Tolerance Exemptions: Residues of Silver in Foods from Food Contact Surface Sanitizing Solutions

Federal Register: June 10, 2009 (Volume 74, Number 110)

Rules and Regulations

Page 27447-27454

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

DOCID:fr10jn09-11

ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 180

EPA-HQ-OPP-2007-0395; FRL-8412-1

Residues of Silver in Foods from Food Contact Surface Sanitizing

Solutions; Exemption from the Requirement of a Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation amends the exemption from the requirement of a tolerance for residues of silver (excludes silver salts) in or on all foods when applied or used in public eating places, dairy processing equipment, and food-processing equipment. ETO H2O, Inc., submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act requesting to establish concentration limits for silver in end-use solutions eligible for tolerance exemption. The regulation being established will exempt all foods from the requirement of a tolerance for residues of silver resulting from contact with surfaces treated with solutions in which the end-use concentration of silver is not to exceed 50 parts per million (ppm).

DATES: This regulation is effective June 10, 2009. Objections and requests for hearings must be received on or before August 10, 2009 and must be filed in accordance with the itructions provided in 40 CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket identification (ID) number EPA-HQ-OPP-2007-0395. To access the electronic docket, go to http://www.regulations.gov, select ``Advanced

Search,'' then ``Docket Search.'' Insert the docket ID number where indicated and select the ``Submit'' button. Follow the instructions on the regulations.gov web site to view the docket index or access available documents. All documents in the docket are listed in the docket index available in regulations.gov. Although listed in the index, some information is not publicly available, e.g., Confidential

Business Information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either in the electronic docket at http:// www.regulations.gov, or, if only available in hard copy, at the Office of Pesticide Programs (OPP) Regulatory Public Docket in Rm. S-4400, One

Potomac Yard (South Building), 2777 S. Crystal Drive Arlington, VA. The hours of operation of this Docket Facility are from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The Docket telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Marshall Swindell, Antimicrobials

Division (7510P), Office of Pesticide Programs, Environmental

Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460- 0001; telephone number: (703) 308-6341; e-mail address: swindell.marshal@epa.gov.

SUPPLEMENTARY INFORMATION:

1. General Information

   1. Does this Action Apply to Me?

      You may be potentially affected by this action if you are a dairy cattle milk producer, food manufacturer, or beverage manufacturer.

      Potentially affected entities may include, but are not limited to:

      Food Manufacturing (NAICS code 311).

      Beverage Manufacturing (NAICS code 3121).

      Dairy Cattle Milk Production (NAICS code 11212).

      This listing is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be affected by this action. Other types of entities not listed in this unit could also be affected. The North American Industrial Classification System (NAICS) codes have been provided to assist you and others in determining whether this action might apply to certain entities. To determine whether you or your business may be affected by this action, you should carefully examine the applicability provisions in 40 CFR 180.940 (a)

      Tolerance exemptions for active and inert ingredients for use in antimicrobial formulations (Food-contact surface sanitizing solutions).

      If you have any questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER

      INFORMATION CONTACT.

   2. How Can I Access Electronic Copies of this Document?

      In addition to accessing an electronic copy of this Federal

      Register document through the electronic docket at http://

      Page 27448

      www.regulations.gov, you may access this Federal Register document electronically through the EPA Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr. You may also access a frequently updated electronic version of 40 CFR part 180 through the

      Government Printing Office's pilot e-CFR site at http:// www.gpoaccess.gov/ecfr.

   3. Can I File an Objection or Hearing Request?

      Under section 408(g) of the FFDCA, as amended by the FQPA, any person may file an objection to any aspect of this regulation and may also request a hearing on those objections. The EPA procedural regulations which govern the submission of objections and requests for hearings appear in 40 CFR part 178. You must file your objection or request a hearing on this regulation in accordance with the instructions provided in 40 CFR part 178. To ensure proper receipt by

      EPA, you must identify docket ID number EPA-HQ-OPP-2007-0395 in the subject line on the first page of your submission. All requests must be in writing, and must be mailed or delivered to the Hearing Clerk on or before August 10, 2009.

      In addition to filing an objection or hearing request with the

      Hearing Clerk as described in 40 CFR part 178, please submit a copy of the filing that does not contain any CBI for inclusion in the public docket that is described in ADDRESSES. Information not marked confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA without prior notice. Submit your copies, identified by docket ID number EPA-HQ-OPP-2007-0395, by one of the following methods:

      Federal eRulemaking Portal: http://www.regulations.gov.

      Follow the on-line instructions for submitting comments.

      Mail: Office of Pesticide Programs (OPP) Regulatory Public

      Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania

      Ave., NW.,Washington, DC 20460-0001.

      Delivery: OPP Regulatory Public Docket (7502P),

      Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South

      Building), 2777 S. Crystal Drive, Arlington, VA. Deliveries are only accepted during the Docket's normal hours of operation (8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays). Special arrangements should be made for deliveries of boxed information. The docket telephone number is (703) 305-5805.

2. Background and Statutory Findings

   In the Federal Register of July 11, 2007 (72 FR 37779) (FRL-8136- 1), EPA issued a notice pursuant to section 408(d)(3) of the FFDCA, 21

   U.S.C. 346a(d)(3), announcing the filing of an pesticide tolerance petition (PP 7F7178) by ETO H20, Inc, 1725 Gillespie Way, El Cajon, CA 92020. The petition requested that 40 CFR 180.940(a) be amended by establishing concentration limits for Silver in end-use solutions eligible for the tolerance exemption in all foods from treatment of food contact surfaces in public eating establishments, dairy processing equipment, and food processing equipment and utensils not to exceed silver at 50 ppm. The notice referenced a summary of the petition prepared by ETO H20, Inc., 90 Boroline Rd Allendale, NJ 07401, the registrant, which is available to the public in the docket at www.regulations.gov, Docket ID Number EPA-HQ-OPP-2007-0395. There were no comments received in response to the notice of filing.

   In drafting the regulatory language for this exemption, EPA has adopted more restrictive language than suggested in the petition to ensure that the scope of the exemption does not exceed the form of silver evaluated in the risk assessment supporting this action. As revised, the tolerance expression would now read:

   Silver ions resulting from the use of electrolytically-generated silver ions stabilized in citric acid as silver dihydrogen citrate

   (does not include metallic silver).

   This revised tolerance expression excludes any other silver-containing compounds whether they are other silver salts, complexes with inorganic polymers such as zeolites, or metallic silver in any form or dimension including nanoscale.

   EPA understands that this petition was not intended to extend to silver salts accordingly EPA has modified the regulatory language to make this clear.

   Section 408(c)(2)(A)(i) of the FFDCA allows EPA to establish an exemption from the requirement for a tolerance (the legal limit for a pesticide chemical residue in or on a food) only if EPA determines that the tolerance is ``safe.'' Section 408(c)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical residue, including all anticipated dietary exposures and all other exposures for which there is reliable information.'' This includes exposure through drinking water and in residential settings, but does not include occupational exposure. Pursuant to section 408(c)(2)(B), in establishing or maintaining in effect an exemption from the requirement of a tolerance, EPA must take into account the factors set forth in section 408(b)(2)(C), which requires EPA to give special consideration to exposure of infants and children to the pesticide chemical residue in establishing a tolerance and to ``ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue....''

   EPA performs a number of analyses to determine the risks from aggregate exposure to pesticide residues. First, EPA determines the toxicity of pesticides. Second, EPA examines exposure to the pesticide through food, drinking water, and through other exposures that occur as a result of pesticide use in residential settings.

3. Toxicological Profile

   1. Toxic Effects

      Consistent with section 408(b)(2)(D) of FFDCA, EPA has reviewed the available scientific data and other relevant information in support of this action and considered its validity, completeness and reliability and the relationship of this information to human risk. EPA has also considered available information concerning the variability of the sensitivities of major identifiable subgroups of consumers, including infants and children. The nature of the toxic effects caused by silver are discussed in this unit.

      Silver ions and preparations containing silver in an ionic state have been used for over a century for medicinal and bactericidal purposes. Because of its bactericidal properties, silver has been used as a topical treatment for burns, as a treatment for venereal diseases, as an ingredient in cosmetic formulations and in the sanitation of swimming pools and hot tubs/spas. Silver has also been used in dentistry (as amalgams and as an ingredient in mouth washes), in acupuncture, jewelry making, and photography. Silver can be found in electroplating as well as in paints and in water purification systems.

      The toxicity of silver is well understood based on epidemiological data from humans, toxicology data in animals, and documented information on the metabolism of silver in mammalian species. Unlike for other pesticides, EPA does not have a conventional check-list of guideline laboratory animal studies to assess human risk from exposure to silver. Based on the extensive past uses of

      Page 27449

      silver and EPA's knowledge and experience about those uses of the compound, however, it is apparent that humans and laboratory animals do not handle elevated doses of silver in the same manner. For this reason, additional conventional laboratory animal toxicity studies would not provide a better understanding of the effects of silver in humans. Further, the Agency has determined that silver and several of its salts (chloride, sulfate nitrate and acetate) can be reviewed together because these silver salts react similarly in aqueous media and the major active ion is the silver ion.

      A human biomonitoring study conducted in 1935, as reported in the

      Journal of the American Medical Association by L.E. Gaul and H.E.

      Staud, has served as the basis for establishing regulatory limits for silver in drinking water and in the diet. The results from this study were further supported by the results from an inhalation study conducted by Pillsbury and Hill in 1939, which established inhalation limits for silver in humans. In both studies, the effect of concern was argyria, a bluish discoloration of the skin. Argyria, while a permanent condition, is a cosmetic condition. The function of the skin as an organ is not compromised and the resulting discoloration is not associated with systemic toxicity. In the 1935 study by Gaul and Staud, silver was administered for medicinal purposes to 70 patients for periods from 2 to 9 years. Of the 70 patients receiving medicinal silver, 1/70 developed argyria after receiving an intravenous dose of 1 gram. This intravenous dose was converted to an oral dose of 0.014 milligram/kilogram/day (mg/kg/day) and was considered a lowest observed effect level. Other patients did not develop argyria until doses five times higher were administered. This study and an inhalation biomonitoring study by Pillsbury, et al, clearly determined the endpoint of concern for humans. Interestingly, the skin form of argyria has not been reported in laboratory animals when doses that are approximately 4 orders of magnitude higher (100 mg/kg) are administered.

      Further support for not requiring additional laboratory animal studies for silver is provided from the results of the developmental toxicity study in rats, conducted by the National Toxicology Program

      (NTP). In a developmental study conducted in 2002, silver acetate was administered by gavage on days 6 - 19 of gestation. No developmental effects were reported at doses up to 100 mg/kg; maternal animals were observed to have piloerection and rooting behavior at 30 mg/kg. The observed effects in maternal animals would not be expected to occur in humans and are frequently observed in animal studies. These observations, when made in the absence of other clinical findings are not considered adverse when establishing a ``no adverse effect level.''

      More importantly, the results from this study did not demonstrate an increased susceptibility of offspring, nor did it demonstrate systemic toxicity. This study corroborates the use of the information provided by the human biomonitoring study in determining dietary limits for silver and further supports our decision to not rely on animal data when assessing the health effects of silver in humans.

      In addition to the information gleaned from the biomonitoring studies and the developmental toxicity study, the reviews of the literature by other EPA offices and national and inter-national organizations provide supplemental support that argyria is the primary effect in humans (e.g. EPA's Integrated Risk Management System, Agency for Toxic Substances and Disease Registry, the World Health

      Organization). Also the acute oral toxicity studies that have been provided to support the registration of silver as an antimicrobial agent establish LD50sbetween 2,000 and 5,000 mg/kg. These values are above the limit dose for acute toxicity. For other silver salts, such as silver cyanide, the LD50values may be significantly lower based on the molecules to which the silver ions are attached. For the antimicrobial silver covered by this exemption, the

      LD50ranges are very high because the silver ions have very low acute toxicity.

      Finally, the pharmacokinetics of silver is understood and may explain the low systemic toxicity potential of the compound.

      Pharmacokinetics describes what the body does to a chemical when it is introduced into the body including how it is metabolized, distributed, and eliminated. When silver is introduced into the body by the oral or dietary route, it is absorbed by the digestive system and then enters the liver before it reaches the rest of the body (referred to as first- pass metabolism). This first pass through the liver greatly reduces the bioavailability of silver in that about 90% of the orally administered dose is eliminated in the feces. The remaining 10% that is not eliminated in the feces, reacts with proteins by binding to a specific chemical group contained in the structure of the protein. By forming silver-protein complexes through this binding action, the remaining silver is removed from circulation. This remaining fraction accounts for the background levels of silver that are found within the body. At excessive doses, the pathways of elimination become saturated and deposition of these complexes in the tissues is increased. The formation of these complexes and deposition in the skin, mucous membranes, and conjunctiva is the primary mechanism which results in the development of argyria. Based on information from biomonitoring studies, the lowest observed effect level for the formation of argyria was 1 gram (total dose), which was converted to an oral dose of 0.014 mg/kg/day.

   2. Regulatory Levels

      Safe exposure levels for silver have been established by several regulatory Agencies including the Food and Drug Administration,

      Occupational Safety and Health Administration and other offices within

      EPA based on the common endpoint argyria and using the same human studies. Argyria is a blue-gray discoloration of the skin and is not considered as being of toxicological concern. Argyria is cosmetically disfiguring and permanent in nature; however, the occurrence of this condition does not adversely affect organ function or threaten human health. EPA believes that by regulating for argyria, it is protecting the public from this permanent cosmetic effect as well as any potential toxic manifestations of silver that may occur at much higher doses.

      There is no animal condition that would mimic the dermatologic form of argyria found in humans following exposure to silver by various routes.

      This may be due in part to the protection imparted by the presence of the fur or by the fact that laboratory animal species are not routinely exposed to direct sunlight. Argyrosis, a form of argyria which involves silver deposition in organs, has been documented. In laboratory species, the effects of silver toxicity have been reported to involve pathology to the liver (necrosis) and kidney (thickening of the basement membranes of the glomeruli), and, at elevated levels, death.

      The effect on which silver is regulated (argyria) occurs only after chronic exposure. Both the Secondary Maximum Contamination Level (SMCL) reported by the EPA's Office of Water and the oral reference dose (RfD) reported under the EPA's Integrated Risk Information System (IRIS) were determined based on the previously-mentioned human biomonitoring by

      Gaul and Staud. For the SMCL, additional mathematical derivations were applied to the oral equivalent dose

      Page 27450

      to the study Lowest Observed Adverse Effect Level (LOAEL) of 0.014 mg/ kg/day to obtain a 0.1 milligram/Liter (mg/L) dose level. The factors applied for changing volume to mass account for the slight difference in the values reported for the SMCL (0.003 mg/kg/day) and for the RfD

      (0.005 mg/kg/day).

      In deriving the chronic dietary regulatory level (RfD) and the

      SMCL, a safety factor of 3X was applied based on the following rationale as reported by the Office of Water and IRIS. First, the critical effect was cosmetic and not of toxicological significance.

      Second, the derivation of the LOAEL included the most sensitive individual since other patients did not present with argyria unless dose levels five times higher were administered. Finally, in the human biomonitoring study, silver was administered to these individuals over a period of time that is in excess of chronic exposure and that approaches a level that would be considered a life time exposure duration. Therefore, the dose that was administered was determined as being one that would mimic lifetime exposure.

      For the oral exposure route, the Agency is relying on the drinking water Secondary Maximum Contaminant Level (SMCL) of 0.1 mg/L (0.003 mg/ kg/day) based on skin discoloration and graying of the whites of eyes

      (argyria). The Agency applied an additional 3X uncertainty factor to further address the lack of a NOAEL in the study on which this assessment and all regulatory advisories are set. This additional 3X factor was not imposed due to the lack or need for additional standard animal toxicity testing. Thus, a composite database factor of 10X is being applied to account for a lack of NOAEL in the Gaul and Staud

      (1935) study. This composite factor of 10 should be sufficient for providing protection from the non-toxic effects which may result from chronic oral exposure to silver.

      Chronic Dietary Reference Dose (RFD) = 0.003 mg/kg/day / 3 = 0.001 mg/kg/day

      Alternatively, a roughly equivalent chronic RfD can be derived by dividing the oral equivalent dose from the Gaul and Staud study (0.014 mg/kg/day) by a factor of 10X.

      Following dermal exposure, silver ions tend to bind to the skin and do not penetrate the skin to cause systemic effects. Rather, skin discoloration is the only effect induced by silver exposure through the dermal route. Although this discoloration appears to be the same effect that results from oral and inhalation exposure, the mechanism by which discoloration occurs following dermal exposure is not the same as the mechanism leading to argyria following other routes of exposure.

      Systemic uptake and distribution of silver following dermal exposure does not occur, and the discoloration is the result of a localized reaction. Again, the effect is not adverse and there is no reason to believe that there would be an increase in susceptibility based on age to the nontoxic discoloration. Susceptibility to this cosmetic event is a function of dose and not age.

4. Aggregate Exposures

   To establish a tolerance, it must be shown ``that there is reasonable certainty that no harm will result from aggregate exposure to pesticide chemical residue, including all anticipated dietary exposures and other exposures for which there are reliable information.'' Aggregate exposure is the total exposure to a single chemical (or its residues) that may occur from dietary (i.e., food and drinking water), residential, and other non-occupational sources, and from all known or plausible exposure routes (oral, dermal, and inhalation).

   Silver is commonly used for a variety of non-pesticidal industrial uses, which include but are not limited to photography, cosmetics, sunscreens, manufacture of inks and dyes, mirror production, and in jewelry. These sources result in primary exposures being via the dermal route. As previously mentioned, the consequence of silver exposures via the dermal route is dermal argyria, which does not contribute to the systemic argyria induced by oral and inhalation routes of exposures.

   Silver has also been used in dentistry (as amalgams) and as an ingredient in mouth washes. However, there is no documented evidence of argyria developing from dental or mouth wash uses of silver despite its widespread and frequent use in dentistry for over a century; consequently, EPA concludes that the level of exposure from the dental and mouthwash uses is negligible. Therefore, EPA did not aggregate the exposures resulting from these various uses with pesticidal exposure sources.

   1. Dietary Exposure

      Under the current proposal (PP 7F7178), silver will be used as a sanitizer for food contact surfaces, resulting in dietary, drinking water, and residential exposures. The use sites include but are not limited to: Food service facilities, cafeterias, households, kitchens, food preparation areas, food processing equipment and treated surfaces, such as countertops, equipment, and appliances. The sanitizing solution is applied to these various surfaces by spraying (trigger, spraying, coarse pump), wiping with a cloth or sponge, mopping, or by full immersion. As a result of these uses, residues are expected to transfer to the food that comes into contact with these treated surfaces and subsequently to be ingested by humans. 1. Food. The Agency assessed chronic dietary exposure from the use of silver as a food contact sanitizer. The dietary assessment was only completed for chronic routes because the regulatory effect that has been identified is based on argyria, one that occurs only after chronic exposure. For dietary exposures from this product being used on countertops, the Incidental Dietary Residential Exposure Assessment

      Model, IDREAMTMincorporates consumption data from USDA's

      Continuing Surveys of Food Intakes by Individuals (CSFII), 1994-1996 and 1998. The 1994-1996, and 1998 data are based on the reported consumption of more than 20,000 individuals over two non-consecutive survey days. The maximum rate for silver is 50 ppm active ingredient.

      The use on utensils, dishes and glass was assessed. Based on conservative calculations, risk concerns were identified. At this time, a label restriction will be required that prohibits the use on utensils, dishes and glassware until a residue transfer study has been conducted and accepted by the Agency.

      Agricultural Premises-Dairy Facilities. Dietary exposures from these general premise uses are expected to be much lower than the dietary exposure resulting from the surface disinfectant and sanitizing uses considered for this tolerance exemption: therefore, the agricultural uses were not assessed separately. However, the sanitization of food processing equipment permits product contact with the interior of equipment. The milk-truck model (described in the FDA document, ``Sanitizing Solutions: Chemistry Guidelines for Food

      Additive Petitions'', pages 9-10)(FDA 2003) for these types of uses was executed in order to estimate residues that could transfer from treated surfaces to food. From this guidance, it was conservatively assumed that a child will consume 320 grams of milk per day (90th percentile value) and an adult will consume 125 grams milk per day (mean value).

      Because EPA has utilized this maximized value for children along with a child's body weight in this assessment, EPA has confidence that the calculations are conservative and representative of any potential risks to any population.

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      The Agency assumes that the sanitized tank truck which transports the milk is a conservative estimate of residue that is available in food processing facilities.

      Milk undergoes no additional dilution prior to reaching the consumer and it is also assumed that 100% of the residues available post sanitation is transferred to the food.

      Additionally, the dietary contribution as a result of food processing equipment sanitization is so extremely small that it is considered negligible and not included in the combined or aggregate assessments. 2. Drinking water exposure. There are no outdoor or potable human drinking water system uses for the use of silver proposed in pesticide petition (PP) 7F7178. In addition, the uses identified as indoor hard surface applications will result in minimal, if any, runoff of silver into the surface water. The use of silver as a food contact surface sanitizer will result in minimal, if any, runoff of silver into the surface water. This use will result in an insignificant contribution to drinking water exposures. In addition to sanitization, silver is registered as an active ingredient in water filters. The bacteriostatic water filters are impregnated with silver and may result in residues in the drinking water supply. However, the levels of available residues resulting from impregnated water filters are much less when in comparison to the amount of residues that will be available for intake when silver-containing liquid concentrates are used. As a result, any drinking water exposures from the new use of silver are assumed to be negligible. Additionally, any drinking water risks from impregnated filters are assumed to be represented by the dietary risks resulting from hard surface sanitization. The Agency believes that an assessment of any potential risks resulting from silver in drinking water is not warranted at this time.

      Therefore, based on the uses of silver outlined in the pesticide petition, the Agency believes that risks resulting from silver in drinking water will be negligible and that an assessment is not warranted at this time.

      Table 1 provides a comprehensive summary of all of the use patterns potentially resulting in dietary exposure that were considered for this tolerance exemption.

      Table 1.--Potential Use Scenarios

      Use Site Category

      Example Use Sites

      Scenarios

      Use Site Category I:

      Dairy farms, hog

      Application to

      Agricultural Premises and

      farms, equine

      hard surface

      Equipment

      farms

      (feeding dishes, bottling equipment, floors, etc) through coarse spraying (low pressure spray), trigger pump spray, wipe/ sponge, mop, and immersion

      Use Site Categories II, III, and Food processing

      Application to

      V: Food Handling, Commercial/

      plants;

      hard surfaces

      Institutional/Industrial,

      Hospitals; Public through coarse

      Medical

      places (e.g.,

      spraying (low restaurants,

      pressure spray), hotel/motel

      trigger pump rooms); Medical/ spray, wipe/

      Dental offices;

      sponge, mop, and

      Nursing home;

      immersion.

      Schools, Cruise

      Some examples of ships, Dining

      surfaces include:

      Halls.

      sinks, cutting boards, counter tops, kitchen appliances, breast pumps and parts, baby bottles, ice chests, and various others that are summarized on the proposed label.

      Use Site Category IV:

      Homes, kitchens

      Application to

      Residential and Public Access

      hard surfaces

      Premises

      through coarse spraying (low pressure spray), trigger pump spray, wipe/ sponge, mop, and immersion.

      Examples of the hard surfaces include those identified for

      Use Site

      Categories II,

      III, and V.

   2. Other Non-Occupational Exposure

      The residential exposure assessment considers all potential non- occupational pesticide exposure, other than exposure due to residues in food or in drinking water. Exposures may occur during and after application on hard surfaces (e.g., floors). Each route of exposure

      (incidental oral, dermal, inhalation) is considered where appropriate.

      The risks to handlers are quantitatively assessed based on the nature of the chemical. As previously stated, there are no adverse toxicological consequences (systemic or irritation) resulting from contact with silver other than skin discoloration. Residential exposures are short-term (