
today's more stringent standards.
     In evaluating pesticides for reregistration, EPA obtains and reviews a
complete set of studies from pesticide producers, showing the human health
and environmental effects of each pesticide. The Agency imposes any
regulatory controls that are needed to effectively manage each pesticide's
risks.  EPA then reregisters pesticides that can be used without posing
undue hazards to human health or the environment.
     When a pesticide is eligible for reregistration, EPA announces this and
explains why in a Reregistration Eligibility Document, or RED. This fact
sheet summarizes the information in the RED for propionic acid.

     Propionic acid is a fungicide and bactericide, registered to control
fungi and bacteria in stored grains, hay, grain storage areas, poultry litter,
and drinking water for livestock and poultry.  It is formulated as a liquid
and sprayed onto grain, hay, grain storage area surfaces, and poultry litter.
It is added directly to drinking water for livestock and poultry.
     Propionic acid is a colorless,  oily, pungent liquid that occurs naturally
in animals and dairy products.  It also is a normal component of metabolism
in the human body.  People consume naturally-occurring propionic acid in
common foods such  as butter and cheese (swiss cheese  may contain as much
as one percent propionic acid),  and as an added ingredient in other foods.

     Propionic acid was first registered as a pesticide in the early 1970's.
In 1975, EPA first exempted propionic acid from certain tolerance, or legal
residue limit, requirements. Currently, two manufacturing-use pesticide
products are registered, as are 12 end-use products, each containing
propionic acid as its sole active ingredient.

Human  Health   Toxicity
  AsS6SSm6nt         Contact with concentrated solutions of propionic acid may cause
                    damage to the eyes, skin and mucous membranes. Since it is corrosive,
                    propionic acid has been placed in Toxicity Category I for acute eye and
                    dermal irritation effects (Toxicity Category I indicating the highest degree
                    of toxicity,  and IV the lowest).  However, propionic  acid is of moderate to
                    low toxicity taken orally or inhaled, and is placed in Toxicity Category III
                    for acute oral, dermal and inhalation effects.
                          Subchronic studies using the related compounds calcium and sodium
                    propionate  showed some adverse effects in the high dose test animals,
                    including lesions of the forestomach, reduced food consumption and growth
                    depression.  However, an adult male human fed sodium propionate showed
                    no effects other than slightly alkaline urine.
                          In a chronic feeding study using propionic acid, the high dose rats had
                    hyperplasia, ulcers and other effects in the forestomach. However, a
                    similar study using calcium and sodium propionate showed no effects other
                    than initial  growth depression.  No maternal, fetal or teratogenic effects
                    have been observed.  Propionic acid is not mutagenic.
                    Dietary Exposure
                          People may be exposed to residues of propionic acid by eating food
                    crops, meat,  milk or poultry.  However, since propionic acid is metabolized
                    by livestock and poultry, any residues in meat, milk  or poultry are
                    negligible.  Further, propionic acid is a normal  metabolite in the human
                    body, and is utilized by most organs and tissues. Therefore, it has been
                    exempt from tolerance, or legal residue limit, requirements when applied to
                    growing crops or raw agricultural commodities  after harvest (40 CFR
                    180.1001 (c)), and when used post-harvest on many grains (40 CFR
                    180.1023).   EPA also intends to exempt residues occurring in livestock or
                    poultry as a result  of application to their drinking water and to poultry litter.
                    Propionic acid  is Generally Recognized as Safe, or GRAS, when used as a
                    direct food additive (21 CFR 184.1081).
                    Applicator Exposure
                          Propionic acid is sprayed on grain, forage, poultry litter and grain
                    storage areas, and is applied directly to livestock and poultry drinking
                    water. Applicators and other workers in spray areas could be significantly
                    exposed. To protect them from eye and skin hazards, the use of protective
                    clothing is necessary.  Appropriate product labeling, as specified in the
                    RED, is being required for product reregistration.

Human Risk Assessment
     Since propionic acid is a normal component of human metabolism,
and is regularly consumed in dairy products and other foods without
consequence, it is not subject to the usual pesticide toxicology data
requirements.  Risks from exposure to propionic acid through the diet are
very low.  Risks from occupational use also are considered low, with the
exception of skin and eye exposure hazards. Therefore, to protect
applicators, the use of protective clothing while applying concentrated
propionic acid products, as specified in the RED, is being required for
product reregistration.

     EPA does not  foresee the potential  for significant environmental risks
associated with the registered uses of propionic acid. All environmental fate
and ecological effects data requirements are waived,  as explained below.
Environmental Fate
     Propionic acid is  registered for  indoor use and limited outdoor use,
only.  Further, in the environment, it acts as a carbon source for various
microbes and is metabolized  to carbon dioxide and water. Therefore, since
propionic acid has little outdoor use, and then is metabolized into simple,
known byproducts, all environmental  fate data requirements are waived.
Ecological Effects
     The available ecotoxicity studies indicate that propionic acid is only
slightly toxic to birds, fish, aquatic invertebrates and mammals. Since it has
limited outdoor use  and low  toxicity, its hazard to nontarget organisms is
expected to be minimal. Therefore, all ecological effects data requirements
are waived.
    Additional Data        While the generic data base for propionic acid is complete, product-
            Required  specific acute toxicity and product chemistry data are  required for
                         reregistration. These requirements are specified in the Data Call-in Notice
                         issued in conjunction with this RED.
  Product Labeling
Changes Required
     The labels of end-use products containing propionic acid must comply
with EPA's current pesticide labeling requirements. In addition,
         Products containing greater than 63% active ingredient must
           include the following protective clothing label requirements:
           "Wear chemical-resistant gloves, chemical-resistant aprons,
           chemical-resistant footwear and goggles or face shield when
           loading application equipment unless a closed loading system is
           used.  Avoid working near high concentrations of spray
           mist/vapor. Use  with adequate ventilation. Wash thoroughly
           after handling."
         Labels of products intended for use on stored grain or hay must
           specify clearly which such crops may be treated, as detailed in
           40CFR 180.1023.

   For More
         Registered pesticide products containing propionic acid  can be
           used without causing unreasonable adverse effects in people or
           the environment. Therefore, they are eligible for reregistration.

         Products containing propionic acid as the sole active ingredient
           will be reregistered once product-specific data and amended
           labeling are received and accepted by EPA.

     EPA is requesting public comments on the Reregistration Eligibility
Document for propionic acid during a 60-day time period, as announced in a
Notice of Availability published in the Federal Register.  To obtain a copy
of the RED or to submit written comments, please contact the Public
Response and Program Resources Branch, Field Operations Division
(7506C), Office of Pesticide Programs (OPP), US EPA, Washington, DC
20460, telephone 703-557-2805.
     In the future, the RED will be available from the National Technical
Information Service (NTIS), 5285 Port Royal Road, Springfield, VA
22161,  telephone 703-487-4650.
     For more information about propionic acid or about EPA's pesticide
reregistration program, please contact the Special Review and Reregistration
Division (7508W), OPP, US EPA, Washington, DC 20460,  telephone 703-
308-8000.  For information about reregistration of individual propionic acid
products, please contact the Registration Division (7505C), OPP, US EPA,
Washington, DC 20460, telephone 703-557-5447.
     For information  about the health effects of pesticides,  or for assistance
in recognizing and managing pesticide poisoning symptoms, please contact
the National Pesticides Telecommunications Network (NPTN).  Call toll-
free 1-800-858-7378, 24 hours a day, seven days a week, or Fax your
inquiry to 806-743-3094.