Rodenticides

Sodium fluoroacetate, which is not volatile and not irritating to the skin, is used as a rodenticide. It is made from CH2ClC02Et and KF, which react to give ethyl fluoroacetate, which is then hydrolysed with NaOH in methyl alcohol. 

Fluoroacetic acid [144-49-OJ, FCH2COOH, is noted for its high, toxicity to animals, including humans. It is sold in the form of its sodium salt as a rodenticide and general mammalian pest control agent. The acid has mp, 33°C bp, 165°C heat of combustion, —715.8 kJ/mol( —171.08 kcal/mol) (1) enthalpy of vaporization, 83.89 kJ /mol (20.05 kcal/mol) (2). Some thermodynamic and transport properties of its aqueous solutions have been pubHshed (3), as has the molecular stmcture of the acid as deterrnined by microwave spectroscopy (4). Although first prepared in 1896 (5), its unusual toxicity was not pubhshed until 50 years later (6). The acid is the toxic constituent of a South African plant Dichapetalum i mosum better known as gifirlaar (7). At least 24 other poisonous plant species are known to contain it (8). 

Toxicity. Sodium fluoroacetate is one of the most effective all-purpose rodenticides known (18). It is highly toxic to all species of rats tested and can be used either in water solution or in bait preparations. Its absence of objectionable taste and odor and its delayed effects lead to its excellent acceptance by rodents. It is nonvolatile, chemically stable, and not toxic or irritating to the unbroken skin of workers. Rats do not appear to develop any significant tolerance to this compound from nonlethal doses. However, it is extremely dangerous to humans, to common household pets, and to farm animals, and should only be used by experienced personnel. The rodent carcasses should be collected and destroyed since they remain poisonous for a long period of time to any animal that eats them. 

Fluoroacetamide. Fluoroacetamide [640-19-7], FCH2CONH2, is a white water-soluble soHd having mp 108°C (14). It has been used as a rodenticide and has been reported to have a better acceptability to rats than sodium fluoroacetate (29). However, like the latter compound, its misuse has caused deaths to farm animals and pets (20). 

The tria2ine family of herbicides appeared in and after 1955, and the bipyridiniums in 1960. In 1967, two new chemical herbicides (1) were registered under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The number of new registrations swelled to 11 in 1975 and subsequendy dropped to three in 1990 and two in 1991. 

Several antimicrobials have been banned or severely restricted by the EPA based on documented or suspected toxicity or environmental problems. Others have been discontinued in the face of testing costs required by the EPA reregistration program mandated by the Pederal Insecticide, Pungicide, and Rodenticide Act (PIPRA) of 1988 (10). Some of the significant products that have become obsolete are 2,4,5-trichlorophenol/P3 -5 3 -47, sodium... 

Naphthaleneamine is a dye intermediate and is used as the starting material in the manufacture of the rodenticide, Antii (8), l-naphthalenethiourea/5 %< < -4/, which is prepared by heating a mixture of 1-naphthylamine hydrochloride, NH SCN, and a large amount water for 14—16 h while keeping its volume constant by a dding an additional amount of water, to give a 97% yield. Its LD q is 600 mg in squirrels (46). 

Pesticides are more closely regulated than other chemicals because pesticides are intentiaHy appHed in the environment, often repeatedly at relatively high rates. In the United States, pesticides are regulated under the federal Insecticide, fungicide and Rodenticide Act (EIERA), and residues from uses of pesticides in food or feed crops are regulated under Sections 408 and 409 of the federal food, Dmg and Cosmetics Act (EEDCA). 

The two main federal agencies involved in the protection of human health and the environment are the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA). EPA s principal concern is the protection of the environment, in most cases, the area outside of an industrial faciUty. There are 10 regional offices that carry out the regulatory functions of the agency (Table 1). Primary laws covered by EPA are the Clean Air Act Amendments (CAAA), the Clean Water Act (CWA), Resource Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and LiabiUty Act (CERCLA), Toxic Substances Control Act (TSCA), and Eederal Insecticide, Eungicide, and Rodenticide Act (FIFRA). 

Strychnine (1), an alkaloid, was introduced into European medical practice in the early sixteenth century after being used as a rat poison (see Alkaloids). As of 1996, it was stiU used as a rodenticide. The total synthesis of this complex molecule is known (3,4). 

Uses. Tballium compounds have limited use in industrial appHcations. The use of thaHous sulfate in rodenticides and insecticides has been replaced by other compounds less harmful to animals (see Insect control technology Pesticides). Tb allium sulfide has been used in photoelectric cells (see Photovoltaic cells). A thallium bromide—thallium iodide mixture is used to transmit infrared radiation for signal systems. ThaHous oxide is used in the manufacture of glass (qv) that has a high coefficient of refraction. Tb allium formate—malonate aqueous solutions (Cletici s solution) have been used in mineral separations. Many thallium compounds have been used as reagents in organic synthesis in researchlaboratoti.es. 

Herbicide bromacd [31440-9] C2H 2BiN202 Rodenticide bromadiolone [28772-56-7] C30H23B1O4... 

More than 80% of all the sodium chlorite produced is used for the generation of chlorine dioxide. Sodium chlorite or the chlorine dioxide generated from it or from sodium chlorate must be registered with the USEPA for each specific appHcation use as a biocide for microbial growth control or disinfection. These regulations are covered under the Eederal Insecticide, Eungicide, and Rodenticide Act (EIERA). 

Warfarin [81-81-2] (6) is prepared by the Michael condensation of benzyHdene acetone with 4-hydroxycoumarin (86). It is used as a rodenticide (see Poisons, commercial) and in anticoagulant therapy. 

The use of black cyanide as a fumigant and rodenticide makes use of the atmospheric humidity action that Hberates hydrogen cyanide gas. It can only be used effectively ia confined spaces where hydrogen cyanide builds up to lethal concentrations for the particular appHcation. Black cyanide is also used ia limited quantities ia the production of pmssiates or ferrocyanides (see Iron compounds). 

The United States has the most laws regarding environmental safety and health. The National Environmental PoHcy Act (NEPA) of 1969 has resulted in the following acts Eederal Insecticides, Eungicide and Rodenticide (EIERA), Resource Conservation and Recovery (RCRA), Superfund (CERCLA), Superfund Amendments and Reauthori2ation Act (SARA) Plus Tide III, Toxic Substance Control Act (TSCA), Clean Water (CWA), Water Quahty, Safe Drinking Water (SDWA), and Waste Minimi2ation and Control. 

Resource Conservation and Recovery Act Federal Insecticide, Fungicide, and Rodenticide Act Toxic Substances Control Act Nuclear Regulatory Commission Title 10... 

Another section of the EPA, the Office of Prevention, Pesticides, and Toxic Substances (OPPT), has recently updated and harmonized its testing guidelines for evaluating the developmental and reproductive effects of pesticides and industrial chemicals to include an assessment of endocrine disrupting properties. These guidelines will be used in future testing of pesticides under both the Toxic Substances Control Act (TSCA) and the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). 

The variation in toxicity of common organophosphate insecticides is exemplified in Table 5.37. The range of chlorinated hydrocarbon insecticides (Table 5.38) have, with the exception of Endrin and Isodrin, somewhat lower oral and dermal toxicities. The toxicities of a range of oilier insecticides, fungicides, herbicides and rodenticides are summarized in Table 5.39. 

Table 5.39 Insecticides, rodenticides, fungicides and herbicides (see also Table 5.12) ...

Zineb Rodenticides Sodium Fluoroacetate Strychnine Thallium Sulphate Warfarin 5200 0.05 SK 0.15 0.1 as Tl, SK 0.1... 

Pesticides (includes acaricides, avicides, bactericides, insecticides, molluskicides, nematocides, piscicides, rodenticides) Pharmaceuticals... 

Preventing Access to Effluent Storage and Similar Areas on Earms Guidance on Storing Pesticides for Earmers and other Professional Users Safe Use of Rodenticides on Earms and Holdings Earmer s Lung... 

Pesticides include the broad categories of insecticides, fungicides, rodenticides, and herbicides. Insecticides in common use fall into three categories. The chloroinsec-ticides have chlorine in their structure. They are less soluble than the other insecticide forms and much less biodegradable (i.e., more persistent). While they are less acutely toxic, several have been identified as potential carcinogens. Carbamatea are a relatively new form of pesticide. They are less persistent and less... 

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