United States
Environmental Protection
Agency
Office of Prevention, Pesticides
And Toxic Substances December
(7508W)
EPA-738-F-93-023
1993
R.E.D. FACTS
Pesticide
Reregstration
Bromine
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 reregi strati on, EPA obtains and reviews a
complete set of studies from pesticide producers, describing 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 reregi strati on, EPA announces this and
explains why in a Reregi strati on Eligibility Decision Document, or RED.
This fact sheet summarizes the information in the RED for bromine.
Use Profile
Regulatory
History
Bromine is registered for use in water filters to purify drinking water
aboard U. S. Naval ships and offshore oil well platforms. It also is used as a
general disinfectant and sanitizer in indoor, non-food contact areas such as
commercial establishments, hospitals and households, to control bacteria and
fungi. Bromine pesticide products may be formulated as a solid soluble
concentrate or ready-to-use liquid. They are applied using a water filter
unit, drip dispenser, automated metering system, fogger, or hand held or
power sprayer.
Bromine was first registered in May of 1976 for use in treating
potable water through a polybrominated ion exchange resin aboard Naval
surface ships. A food additive tolerance for 1.0 ppm residual bromine in
potable water aboard Naval surface ships was established in April 1976 by
the Environmental Protection Agency. Bromide ion levels in potable water
were exempted from the requirement of a tolerance. (40 CFR § 185.425).
Toxicity
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Human Health
Assessment
In water and living organisms, bromine reacts with other compounds
to form bromides. A great deal of information is available in the literature
on bromides, which have long been used as human drugs (primarily as oral
sedatives, diuretics and anti-epileptic treatments). Their human health
effects are well known. Bromides depress the central nervous system when
taken daily at a level of 1 to 2 grams per day. The effect is slowly reversed
when dosing is stopped. Bromide has a half-life of about 12 days in the
human body.
The levels of bromides consumed as drugs are far greater than the
amounts that are ingested from the registered water purification uses. A
moderate dose to treat epilepsy would be 50 milligrams per kilogram
(mg/kg) per day. By comparison, ingestion of water treated with the
bromine water filter unit results in consumption of no more than
approximately 0.03 mg/kg/day from water containing up to 1 ppm available
bromine for a 70 kg adult.
The lowest level of oral exposure known to result in bromide
intoxication was 100 mg/dl (milligrams per deciliter), but signs of such
effects may not occur even when blood levels are over 200 mg/dl. Most
people develop signs of bromide intoxication at blood levels between 200
and 300 mg/dl.
Doses of 1.9 to 2.9 grams per day given to patients over a four month
period did not induce signs of bromide intoxication. However, tremendous
variation in responses among patients was noted. Acute overdoses in
humans have produced vomiting or stupor, while chronic use has caused
depression, loss of muscle coordination and psychoses. Two cases of
human reproductive effects have been reported.
Based on acute toxicity studies using laboratory animals, sodium
bromide has been placed in Toxicity Category III for acute oral and acute
dermal effects, and in Toxicity Category IV (indicating the lowest level of
acute toxicity) for eye and skin irritation. Sodium bromide is nonsensitizing
to skin.
In subchronic feeding studies, at the highest dose level, effects on rats
included lack of grooming, motor incoordination, growth retardation and
thyroid inaction. In a chronic toxicity study using dogs, at the highest dose
level, signs of bromide intoxication were seen. Pregnant rats fed bromide
produced offspring with reduced learning ability.
In addition to bromide, bromate may form as a by-product under some
conditions. The Agency believes there is sufficient and clear evidence that
chronic oral exposure to bromate causes increased renal tumors in rats.
Based on information from several studies and the incidence of renal
tumors in male rats, the Agency has assigned the bromate ion a Group B2
(probable human carcinogen) classification. A low dose linearized
extrapolation model was used to quantitatively characterize risk for humans.
A Qj* of 4.9 x 10"1 (mg/kg/day)"1 for the potassium bromate was derived
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from the combined renal adenoma and adenocarcinoma data (Kurokowa et
al., 1986a). It is expected that other soluble salts of bromate are equally
carcinogenic. Adjusting for the molecular weight, the unit risk for the
bromate ion is calculated to be 6.5 x 10"1 (mg/kg/day)"1.
Dietary Exposure
People may consume small amounts of bromine residues in treated
drinking water aboard Navy ships or on oil well drilling platforms.
However, adequate controls are in effect to ensure that residues will not
exceed 1.0 ppm, the food additive tolerance level established for bromine in
potable water (please see 40 CFR 185.425). EPA has reassessed this
tolerance and found that it is set at an appropriate level and provides an
adequate margin of safety to protect the public health.
However, there are no data on the amount of bromate, a species of
potential concern. In the absence of actual data on the magnitude of
bromate ion in potable water generated via bromination, the Agency
attempted to determine the likelihood of the presence of bromate ion based
on theoretical considerations. Information obtained from registrants, a
bromine producer, other EPA offices, the bromine test kit manufacturer, a
halogen chemist, and both medical and engineering specialists within the
Navy Dept. indicate that when at port, virtually all potable water is obtained
from an approved water source, and bromination is not necessary as such
water has already been chlorinated. Virtually all (99%) brominated potable
water used on board naval vessels has been derived via desalination using
distillation. The pH of distilled water is known generally to be close to 6.
Also, the "total available bromine" (TAB) concentrations in the potable
water are initially < 2 ppm (usually much less) but that the typical (and
required) concentration is about 0.2 ppm in water after exposure to bromine
for 30 min. The concentration of bromate ion in water cannot be calculated
because the kinetics of bromine disproportionation have not been elucidated
as they have for chlorine and iodine. However, the Agency expects that
bromate ion would be nondetectable (< 0.5 ppb) in water of pH 5-6.
The available information does not allow the Agency to calculate the
bromate ion concentration in potable water. A concentration of
approximately 0.7 ppb bromate ion in water would correspond to a risk of 1
x 10"6 assuming 1.2 liters of water consumed per day and that ship personnel
would be exposed for 6 months a year for 7 years, a typical exposure based
on information provided by the Navy. If bromate ion were present at 0.7
ppb in water, this would represent 0.035% of the total bromine if the water
had been treated with bromine at 2 ppm. (For comparison, a risk of 1 x 10"
6 would correspond to a daily exposure of 0.054 ppb bromate ion in
drinking water, over a 70-year lifetime.)
Because there is not enough information to permit the Agency to
estimate the dietary exposure to bromate ion via potable water aboard Navy
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vessels, the Agency has required representative monitoring data for the pH
and bromate ion concentration of brominated, desalinated water.
Occupational and Residential Exposure
EPA is not concerned with potential human exposure from the surface
sanitizer uses of bromine. The active ingredient in sanitizer products is
present as bromide, and exposure to only very small amounts, below the
level of toxicological concern, is expected. For large volume applications
such as fogging, product labels instruct users to wear protective clothing,
gloves and a respirator, to adequately ventilate spaces treated, and to avoid
reentry of treated spaces for at least one hour after treatment.
Human Risk Assessment
Human health risks from exposure to bromine residues in potable
drinking water are expected to be minimal because water must be tested to
ensure that residues are at a sufficiently low level prior to consumption, and
since the principal residue in water purification systems is bromide rather
than bromine.
The two surface sanitizer products have a very low bromide content
(0.04%). The potential for human exposure to bromide in these products is
low and will not pose an unacceptable risk to humans, provided that current
end-use product labeling which requires Personal Protective Equipment
(gloves, protective clothing and respirator for large volume applications)
and reentry restrictions is maintained.
Environmental
Assessment
Environmental Fate
Bromine is a naturally occurring element that normally is found as
bromide in living organisms and the environment. It is a common
component in seawater and volcanic rocks.
The current use patterns of pesticide products containing bromine do
not result in environmental exposure. Therefore, the RED includes no
discussion of bromine's environmental fate.
Ecological Effects and Risk Assessment
Since bromine is only used indoors, EPA did not prepare an
ecological effects risk assessment. Only two studies were required (a fish
acute and an aquatic invertebrate acute study). These studies were used to
determine the environmental hazard statement for labeling. These data show
that bromine is highly toxic to freshwater fish and aquatic invertebrates.
Additional Data
Required
The generic data base for bromine is substantially complete. The
Agency is requiring product-specific data, including product chemistry,
acute toxicity and efficacy studies, as well as revised Confidential
Statements of Formula and revised labeling, for reregi strati on of pesticide
products containing bromine.
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Product Labeling
Changes Required
Regulatory
Conclusion
For More
Information
The labels of all registered pesticide products containing bromine must
comply with EPA's current pesticide labeling requirements.
All end-use bromine products must comply with EPA's current
pesticide product labeling requirements. In addition, since bromine is
highly toxic to aquatic organisms, end-use labels must contain the following
statement:
"This pesticide is toxic to fish and aquatic invertebrates."
The use of currently registered pesticide products containing bromine
as labeled and specified in the RED document will not pose unreasonable
risks or adverse effects to humans or the environment. Therefore, all uses
of these products are eligible for reregi strati on.
These bromine products may be reregistered, if all active ingredients
in the product are eligible, once the product-specific data, revised
Confidential Statements of Formula and revised labeling are received and
accepted by EPA.
EPA is requesting public comments on the Reregi strati on Eligibility
Decision Document (RED) for bromine 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
Pesticide Docket, Public Response and Program Resources Branch, Field
Operations Division (7506C), Office of Pesticide Programs (OPP), US
EPA, Washington, DC 20460, telephone 703-305-5805.
Following the comment period, the bromine 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 bromine or about EPA's pesticide
reregi strati on program, please contact the Special Review and Reregi strati on
Division (7508W), OPP, US EPA, Washington, DC 20460, telephone 703-
308-8000. For information about reregi strati on of individual products
containing bromine, please contact Frank Rubis, Product Reregi strati on
Branch (7508W), OPP, US EPA, Washington, DC 20460, telephone 703-
308-8184.
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