United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-93-018
December 1993
R.E.D. FACTS
Pesticide
Reregistration
Lithium Hypochlorite
All pesticides sold or distributed 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, 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 unreasonable risks to human health or the environment.
When a pesticide is eligible for reregistration, EPA announces this and
explains why in a Reregistration Eligibility Decision (RED) document. This
fact sheet summarizes the information in the RED document for lithium
hypochlorite.
Use Profile
Lithium hypochlorite is an algicide, disinfectant, fungicide and food
contact surface sanitizer. Its primary pesticidal use is to control algae,
bacteria and mildew in swimming pool water systems, hot tubs and spas;
approximately 2,000,000 pounds of the active ingredient were used for this
purpose in 1989. It also is used to sanitize food and cheese processing plant
equipment, dairies, and eating establishment equipment and utensils.
Lithium hypochlorite is formulated as a ready-to-use liquid and a soluble
solid concentrate. It is applied to swimming pool water using a skimmer
basket, and to equipment or utensils by hand or through use of a dish
washing machine. Lithium is an element that occurs naturally at low levels
in food and drinking water.
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Regulatory
History
Human Health
Assessment
Lithium hypochlorite was first registered in the U.S. in 1963, and has
been used chiefly as a sanitizer in swimming pools. The Food and Drug
Administration (FDA) lists the chemical as a sanitizer on food contact
surfaces (please see 21 CFR 178.1010). EPA's Office of Water regulates
discharges into water systems through the National Pollutant Discharge
Elimination System (NPDES) permit program.
EPA issued a Data Call-In (DCI) Notice in September 1992 requiring
product chemistry and ecological effects data for lithium hypochlorite.
Currently, 40 pesticide products are registered which contain this active
ingredient, and no new uses are pending.
Toxicity
In laboratory animal studies, technical grade lithium hypochlorite has
been shown to be highly corrosive, placing it in Toxicity Category I
(indicating the highest degree of acute toxicity) for both eye and skin
irritation. It is moderately acutely toxic in acute oral and dermal toxicity
studies, placing it in Toxicity Category III for oral toxicity and Toxicity
Category IV for dermal toxicity. No mutagenic effects were seen in a
battery of studies.
Studies on human use of lithium-containing drugs, including chronic
use, have not shown any reason for concern over continued human exposure
to lithium following its use as a pesticide. The medicinal exposures are at a
much higher level than that which results from the compound's pesticide
uses. Studies of people who swam in pools or bathed in spas treated with
lithium hypochlorite/ chloride show no significant absorption of lithium
through human skin. Accidentally swallowing pool or spa water should not
increase exposure to lithium beyond that which occurs ordinarily through
ingesting food and drink.
Dietary Exposure
No dietary exposure is expected from the pesticide uses of lithium
hypochlorite since no food or feed uses are registered.
Occupational and Residential Exposure
During application of pesticide products that contain lithium
hypochlorite, workers may experience dermal and inhalation exposure (for
example, while hand-washing utensils). However, this exposure does not
pose significant concerns except to the eye and skin of workers who handle
concentrated or solid formulations. Appropriate label precautions requiring
eye and skin protection will continue to mitigate these risks. Post-
application exposure is considered minimal, as the exposure is to a diluted
material.
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Environmental
Assessment
Human Risk Assessment
Since lithium hypochlorite has no food or feed uses, dietary risk is not
expected. The chemical causes severe irritation and is corrosive to eyes and
skin, but exhibits only moderate acute oral and dermal toxicity. To protect
applicators' eyes and skin, appropriate label precautions regarding use of
protective clothing (including safety glasses or goggles and chemical-
resistant gloves) continue to be required. No human health risk of concern
is expected.
Environmental Fate
Lithium hypochlorite, like all the hypochlorite salts, forms
hypochlorous acid when dissolved in water; it is hypochlorous acid that
exhibits actual pesticidal activity. Its mode of action is its oxidizing
(sanitizing) effect on organic and inorganic contaminants. This disinfection
by chlorination is achieved by maintaining a "free residual chlorine"
concentration.
The major environmental/ecological concern would be if discharged
effluent treated with hypochlorites showed free residual chlorine
concentrations that exceeded those stipulated under NPDES permits. Since
there are many forms of cations used to form hypochlorite salts (e.g.,
calcium, sodium, and lithium), it would be difficult to trace the source of
contamination in cases where free residual chlorine concentrations are too
high.
EPA conducted a Tier Ic Estimated Environmental Concentration
(EEC) model to assess the residue levels of lithium hypochlorite in the
receiving stream from several use sites. This model provides a reasonable
worst case estimate of the maximum concentrations that may occur
immediately downstream from an industrial point source discharge site
under typical and high exposure scenarios. Results are discussed below.
Ecological Effects
Lithium hypochlorite is considered slightly toxic to nontoxic to avian
species, and it is not expected to be found in the environment at levels of
concern. Therefore, risk to avian species is expected to be minimal.
Toxicity to fish and aquatic invertebrates, however, is considered very high.
Ecological Effects Risk Assessment
The results of the Tier Ic EEC stream flow screening model described
above show that levels of concern would be exceeded during both high
exposure and typical exposure scenarios for fish and aquatic invertebrates.
Therefore, aquatic organisms may be at risk from typical use/exposure as
well as from high use/exposure.
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The discharge of water containing residues of lithium hypochlorite is
regulated by the NPDES permit program administered by EPA. Exposure
and risk to freshwater aquatic organisms should be considered in
determining acceptable levels for such permits so that toxic levels are
avoided.
Endangered Species
Both the typical and the high exposure scenarios described above
exceed the levels of concern for endangered aquatic organisms. Effluent
containing lithium hypochlorite should not be discharged into streams or
waterways that endangered aquatic organisms are known to frequent. EPA
is working with the U.S. Fish and Wildlife Service to develop a program to
avoid jeopardizing the continued existence of identified species by the use of
pesticides. When this program goes into effect, endangered species labeling
will be required.
Additional Data The generic data base for lithium hypochlorite is substantially
Red UJ r0d complete. The Agency is requiring product-specific data, including product
Product LabGling
ChanCieS RGCIUirGd
chemistry and acute toxicity studies, as well as revised Confidential
Statements of Formula (CSF) and revised labeling for reregistration.
All end-use products containing lithium hypochlorite must comply
EPA' s current pesticide product labeling requirements. In addition:
• Effluent Discharge Statement - All end-use (and manufacturing use)
products that may be contained in an effluent discharged to the waters of the
U.S. or municipal sewer systems must bear the following statement:
"This product is toxic to fish. Do not discharge effluent containing
this product into lakes, streams, ponds, estuaries, oceans or other
waters unless in accordance with the requirements of a National
Pollutant Discharge Elimination System (NPDES) permit and the
permitting authority has been notified in writing prior to discharge.
Do not discharge effluent containing this product to sewer systems
without previously notifying the local sewage treatment plant
authority. For guidance contact your State Water Board or Regional
Office of EPA."
Regulatory
Conclusion
The currently registered uses of lithium hypochlorite could pose risks
to aquatic organisms under certain conditions as industrial effluent
containing the parent chemical is released into receiving waters. However,
the uses will not cause unreasonable adverse effects to humans or the
environment, and are eligible for reregistration.
Products containing lithium hypochlorite as the sole active ingredient
will be reregistered once the required product-specific data, CSF and
revised labeling are received and accepted by EPA. Products also
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For More
Information
containing other active ingredients will be reregistered only after the other
active ingredients also are determined to be eligible for reregistration.
EPA is requesting public comments on the Reregistration Eligibility
Decision (RED) document for lithium hypochlorite 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 document 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 lithium hypochlorite RED
document 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 EPA's pesticide reregistration program,
the lithium hypochlorite RED, or reregistration of individual products
containing lithium hypochlorite, contact the Special Review and
Reregistration Division (7508W), OPP, US EPA, Washington, DC 20460,
telephone 703-308-8000.
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, between 8:00 am and 6:00 pm Central Time, Monday
through Friday.
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