Butacarb

Biological Exposure Indices (BEI) [ACGIH] - Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

The protective clothing should be kept in separate places where it cannot be contaminated with toxic chemicals. It should be forbidden to keep this clothing in living quarters. Protective clothing must be washed at least once a week and each time it is contaminated with pesticides. Before washing the clothing should be soaked for several hours in a calcium carbonate solution. /Pesticides/

Smoking, eating, and drinking before washing should be absolutely prohibited when any pesticide ... is being handled or used. /Pesticides/

If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.

...Feature of insecticidal action of... carbamates is pronounced synergism shown by addition of methylenedioxy compound such as piperonyl butoxide, sesoxane, and propyl isome... these prevent in vivo detoxication of carbamates by inhibiting "mixed function oxidase" detoxification system. /Carbamates/

Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Chronically high (>10 years) exposure leads to neuropsychological consequences including disturbances in perception and visuo-motor processing (A15321).

LC50 Rasbora heteromorpha (Harlequinfish, red rasbora) 610 ug/L/24 hr; renewal /formulated product/

LC50 Rasbora heteromorpha (Harlequinfish, red rasbora) 580 ug/L/48 hr; renewal /formulated product/

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 980(SRC), determined from a water solubility of 15 mg/L(2) and a regression-derived equation(3), indicates that butacarb is expected to have low mobility in soil(SRC). Volatilization of butacarb from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.6X10-8 atm-cu m/mole(SRC), derived from its vapor pressure, 1.98X10-6 mm Hg(4), and water solubility(2). Butacarb is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Biodegradation data were not available(SRC, 2005).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 980(SRC), determined from a water solubility of 15 mg/L(2) and a regression-derived equation(3), indicates that butacarb is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 4.57X10-8 atm-cu m/mole(SRC), derived from its vapor pressure, 1.98X10-6 mm Hg(4), and water solubility(2). According to a classification scheme(5), an estimated BCF of 130(SRC), from its water solubility(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Biodegradation data were not available(SRC, 2005).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), butacarb, which has a vapor pressure of 1.98X10-6 mm Hg at 25 °C(2) is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase butacarb is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 26 hours(SRC), calculated from its rate constant of 14X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase butacarb may be removed from the air by wet and dry deposition(SRC). Butacarb does not contain chromophores that absorb at wavelengths >290 nm and would not be expected to be susceptible to direct photolysis by sunlight(SRC).

Butacarb is a cholinesterase or acetylcholinesterase (AChE) inhibitor. Carbamates form unstable complexes with chlolinesterases by carbamoylation of the active sites of the enzymes. This inhibition is reversible. A cholinesterase inhibitor suppresses the action of acetylcholine esterase. Because of its essential function, chemicals that interfere with the action of acetylcholine esterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses. Headache, salivation, nausea, vomiting, abdominal pain and diarrhea are often prominent at higher levels of exposure. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop.

As with organophosphates, the signs and symptoms are based on excessive cholinergic stimulation. Unlike organophosphate poisoning, carbamate poisonings tend to be of shorter duration because the inhibition of nervous tissue acetylcholinesterase is reversible, and carbamates are more rapidly metabolized. Muscle weakness, dizziness, sweating and slight body discomfort are commonly reported early symptoms. Headache, salivation, nausea, vomiting, abdominal pain and diarrhea are often prominent at higher levels of exposure. Contraction of the pupils with blurred vision, incoordination, muscle twitching and slurred speech have been reported. (L795)

The Koc of butacarb is estimated as 980(SRC), using a water solubility of 15 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that butacarb is expected to have low mobility in soil(SRC).

/SIGNS AND SYMPTOMS/ Symptomatology: Nausea, vomiting, abdominal cramps, diarrhea & excessive salivation... sweating. Lassitude & weakness. Rhinorrhea and sensation of tightness in chest may occur with inhalation exposure. Blurring or dimness of vision. Miosis ... tearing, ciliary muscle spasm, loss of accommodation and ocular pain. None of these ... signs ... is dependable for diagnosis. Mydriasis may be seen ... Loss of muscle coordination, slurring of speech, fasciculation & twitching of muscles. Difficulty in breathing, excessive secretions of saliva and of respiratory tract mucus, oronasal frothing, cyanosis, pulmonary rales & rhonchi, and hypertension. ... Jerky movements, incontinence, convulsions and coma. Death ... due to respiratory arrest of central origin, paralysis of respiratory muscles, intense bronchoconstriction or all three.

/SIGNS AND SYMPTOMS/ The clinical picture of carbamates intoxication results from accumulation of ACh at nerve endings. ...The signs and symptoms can be categorized into the following 3 groups: (a) Muscarinic manifestations - increased bronchial secretion, excessive sweating, salivation, and lachrymation; pinpoint pupils, bronchoconstriction, abdominal cramps (vomiting and diarrhea); and bradycardia. (b) Nicotinic manifestations - fasciculation of fine muscles (in severe cases, diaphragm and respiratory muscles also involved); and tachycardia. (c) Central nervous system manifestations- headache, dizziness, anxiety, mental confusion, convulsions, and coma; and depression of respiratory center. All these signs and symptoms can occur in different combinations and can vary in onset and sequence, depending on the chemical, dose, and route of exposure. The duration of symptoms is usually shorter than that observed in organophosphorus poisoning. Mild poisoning might include muscarinic and nicotinic signs only. Severe cases always show central nervous system involvement; the clinical picture is dominated by the respiratory failure sometimes leading to pulmonary edema due to the combination of the above mentioned symptoms. /Carbamate pesticides/

Used as insecticide and to control blowfly larvae in sheep; Not marketed in the US; [HSDB]

Not currently registered with the EPA for use in the US; [HSDB]

Farming (Pesticides) [Category: Industry]

For butacarb (USEPA/OPP Pesticide Code: 291300) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

Insecticide

... Mixture with gamma-HCH against animal ectoparasites.

Very effective against larval stages of sheep blow fly. In sheep dips at 50 g ai/100 l gives protection from blow fly strike 10 to 12 weeks.

Compatible with most other pesticides

Not marketed in /United States/

FRASER, HARRISON, BRITISH PATENT 987,254 (1965 TO BOOTS PURE DRUG); KAEDING ET AL, J AGR FOOD CHEM 13, 215 (1965).

Discontinued by The Boots Co Ltd