United States
Environmental Protection
Agency
Pesticides And
Toxic Substances
(7508W)
738-F-91-108
September 1991
R.E.D. FACTS
Pesticide
Reregistration
Use Profile
Regulatory
History
Sodium and Calcium
Hypochlorite Salts
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 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 sodium and calcium
hypochlorite salts.
Sodium and calcium hypochlorite are chlorinated inorganic disinfectants
used in laundries, swimming pools, ponds, drinking water, and other water and
wastewater systems; on food and non-food contact surfaces; and as a
postharvest, seed or soil treatment on various fruit and vegetable crops. The
hypochlorites control bacteria, fungi, and slime-forming algae that can cause
diseases in people and animals.
Sodium and calcium hypochlorite, better known as bleach, are widely
used compounds whose chemical and toxicological properties are extensively
documented in published literature. These chemicals were first registered for
use as pesticides in 1957.
EPA issued a Registration Standard for sodium and calcium
hypochlorite in February 1986. The Agency concluded that no additional
scientific data would be necessary to register or reregister products that
contain sodium hypochlorite from 5.25% to 12.5%, or calcium hypochlorite
from 65% to 70%, as long as the products contain no other active
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ingredients, contain no inert ingredients other than water, and bear Toxicity
Category I labeling. EPA still supports these basic findings.
Human Health Toxicity
Assessment All toxicology data requirements for sodium and calcium hypochlorite
were satisfied when the Registration Standard was issued in 1986. No
additional health effects data are required.
Sodium and calcium hypochlorite are extremely corrosive and can cause
severe damage to the eyes and skin. They have been assigned to Toxicity
Category I, indicating the highest degree of toxicity, for these acute effects.
No subchronic or chronic studies on sodium and calcium hypochlorite are
needed, due to their simple chemical nature and structure. In the presence of
oxygen, these compounds react easily with organic matter and convert readily
into sodium chloride (table salt) and calcium chloride (road salt). Widely used
in disinfecting water supplies for nearly a century, the hypochlorites have been
proven safe and practical to use.
One concern with the use of sodium and calcium hypochlorite in treating
water and waste water systems is that they may result in the formation of
trihalomethanes in drinking water. Several trihalomethanes are considered
potential carcinogens. However, EPA's Office of Drinking Water has
addressed this potential risk by setting a Maximum Contaminant Level of 100
parts per billion (ppb) for trihalomethanes in drinking water. Using this
standard, public water supply systems will be able to maintain levels of
trihalomethanes within acceptable limits.
Dietary Exposure
Residues of sodium and calcium hypochlorite may remain on certain food
crops as a result of their disinfectant uses. However, these residues pose no
known hazard to human health.
Preharvest and postharvest uses of calcium hypochlorite on all
agricultural commodities are exempted from the requirement of a tolerance, or
legal residue limit, because they pose no known hazard to the public health
(please see 40 CFR 180.1054). Similarly, EPA will propose to exempt crop
uses of sodium hypochlorite from tolerance requirements. (Sodium
hypochlorite is among those few substances "generally recognized as safe," or
GRAS. Please see 40 CFR 180.2.)
Food additive regulations are established for several food processing uses
of the hypochlorites. Sodium hypochlorite may be used in washing and lye
peeling of fruits and vegetables (please see 21 CFR 173.315). Sodium or
calcium hypochlorite may be used as a final sanitizing rinse on food processing
equipment (see 21 CFR 178.1010).
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The 1986 Registration Standard required that food additive tolerances be
obtained for calcium hypochlorite in sugar syrup and raw sugar; however,
these additional tolerances were not obtained. Registrants now must delete
these uses from the appropriate calcium as well as sodium hypochlorite labeling
within eight months or face enforcement action.
Other Routes of Exposure
The use of protective clothing, including safety glasses or goggles and
chemical-resistant gloves, is still required while handling and applying products
that contain sodium or calcium hypochlorite as the active ingredient, due to the
acute toxicity of these products.
In addition, reentry levels must be met before entering swimming pools
or hot tubs/spas treated with sodium or calcium hypochlorite, and reentry
intervals must be observed before using sprayed or fogged food and non-food
contact surfaces.
Human Risk Assessment
Based on the toxicity profile and exposure scenarios for calcium and
sodium hypochlorite, EPA concludes that the risks from chronic and
subchronic exposure to low levels of these pesticides are minimal and without
consequence to human health. Acute exposure to high concentrations can cause
eye and skin injury. However, these risks are mitigated by precautionary
labeling that requires protection of eyes and skin while using these pesticides.
Environmental All environmental fate and ecological effects data requirements for
Assessment sodium and calcium hypochlorite have been satisfied since the Registration
Standard was issued in 1986. Upon reevaluating these date, EPA has
concluded that the currently registered uses of the hypochlorites will not result
in unreasonable adverse effects to the environment.
Environmental Fate
The environmental fate data requirements for the hypochlorite salts are
primarily satisfied by the document, Ambient Water Quality Criteria for
Chlorine, by J. Tobler, et. al., U.S. EPA, June 1981.
In fresh water, the hypochlorites break down rapidly into non-toxic
compounds when exposed to sunlight. In seawater, chlorine levels decline
rapidly; however, hypobromite (which is acutely toxic to aquatic organisms)
is formed. EPA believes that the risk of acute exposure to aquatic organisms
is sufficiently mitigated by precautionary labeling and National Pollutant
Discharge Elimination System (NPDES) permit requirements.
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Additional Data
Required
Product Labeling
Changes Required
Ecological Effects
Sodium and calcium hypochlorite are low in toxicity to avian wildlife,
but they are highly toxic to freshwater fish and invertebrates. However, uses
that result in point source discharges of hypochlorite-containing effluents are
regulated through issuance of site-specific NPDES permits. This program
ensures that the amount of hypochlorites discharged at each site will not pose
significant adverse effects on non-target organisms.
The generic data base for sodium and calcium hypochlorite has been
reviewed and found to be complete for reregistration.
EPA has adequate product-specific data for products that meet the criteria
of the 1986 Registration Standard, and is requiring no further data for their
reregistration.
Product-specific data are required only for pesticide products containing
sodium or calcium hypochlorite that do not meet the criteria of the 1986
Registration Standard, that is,
- products with a percent of active or inert ingredients that fall outside
the ranges specified by the Standard;
- products with inert ingredients other than water; and
- products containing additional active ingredients (mixtures).
The labels of end-use products containing sodium or calcium hypochlorite
must be amended as follows:
E Any product label that currently allows both end use and
manufacturing use must be amended to specify only one use or the other.
E Because they have the potential to cause serious eye and skin damage
if accidentally spilled, all products assigned to Toxicity Category I due to eye
and/or skin effects must bear the Statement of Practical Treatment on the front
panel. They also must continue to require use of protective clothing during
application.
E The "If Swallowed" statement must say: "IF SWALLOWED, drink
large amounts of water. DO NOT induce vomiting. Call a physician or poison
control center immediately."
E Since food additive tolerances were not established as previously
required, the sugar syrup and raw sugar uses of sodium and calcium
hypochlorite must be deleted from product labeling within eight months or
EPA will initiate appropriate enforcement action.
E To protect aquatic life, products with uses that result in
discharge into the aquatic environment must include a statement on the
label indicating that the product is toxic to fish and aquatic organisms.
They also must bear a statement prohibiting discharge of effluent
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containing the product into bodies of water, without an National Pollutant
Discharge Elimination System (NPDES) permit.
Regulatory
Conclusion
For More
Information
E All pesticide products containing sodium and calcium hypochlorite are
eligible for reregistration, except calcium hypochlorite products used on sugar
syrup and raw sugar. Since the required food additive tolerances were not
obtained, these uses now must be deleted from product labeling.
E Products that meet the criteria of the 1986 Registration Standard will
be reregistered when revised labeling and confidential statements of formula
are received and accepted by EPA.
E Products that do not meet the criteria of the 1986 Registration
Standard will be reregistered only when product-specific data, revised labeling
and confidential statements of formula are received and accepted by EPA.
EPA is requesting public comments on the Reregistration Eligibility
Document for sodium and calcium hypochlorite salts 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), U.S. EPA,
Washington, D.C. 20460, telephone 703-557-2805. Please note that in the
future, the RED will be available from NTIS, at the address and telephone
number below.
To obtain a copy of the February 1986 Registration Standard for sodium
and calcium hypochlorite salts, please contact the National Technical
Information Service (NTIS), 5285 Port Royal Road, Springfield, VA. 22161,
telephone 703-487-4650. Request document #PB87-103222.
For more information about sodium and calcium hypochlorite, or about
EPA's pesticide reregistration program, please contact the Special Review and
Reregistration Division (7508W), OPP, U.S. EPA, Washington, D.C. 20460,
telephone 703-308-8000. For information about reregistration of individual
hypochlorite products, please contact the Registration Division (7505C), OPP,
U.S. EPA, Washington, D.C. 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.
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