United States
                 Environmental Protection
                      Pesticides And
                      Toxic Substances
June 1991
                 R.E.D.   FACTS
Potassium  Bromide

     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 from
pesticide producers and reviews a complete set of studies 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
     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
potassium bromide.

     In addition to having many other non-pesticidal uses, potassium
bromide is an active ingredient in two registered pesticide products.
The first product, registered since 1960, is a liquid antimicrobial
sanitizer used on food contact surfaces, food handling equipment, and
utensils in food processing and eating establishments. The second
product, registered in  1987, is an algaecide tablet used to control
bacteria and algae in indoor spa water. Both of these pesticide
products are eligible for reregistration.

     Potassium bromide is a well known inorganic chemical whose
chemical and toxicological properties are extensively documented in the
public literature. The non-pesticidal uses of this chemical outweigh the
pesticidal uses, both in number and in economic importance. No
manufacturing use potassium bromide product is registered. Instead,
the technical grade chemical is available as an unregistered material
from chemical supply houses at about 99% purity.

Of Exposure
     Potassium bromide was initially registered for use as a pesticide
(antimicrobial sanitizer) in August 1960.  EPA issued a Registration
Standard for potassium bromide in September 1984,  and required
certain additional data.  In May 1987, the algaecide product was

     All of EPA's generic toxicology data requirements for potassium
bromide have been satisfied.
     The human health effects of potassium bromide are well
understood, and are minimal. Potassium bromide dissolves in water
and breaks  down into potassium and bromide ions. The potassium ion
is present in relatively large amounts in all living organisms and is
essential for life.  The bromide ion is present in small amounts in man and
all other organisms, and has no discernable effect at such low
levels.  The use of bromide salts as tranquilizers for many years has
demonstrated the  low and reversible toxicity of the bromine ion.

Acute Effects
     Potassium bromide is not acutely toxic and it poses a low toxicity
hazard.  Its oral toxicity is well known and is very low.  A high dose
will cause only nausea and vomiting. Similarly, its dermal toxicity is
low, and it  is not a skin  irritant.

Chronic Effects
     EPA has reviewed information in the public literature on
potassium bromide, and finds that it raises no concerns regarding the
chronic or long term toxicology of the approved pesticidal uses.

Through the Diet
     The use of potassium bromide as a sanitizing solution on food-
contact surfaces is considered to be an indirect food additive use.  This
use is regulated and has been approved by the Food and Drug
Administration under the Federal Food, Drug, and Cosmetic Act.
(Please see section 178.1010(b)(l) of 21 CFR.)
     Residues of potassium bromide otherwise are not expected to
occur in food or  feed commodities.  Therefore, no tolerances (legal
residue limits) or exemptions from the requirement of a tolerance have
been established  by EPA, and none  are needed.

                         During Application
                               Due to the low toxicity and registered use patterns of potassium
                         bromide, no occupational or residential exposure data have been
                         required or  are needed.
                                  environmental fate and ecological effects data for potassium
             Hazards  bromide have been reviewed. EPA has sufficient information to conclude
                         that indoor use of potassium bromide will not result in unreasonable adverse
                         effects to humans or the environment.
                         Environmental Fate
                               Because of its use pattern, potassium bromide is not expected to
                         produce any adverse effects in the environment. Therefore, environmental
                         fate data are not required to support reregistration of this pesticide.

                         Ecological Effects
                               The 1984 Registration Standard required the submission of certain
                         ecological effects studies to allow EPA to characterize the toxicity of
                         potassium bromide to birds and fish.
                               Based on the studies submitted, potassium bromide was found to be
                         practically non-toxic to bobwhite quail.  However, it is highly toxic to
                         rainbow trout and  Daphnia magna.  No additional label precautions or use
                         restrictions are being imposed in spite of this finding, however, since the
                         indoor use of potassium bromide is not expected to result in significant
                         exposure to aquatic organisms.

    Additional Data        The generic  data base for potassium bromide has been reviewed and
            R@d UJ r@d  f°und to be complete.  No further generic data are required to support
  Product LabGlinCI        The l^els of end-use products containing potassium bromide must
Chanaes Reauired  comply with EPA's current regulations and requirements. However,  no
                         particular labeling changes are required by the RED.
                                     two registered pesticide products containing potassium bromide
                         can ^e use<^ without causing unreasonable adverse effects in people or the
                         environment.  Therefore, they are eligible for reregistration.
                               * Since both of these products contain other active ingredients in
                         addition to potassium bromide, they will be fully eligible for reregistration

                 only when the other active ingredients also are determined to be eligible.

                      * EPA will reregister the individual products containing potassium
                 bromide once product specific data are submitted to and accepted by the
                 Agency, and when similar information is submitted and accepted in response
                 to the REDs issued for the other active ingredients in these products.

   For MOTG        EPA is requesting public comments on the Reregistration Eligibility
Information   Document for potassium bromide 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, U.S. EPA, Washington, D.C.
                 20460,  telephone 703-557-4436, or Fax #703-557-1884.  Please note that
                 after the comment period closes, the RED will be available from NTIS, at
                 the address and telephone number below.
                      To obtain a copy of the September 1984 Registration Standard for
                 potassium bromide, please contact the National Technical Information
                 Service (NTIS), 5285 Port Royal Road, Springfield, VA. 22161, telephone
                 703-487-4650. Request document #PB89-187256.
                      For more information about potassium bromide,  or about EPA's
                 pesticide reregistration program, please contact the Special Review and
                 Reregistration Division (7508W), Office of Pesticide Programs, U.S. EPA,
                 Washington, D.C. 20460, telephone 703-808-8000, or Fax #703-308-8005.
                      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.