United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-93-025
December 1 993
R.E.D. FACTS
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Mineral Acids
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 for the case mineral
acids, which contains the active ingredients hydrogen chloride, phosphoric
acid, sodium bisulfate, and sulfuric acid.
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The four pesticide active ingredients that comprise the mineral acids
reregistration case are used as tuberculocides, disinfectants, sanitizers,
virucides, fungicides, desiccants and antimicrobials. Hydrogen chloride is
used as a disinfectant for bathroom, commercial, industrial, institutional,
hospital, laboratory, morgue, refuse, cafeteria and veterinary premises, on
surgical instruments, animal cages, swimming pool tile and drinking
fountains, and for dishes, glassware and utensils. Phosphoric acid is used
as an antimicrobial in industrial processing water, empty mushroom houses,
food and dairy premises and processing plant equipment, animal kennels,
hospitals and morgues, and bathroom premises. Sodium bisulfate is used
as a disinfectant for toilet bowls. Sulfuric acid is used as a desiccant on
potato crops, and as a sanitizer for food processing and dairy facilities,
equipment and utensils. Sulfuric acid is the largest volume chemical
produced in the United States, and is used primarily for non-pesticidal
purposes.
These active ingredients are formulated as emulsifiable, soluble and
solid concentrates, ready-to-use liquids, pellets/tablets, solids and
impregnated material.
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Regulatory The mineral acids were first registered as pesticides in the United
History States during the 1950s. Currently, 212 products are registered which
contain the mineral acids as active ingredients.
Human Health
Assessment
Toxicity
All four of the mineral acids are corrosive to the eyes and all except
sodium bisulfate are corrosive to the skin; they have been placed in Toxicity
Category I indicating the greatest degree of acute toxicity for eye and
dermal irritation effects. Sulfuric acid also is extremely acutely toxic by the
inhalation route, and has been placed in Toxicity Category I for inhalation
effects. The mineral acids otherwise are moderately acutely toxic, and are
placed in Toxicity Category III (on a scale of I to IV) for acute oral and
dermal effects. (Sulfuric acid, however, is placed in Toxicity Category II
for acute oral toxicity.)
Dietary Exposure
Sulfuric acid is the only mineral acid that has a registered food use,
that is, application to potato vines five or more days prior to harvest to
desiccate the vines and make harvesting less difficult. Sulfuric acid is
exempt from the requirement of a tolerance for this use. Sulfuric acid was
granted an exemption from tolerance requirements because it is rapidly
degraded in the environment to sulfate salts, which are of no toxicological
concern and are Generally Recognized as Safe (GRAS) by the Food and
Drug Administration. There are no human dietary concerns associated with
the potato vine use of sulfuric acid.
Occupational and Residential Exposure
Hydrogen chloride and phosphoric acid, which are used mainly as
antimicrobials to sanitize food and dairy processing plants, are applied as
wipe-on surface treatments, sprays, and circulate in place (CIP) treatments.
Sodium bisulfate, used as a disinfectant, is a solid soluble concentrate which
is brushed/swabbed onto the interior surfaces of toilet bowls. Sulfuric acid,
like the first two chemicals, is used to sanitize milk lines and food
processing surfaces by wipe-on and CIP treatments. In addition,
concentrated sulfuric acid (93%) is used to desiccate potato vines prior to
harvest. A Restricted Use Pesticide, it is applied by certified applicators
using special ground boom type equipment.
When the four mineral acids are used as antimicrobials, only dilute
solutions are applied to surfaces. Because the chemicals are applied at low
concentrations, mixer/loader/applicator exposure both during and post-
application is likely to be negligible.
The use of concentrated sulfuric acid as a potato vine desiccant may
result in dermal and inhalation exposure of workers, during and after
treatment, potentially causing severe irritation to mucous membranes and
skin. To avoid these effects, product labels must be updated to require
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Environmental
Assessment
adequate personal protective equipment. In addition, the registrant must
explain the basis for the existing 5-day reentry interval, and demonstrate
that it is sufficiently protective to post-application workers.
Human Risk Assessment
The four mineral acids pose no human dietary risks. People may be
exposed to these chemicals when they are used as antimicrobials, however
this exposure involves such dilute solutions that it is believed to be
inconsequential. The use of concentrated sulfuric acid as a potato desiccant
results in high potential for worker exposure and risk. EPA is maintaining
the existing 5-day reentry interval into treated potato fields, and is
requesting a rationale for this interval. In addition, labels must be updated
to require use of adequate personal protective equipment and clothing, as
specified in the Worker Protection Standard.
EPA has predicted the environmental fate of the mineral acids in the
environment using commonly available sources of information, as well as
basic chemistry. The Agency is not able to determine, at this time, if the
use of sulfuric acid as a desiccant on potato vines is eligible for
reregistration. The Agency is concerned about the risk to terrestrial
wildlife, and is not aware of any acceptable methods to mitigate the risk. In
order to determine its eligibility, the Agency will be assessing the benefits
of sulfuric acid for this use. Once this is done, the Agency will make a
finding of whether this use is eligible for reregistration and whether any
further regulatory action is required.
Environmental Fate
The mineral acids generally dissociate and release hydrogen ions in
the environment, thus increasing the pH of soil or water.
Ecological Effects
For all mineral acids and uses except the use of sulfuric acid as a
potato vine desiccant, adequate information is available to predict the effects
on living organisms, so all normally required avian and aquatic studies were
waived. If the mineral acids, diluted or undiluted, came into contact with
birds, they would cause severe dermal toxicity to areas not covered by
feathers. All of the mineral acids pose a potential hazard to the aquatic
environment, due to their ability to change the pH of receiving waters.
Such changes in pH can have serious adverse effects on fish.
Ecological Effects Risk Assessment
Avian species are at risk from direct exposure to mineral acids, and
such exposure must be avoided. Mineral acids also can cause significant
changes in pH, which are harmful to aquatic species and also must be
avoided. These exposures also may be harmful to endangered species. The
risks posed by the mineral acids will be mitigated by product labeling, as
specified in the RED document.
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Additional Data
Red UJ red
Product Labeling
Changes Required
The use of sulfuric acid as a desiccant on potato vines, however, poses
significant hazard to birds and other terrestrial wildlife. Since there are no
known practical mitigation measures, this use is not eligible for
reregistration, at this time.
EPA is requiring product-specific data, including product chemistry
an^ acute toxicity studies, as well as revised Confidential Statements of
Formula (CSF) and revised labeling, for reregistration of products
containing the mineral acids.
All end-use mineral acid products must comply with EPA's current
pesticide labeling requirements. In addition:
° Compliance with Worker Protection Standard (WPS) - Products used
in the production of an agricultural plant or on any agricultural
establishment (farm, forest, nursery or greenhouse) must comply with the
labeling requirements of:
• PR Notice 93-7, "Labeling Revisions Required by the Worker
Protection Standard (WPS) , " and
• PR Notice 93-11, "Supplemental Guidance for PR Notice 93-7."
Unless specifically directed in the RED, all statements required by these two
PR Notices must appear on product labeling exactly as instructed in the
Notices. Labels must be revised by April 21, 1994, for products distributed
or sold by the primary registrant or supplementally registered distributors,
and by October 23, 1995, for products distributed or sold by anyone.
° Personal Protective Equipment and Reentry Requirements - Sulfuric
acid, when used as a potato vine desiccant, has a potential for dermal and
inhalation exposure to mixer/loader/applicators both during and after
application. The current label allows for post- application reentry of
workers when wearing appropriate personal protective clothing and
equipment. Otherwise post-application reentry is not permitted for 5 days.
The posting of notices when fields are treated is required.
° Effluent Discharge Statement - All end-use and manufacturing use
products that may be contained in an effluent discharged to the waters of the
United States must bear the following statement:
"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 the EPA."
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Regulatory
Conclusion
For More
Information
° Wildlife Protection Statement - Products containing hydrogen chloride
or phosphoric acid and used in swimming pools must bear the following
statement:
"This pesticide is toxic to wildlife. Do not contaminate water when
disposing of equipment wash water or rinsate."
The use of currently registered pesticide products containing mineral
acids, except use of sulfuric acid as a desiccant on potato vines, in
accordance with approved labeling will not pose unreasonable risks or
adverse effects to humans or the environment. Therefore, all uses of these
products are eligible for reregistration.
These products will be reregistered once the required product specific
data, revised Confidential Statements of Formula and revised labeling are
received and accepted by EPA. Products which also contain other active
ingredients will be reregistered after the other active ingredients also are
determined to be eligible for reregistration.
The use of sulfuric acid on potato vines will be subject to further
assessment of its benefits for this use. Once this is done, the Agency will
make a finding of whether this use is eligible and whether any further
regulatory action is required.
EPA is requesting public comments on the Reregistration Eligibility
Decision (RED) document for Mineral Acids 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 Mineral Acids 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 EPA's pesticide reregistration program,
the Mineral Acids RED, or reregistration of individual products containing
mineral acids, please 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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