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At least 19 recordsLinked to original sources
PubMed1975

Analysis of fumigants and fumigant residues.

The terms fumigant and fumigant residue are defined. Interrelationships between physically and chemically bound residues, storage environments, nature of the substrate and other influencing factors are outlined. Analytical methods include polarography by DME and RPE, titrimetry, spectrophotometry, and GC with microthermal conductivity, hydrogen flame ionization, electron capture, microcoulometric, thermionic, and flame photometric detector systems, with backup by enzymatic, radiometric, NAA and X-ray flourescence methods. Various aspects are illustrated with different fumigants used commercially. Supplementary methods to extend the power and usefulness of analytical methods in fumigant research are indicated.

Bromides↗
PubMed1990

Occupational and environmental hygiene assessment of fumigations with methyl bromide.

Use of methyl bromide for pest control fumigation may result in adverse exposure to three populations: the actual fumigators; other workers not actually involved in the fumigation; and the general public in the vicinity. The risk of exposure of these three target populations in Switzerland was investigated. The methodology was a combination of occupational hygiene surveys, including a preliminary hazard analysis, with a comprehensive assessment of the safety and health systems in use based on the 'Management Oversight and Risk Tree' (MORT) method [Knox and Eicher, MORT User's Manual, Revision 2. DOE 76-45/4 (1983)]. The target populations most concerned depend on the type of fumigation. Fumigators risk severe accidental exposure although they usually wear personal protection devices. In soil and chamber fumigation, workers not involved in the fumigation may undergo high exposure (75-100 pm for 1 h), far greater than the usual time-weighted average and short-term occupational exposure limits (5-20 ppm range). Occupants of premises adjoining the fumigated buildings may also be exposed to significant concentrations (25-50 ppm for 0.1-2 h). Problems originate mainly from a lack of management controls, failure to apply an appropriate code of practice and the use of personnel who are not properly qualified and trained.

Air Pollutants↗
PubMed1991

Fumigants and related chemicals in foods: review of residue findings, contamination sources, and analytical methods.

Public concern over chemical residues in foods increased in the United States during the early 1980s. Potentially hazardous levels of ethylene dibromide (EDB), a relatively non-volatile fumigant, were detected in several finished grain-based products by governmental food-monitoring laboratories. As a result, the U.S. Environmental Protection Agency banned the use of EDB as a fumigant in 1983. Commercial fumigators then began using more of the highly volatile chemicals such as methyl bromide and phosphine. These chemicals are less likely to leave residues on stored crops than the previously used fumigants such as EDB, chloroform, and carbon tetrachloride. However, trace residues of many pest-control fumigants and related industrial chemicals are currently found in assorted foods. This contamination may come from the original fumigation of stored crops, or from the industrial chemicals occurring in the environment and in food processing chains. No potential health problem is indicated at this time. Yet scientists continue to uncover the sources of this chemical contamination, and to develop better methods to monitor foods for it. They also seek better ways to protect foodstuffs from pests prior to human consumption.

Ethylene Dibromide↗
PubMed1988

Determination of fumigants in cereals and cereal products by capillary gas chromatography.

This study describes two methods for the quantitative determination of the residual fumigants ethylene dichloride (EDC), carbon tetrachloride (CCl4), trichloroethylene (TCE), ethylene dibromide (EDB) and tetrachloroethylene (PCE) in cereals (especially wheat) and other foodstuffs. In the first method, a micro steam distillation- solvent extraction apparatus is used, while the second method is based on a headspace technique. For the quantitative determination of carbon tetrachloride in cereals, the multiple headspace technique is not retained because it is too time-consuming. The analysis of the different fumigants is performed by electron-capture gas chromatography, using a fused silica capillary column, CP sil 8 CB. With the steam distillation-solvent extraction method, recoveries from 95.9% to 100.5% are obtained for the fumigants, added at two different levels. The standard deviation varies between 1.1% and 6%. Using the simple headspace technique, recoveries from 73.5% to 85.1% with a standard deviation of between 1.7% and 6.6% have been reached for the fumigants in cereals fortified at two different levels. The absolute detection limits for the five fumigants EDC, CCl4, TCE, EDB and PCE, in both methods, are 30, 0.25, 1.1, and 0.5 pg, respectively.

Chromatography, Gas↗
PubMed1988

Toxicology and hazard evaluation of cyanide fumigation powders.

Studies were conducted to assess potential handling hazards from the pesticidal use of HCN-liberating "cyanide fumigation powders". Simulations were conducted in enclosed chambers on the release of HCN vapor from wetted powder containing 40% NaCN/60% kaolin at application rates of 1 g powder/m3 of space (usual rate) and 5 g/m3 (overuse condition). With the overuse situation, HCN vapor concentrations may be rapidly attained that produce serious or lethal toxicity; with the lower application rate minor signs and symptoms of HCN vapor exposure toxicity may develop. The acute peroral LD50 (rat and rabbit) of fumigant formulation is reduced in proportion to the kaolin content, but kaolin does not modify the inherent toxicity of NaCN. A typical cyanide hazard exists from swallowing cyanide fumigant powder formulations. Lethal systemic toxicity was produced by contamination of the eye (rabbit) with powder formulation, which also caused a rapid onset of moderately severe conjunctivitis and keratitis. Applied to dry intact skin (rabbit) neither NaCN nor its kaolin formulation produced systemic toxicity. However, on moistened intact skin lethal amounts of cyanide were absorbed; but the kaolin content reduced the hazard in comparison with NaCN-alone applied to moist skin. With abraded dry skin there was no difference in lethal toxicity between NaCN-alone and its formulation; also, the toxicity of the formulation on abraded skin was three times that on intact moist skin. These finds indicate that the use of cyanide fumigant powder formulations may be hazardous by contact of powder with moist or abraded skin, contamination of the eye, swallowing, and inhalation of evolved HCN. There is a clear need for respiratory, cutaneous, and ocular protection when handling cyanide fumigant powder formulations.

Administration, Cutaneous↗
PubMedDate not supplied

Rapid determination of fumigant and industrial chemical residues in food.

A gas chromatographic (GC) method is described for the determination of 22 fumigant and industrial chemical residues in a variety of foods. The fumigants and industrial chemicals determined are methyl bromide, methylene chloride, carbon disulfide, chloroform, 1,1-dichloroethane, ethylene dichloride, methyl chloroform, carbon tetrachloride, methylene bromide, propylene dichloride, 2,3-dichloropropene, trichloroethylene, 1,3-dichloropropylene, 1,1,2-trichloroethane, chloropicrin, ethylene dibromide, tetrachloroethylene, propylene dibromide, 1,1,2,2-tetrachloroethane, p-dichlorobenzene, o-dichlorobenzene, and 1,2-dibromo-3-chloropropane. Except for the latter three, the fumigants are determined at 90 degrees C on 3.6 m 20% loaded OV-101 columns with electron-capture and Hall-electroconductivity detectors. The other 3 compounds (o-dichlorobenzene, p-dichlorobenzene, and 1,2-dibromo-3-chloropropane), which elute beyond 30 min on the above columns, are determined at 90 degrees C on 1.8 m 5% loaded OV-101 columns with the same detectors. The ng/g-level fortifications have an overall mean analyte recovery of 70% and a coefficient of variation of 40%. The variety of foods examined includes both fatty and nonfatty food types (e.g., off-the-shelf cooked and uncooked grain-based items, dairy products, fresh and canned fruits and vegetables, and meats). Samples are extracted and cleaned up according to fat content and food type. Samples containing less than 71% fat are extracted by using an aqueous: nonaqueous shakeout (20% acetone solution under isooctane). Most extracts (isooctanes) are analyzed directly. Extracts from samples containing from 21 to 70% fat (e.g., ground beef, pecans, and corn chips) are cleaned up further on micro-Florisil columns to remove excess fat. A few other samples containing more than 71% fat or oil (e.g., butter, salad dressing, and vegetable oil) are diluted directly in isooctane and, depending on the degree of dilution, can be cleaned up further on micro-Florisil columns. Also, clear beverages (e.g., soda and tea) are extracted directly with isooctane. These extraction and cleanup techniques were tested on 231 different table-ready foods. Three-hundred incurred residues of 10 different fumigants were found in 138 items examined; 93 items had no detectable residues. The main advantage of the method is rapid semiquantitative determination of multiple fumigants from all food types.

Chromatography, Gas↗
PubMed1979

The sensitivity of some avian viruses to formaldehyde fumigation.

Various avian viruses (infectious bursal agent, reovirus, adenovirus, infectious bronchitis, Newcastle disease, poxvirus, avian encephalomyelitis and infectious laryngotracheitis virus) as suspensions in buffer or in a litter slurry were exposed to aerosolized formalin in an attempt to determine the efficacy of this fumigation method for decontamination of laboratory isolation cubicles. Formalin (37% formaldehyde) was delivered by a commercial insecticide fogger at a flow rate of 40 ml per minute and a volume of 36 ml per cubic meter of space. Fumigated cubicles were left sealed for 18 hr (cycle 1) before viruses were sampled, or were then exposed to a second fumigation and left sealed for an additional six hour period (cycle 2) before viruses were titrated (commencing at a 1:10 dilution) for residual infectivity. Although the infectivity of all viruses was reduced by over 99% by one fumigation cycle, the second cycle was necessary for reduction of Newcastle disease and reoviruses to non-detectable (no infectivity demonstrated in a 1:10 dilution of fumigated virus) levels.

Animals↗
PubMed1990

Methyl bromide intoxication in four field-workers during removal of soil fumigation sheets.

Methyl bromide is a highly toxic and penetrating compound used extensively as an insecticide for dry foodstuffs and as a soil fumigant (in greenhouses and fields) for the control of nematodes, fungi, and weeds. More than 300 cases of systemic poisoning and 60 fatalities attributable to methyl bromide have been reported [Alexeeff and Kilgore, 1983], resulting in substantial regulations concerning its handling, storage, application, and disposal. A recent exposure incident at a Connecticut nursery represents to our knowledge the first report of toxicity stemming from exposures in the field during removal of plastic sheets days after injection of methyl bromide into soil. Following removal of polyethylene sheets covering soil fumigated with methyl bromide, four field-workers developed fatigue and light-headedness and 3 workers noted progressive respiratory, gastrointestinal (GI), and neurologic symptoms. The acute systemic symptoms improved over several days, but later-onset neuropsychiatric symptoms persisted for several weeks. This incident stresses the need for improved worker education and strict adherence to safety precautions during all stages of methyl bromide fumigation and raises the possibility of an increased risk of toxicity associated with methyl bromide fumigation during a cool season.

Adult↗
PubMed1990

Preparation for human study of pesticide applicators: sister chromatid exchanges and chromosome aberrations in cultured human lymphocytes exposed to selected fumigants.

In preparation for a human study of worker exposure to grain fumigants and pesticides, we decided to screen commonly used fumigants for genotoxic effects in vitro. This research strategy was employed to test the possibility that structurally simple chemicals might have similar genotoxic properties in vivo and in vitro. As a first step, we designed our in vitro protocol to mimic to the extent possible, a single in vivo exposure of lymphocytes to fumigants. Go lymphocytes were treated with different doses of carbon tetrachloride, carbon disulfide, methyl bromide, chloropicrin, and melathion with and without addition of rat liver homogenate for 1/2 hour, washed free of toxicant, and stimulated with PHA. After culture, the prepared slides were studied for chromosome aberrations and SCEs. Malathion, methyl bromide, and chloropicrin significantly induced SCEs without S-9. Carbon disulfide alone required S-9 for significant SCE induction. Chromosome aberrations were significantly increased by malathion and methyl bromide. Carbon tetrachloride failed to induce SCEs or chromosome aberrations with or without S-9. We concluded from these preliminary studies and other comparable work that the fumigants studied here may be less likely to express genotoxicity in terms of SCEs or chromosome aberrations than ethylene oxide or phosphine given a single short-term in vivo exposure. The final design of our human study was altered to focus on seasonal worker exposure rather than on a single exposure event.

Adult↗
PubMed1990

Two-year oral chronic toxicity and carcinogenicity study in rats of diets fumigated with methyl bromide.

A chronic toxicity and carcinogenicity study was conducted by feeding diets containing 80, 200 or 500 ppm total bromine following fumigation with methyl bromide, a diet containing 500 ppm potassium bromide, or a basal diet alone to groups of 60 male and 60 female Fischer (F344) rats for up to 2 yr. Ten males and ten females from each group were killed after wk 52 and 104 for urinalysis, haematology, blood biochemistry and pathology. Rats that were killed in extremis or found dead during the study and all rats that survived to the end of the study were also subjected to pathological examinations. In rats fed the diets fumigated with methyl bromide there were no marked toxic changes, except for a slight depression of body-weight gain from wk 60 onwards in males of the 500-ppm group, and tumour incidence was unaffected. Rats given a diet containing potassium bromide did not show any treatment-related changes. It was concluded that residues of up to 500 ppm total bromine in diets fumigated with methyl bromide are not carcinogenic in F344 rats of either sex and that the maximum no-effect level is 200 ppm (6.77 mg total bromine/kg body weight/day) in males. The maximum no-effect level could not be determined in females.

Animals↗
PubMed1978

Observations on the effects of formaldehyde on cockroaches and their flora: I. Survival of vaccinia virus-infected cockroaches during fumigation with formaldehyde.

In these studies it is shown that the common "British" and "American" adult cockroaches can survive exposure to formaldehyde fumigation carried out at double the strength and for four times as long as is recommended for disinfection of rooms. It is further reported that vaccinia virus ingested prior to the fumigation survives in the cockroach gut and may be excreted up to 5 days later. Since cockroaches are ubiquitous and are to be found in most hospitals, laboratories and animal houses, these findings should be considered whenever fumigation is called for.

Animals↗
PubMed1977

Methyl bromide as a microbicidal fumigant for tree nuts.

Methyl bromide (MeBr) has broad microbicidal activity, but its use as a disinfectant for food is limited by the resulting bromide residues. Increasing the MeBr concentration, exposure temperature, or exposure period of a treatment tended to increase both the microbicidal efficacy of MeBr and the bromide residues. Its sporicidal activity was less at high than at low relative humidity within the range of 20 to 99%. Both the efficacy and the resulting residues of a MeBr treatment varied inversely with the load of product in a fumigation chamber due to sorption of the fumigant. Fumigation tests with almond kernels inoculated with Escherichia coli or Salmonella typhimurium indicated that MeBr can be used to disinfect whole nut kernels without resulting in excessive bromide residues, although the MeBr level necessary is higher than that normally used for insect control.

Anti-Bacterial Agents↗
PubMed1977

Terminal disinfection of calf houses by formaldehyde fumigation.

Trials were carried out to investigate the effectiveness of various methods of formaldehyde fumigation as a means of disinfecting calf houses. Houses were cleaned by the farmer, sealed and then fumigated. A significant reduction in bacterial numbers was obtained when the gas was produced by heating paraformaldehyde, mixing formalin with potassium permanganate or boiling formalin in calf houses that could be effectively sealed. Aerosol generators did not give satisfactory results. Efficient pre-cleaning and sealing of the houses were of paramount importance; relative humidity and temperature were less important.

Animals↗
PubMed1992

Microbiologically monitored fumigation of a newly built SPF laboratory rodent facility.

The initial sanitization and sterilization of a newly built animal facility for the breeding and holding of specific pathogen free (SPF) rats and mice is described. The fumigation programme was started with methyl bromide treatment directed primarily against arthropods, followed by ammonia spray to kill coccidial oocysts and concluded by three formaldehyde treatments with fog and spray against bacteria and viruses. The practicalities and problems involved are described in detail and the rationale and purpose of the programme and its monitoring are discussed. The report is expected to contribute towards the establishment of a rational, efficient and standardized fumigation programme for SPF animal facilities, under increasing constraints of safety and environmental considerations concerning pollution with toxic and corrosive agents.

Animals↗
PubMed1992

[Efficacy of ozone fumigation for laboratory animal sanitation].

Ozone resistance of spores of 2 strains of Bacillus isolated from laboratory animals was examined. Each of 0.02 ml of phosphate-buffered saline at pH 7.0 containing 10(6) Bacillus spores was dropped onto sterilized filter strips, wood chip bedding, pellets of diet, cloth pieces and stainless steel plates. After drying at room temperature, the test materials were exposed to ozone gas of different concentrations at 90% RH. Exposure to 200ppm ozone for 6 hours was sufficient to kill spores in filter strips, but a little higher concentration or a little longer period of ozone fumigation was necessary for sterilization of wood chips, cotton cloth pieces and steel plates. The present results indicated that 600ppm ozone fumigation for 6 hours might be effective for routine sterilization of cages, wood bedding, working clothes and other materials used in laboratory animal facilities. However, exposure to ozone gas of 500 or 1,000 ppm for 6 hours or 200 ppm for 24 hours could not kill spores in pellets of diet, suggesting that dietary protein inhibited the bactericidal activity of ozone.

Animals↗
PubMed1991

Evaluation of methyl bromide exposure on the plant quarantine fumigators by environmental and biological monitoring.

The study was undertaken to assess the potential risk of exposure to methyl bromide (MB) gas of plant quarantine fumigators who wore full facepiece gas masks with respirator canisters. The mean ambient concentrations of MB determined by a personal sampling device exceeded the TLV-ACGIH level of 5 ppm in the degassing processes at three fumigation sites except at the silos. The mean urinary bromine concentration of 379 non-MB workers was 6.3 +/- 2.5 mg/l with 95% confidence limits of 10 mg/l. There were 44.6% of 251 MB workers whose urinary bromine levels exceeded the 10 mg/l. There was a significantly positive correlation between the urinary bromine concentrations of the MB workers and the ambient MB concentrations in the degassing process. The MB levels in the workers' exhalation were positive in the degassing process, while those were below the detection limit in the dispersion process. Three possible routes through which the workers are exposed to MB gas are considered to exist: leakage through the interstice between the facepiece of a gas mask and the wearer's face, breakthrough of MB gas in the respirator canister, and percutaneous absorption of MB gas. Biological monitoring of urinary bromine and exhalatory MB as well as environmental monitoring of the ambient MB provided useful information for evaluating exposure of workers to MB.

Air Pollutants↗
PubMed1979

The metabolism of the soil fumigant 1,2-dibromo-3-chloropropane in the rat.

The soil fumigant 1,2-dibromo-3-chloropropane (I) undergoes hydrolysis in the rat to a series of epoxide metabolites. Alkylation of glutathione by these epoxides produces 2 urinary metabolites identified as the mercapturic acids VI (R=COCH3) and VII (R-COCH3). Hydrolysis of the epoxides produces the male antifertility agents alpha-chlorohydrin (IX, X-Cl) and alpha-bromohydrin (IX, X-Br) which are oxidatively metabolized to oxalic acid (XII), thus causing renal damage. These metabolic pathways can explain the toxic nature of the fumigant as a carcinogen, a male chemosterilant and as an agent causing kidney damage.

Animals↗