Vapors inhalation

Both esters have a sweet pungent odor and present a vapor inhalation ha2ard. They are rapidly absorbed through the skin and hydroly2ed to chloroacetic acid. The oral LD q for ethyl chloroacetate is between 50 and 100 mg/kg (52). 

Acute oral LD q data for nitro alcohols in mice are given in Table 1. Because of their low volatiHty, the nitro alcohols present no vapor inhalation ha2ard. They are nonirritating to the skin and, except for 2-nitro-1-butanol, are nonirritating when introduced as a 1 wt % aqueous solution in the eye of a rabbit. When 0.1 mL of 1 wt % commercial-grade 2-nitro-1-butanol in water is introduced into the eyes of rabbits, severe and permanent corneal scarring results. This anomalous behavior may be caused by the presence of a nitro-olefin impurity in the unpurifted commercial product. 

Vapor Toxicity. Laboratory exposure data indicate that vapor inhalation of alkan olamines presents low hazards at ordinary temperatures (generally, alkan olamines have low vapor pressures). Heated material may cause generation of sufficient vapors to cause adverse effects, including eye and nose irritation. If inhalation exposure is likely, approved respirators are suggested. Monoethan olamine and diethanolamine have OSHA TLVs of 3 ppm. 

Health nd Safety Factors. Thionyl chloride is a reactive acid chloride which can cause severe bums to the skin and eyes and acute respiratory tract injury upon vapor inhalation. The hydrolysis products, ie, hydrogen chloride and sulfur dioxide, are beheved to be the primary irritants. Depending on the extent of inhalation exposure, symptoms can range from coughing to pulmonary edema (182). The LC q (rat, inhalation) is 500 ppm (1 h), the DOT label is Corrosive, Poison, and the OSHA PEL is 1 ppm (183). The safety aspects of lithium batteries (qv) containing thionyl chloride have been reviewed (184,185). 

AH volatile organic solvents are toxic to some degree. Excessive vapor inhalation of the volatile chloriaated solveats, and the central nervous system depression that results, is the greatest hazard for iadustrial use of these solvents. Proper protective equipment and operating procedures permit safe use of solvents such as methylene chloride, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene ia both cold and hot metal-cleaning operations. The toxicity of a solvent cannot be predicted from its chlorine content or chemical stmcture. For example, 1,1,1-trichloroethane is one of the least toxic metal-cleaning solvents and has a recommended threshold limit value (TLV) of 350 ppm. However, the 1,1,2-trichloroethane isomer is one of the more toxic chloriaated hydrocarboas, with a TLV of only 10 ppm. 

Exposure occurs almost exclusively by vapor inhalation, which is followed by rapid absorption into the bloodstream. At concentrations of 150—186 ppm, 51—70% of the trichloroethylene inhaled is absorbed. MetaboHc breakdown occurs by oxidation to chloral hydrate [302-17-OJ, followed by reduction to trichloroethanol [115-20-8] part of which is further oxidized to trichloroacetic acid [76-03-9] (35—37). Absorbed trichloroethylene that is not metabolized is eventually eliminated through the lungs (38). The OSHA permissible exposure limit (PEL) eight-hour TWA concentration has been set at 50 ppm for eight-hour exposure (33). 

Exposure to tetrachloroethylene as a result of vapor inhalation is foUowed by absorption into the bloodstream. It is partly excreted unchanged by the lungs (17,18). Approximately 20% of the absorbed material is subsequently metabolized and eliminated through the kidneys (27—29). MetaboHc breakdown occurs by oxidation to trichloroacetic acid and oxaHc acid. 

Polymers. Studies to determine possible exposure of workers to residual epichl orohydrin and ethylene oxide monomers in the polymers have been done. Tests of warehouse air where Hydrin H and Hydrin C are stored showed epichl orohydrin levels below 0.5 ppm. Air samples taken above laboratory mixing equipment (Banbury mixer and 6" x 12" mill) when compounds of Hydrin H or C were mixed gave epichl orohydrin levels below detectable limits, and ethylene oxide levels less than 0.2 ppm, well below permissible exposure limits (46). A subacute vapor inhalation toxicity study in which animals were exposed to emission products from compounded Parel 58 suggests that no significant health effects would be expected in workers periodically exposed to these vapors (47). 

Toxicity. Low toxicity from solvent-vapor inhalation or skin contac t is preferred because of potential exposure during repair of equipment or while connections are being broken after a solvent transfer. Also, low toxicity to fish and bioorganisms is preferred when extraction is used as a pretreatment for wastewater before it enters a biotreatment plant and with final effluent discharge to a stream or lake. Often solvent toxicity is low if water solubility is high. 

Nicotine vapor inhaler Buccal Bupropion Oral tablets Clonidine Oral tablets 6-16 mg/day continuous puffing up to 10 puffs per cartridge maximum of 12 cartridges daily (approx. 120 puffs) Begin at 150 mg/day x 3-7 days then 300 mg/day in twice-per-day dosing 0.6-1.2 mg/day, 2-3 times/day... 

CIIT. 1983a. 90-Day vapor inhalation toxicity study of hydrogen sulfide in B6C3Fj mice. Report to the Chemical Industry Institute of Toxicology, Research Triangle Park, NC, by ToxiGenics, Inc. CUT docket 42063. 

Toluene Clear, colorless liquid with a slight fire hazard and moderate explosion hazard. Entry into the body is mostly by vapor inhalation. Acute and chronic exposures occur with concentrations greater than 200 ppm. Irritant to skin and eyes. 

Mattie, D.R., et al., A 90-day continuous vapor inhalation toxicity study of JP-8 jet fuel followed by 20 or 21 months of recovery in Fischer 344 rats and C57BL/6 mice, Toxicol. Pathol., 19, 77, 1991. 

Mercury vapors, inhalation of, 16 49-50 Merensky Reef platinum-group metal deposits, 19 604-607 Meridia, 3 93, 95... 

Naphthalene sodium, 22 764 preparation of, 22 778 Naphthalene sulfonates, 17 83-84 24 146 Naphthalene vapors, inhalation of,... 

Rare-earth vapors, inhalation of, 14 647 Rare gas crudes, concentration of, 17 358-360... 

Sulfur dioxide emissions, 23 666-667 Sulfur dioxide gas, 23 774 generation of, 23 771-773 production of, 23 659 Sulfur dioxide gas stream, 23 769 Sulfur dioxide vapor, inhalation of, 23 665 Sulfur dyes, 9 181-182, 242, 262-263. See also SO2 pollution... 

Cavender FL, Casey HW, Salem H, et al. 1984. A 13-week vapor inhalation study of -hexane in rats with emphasis on neurotoxic effects. Fund Appl Toxicol 4 191-201. 

Molander L, Lunell E, Andersson SB, Kuylenstierna F (1996) Dose released and absolute bioavaU-ability of nicotine from a nicotine vapor inhaler, din Pharmacol Ther 59(4) 394 00 Molander L, Hansson A, Lunell E, Alainentalo L, Hoffmann M, Larsson R (2000) Pharmacokinetics of nicotine in kidney failure, din Pharmacol Ther 68(3) 250-260 Molander L, Hansson A, Lunell E (2001) Pharmacokinetics of nicotine in healthy elderly people. Clin Pharmacol Ther 69(l) 57-65... 

Currently approved NRT products include the transdermal nicotine patch and several acute NRT products, including nicotine gum, lozenge, sublingual tablet, vapor inhaler, and nasal spray. The single-dose nicotine plasma curves for transdermal patch, gum, nasal spray, lozenge, as well oral snuff and a cigarette, are illustrated in Fig. 1 (note for the sake of simphcity, the curve for sublingual tablet is not illustrated, but because of the route of nicotine delivery, the plasma curve is qualitatively similar to nicotine gum). 

As shown in Fig. 1, the speed of nicotine uptake in venous blood following several forms of nicotine delivery varies widely, from that of the very slow pattern of nicotine appearance in the blood (several hours to peak level) produced by current transdermal nicotine medications to the explosive rise produced by tobacco smoke inhalation. Nicotine gum, lozenge, tablet, and vapor inhaler can provide more rapid delivery of nicotine than the patch, but the speed and amount obtained are constrained by use patterns. Smokeless tobacco products deliver their nicotine more rapidly than nicotine gum and with less physical effort, but are still slower than cigarettes in their nicotine dehvery. 

Molander L, LuneU E, Andersson SB, Kuylenstiema F (1996) Dose released and absolute bioavaU-abUity of nicotine from a nicotine vapor inhaler. CUn Pharmacol Ther 59 394 00 Murphy JK, Edwards NB, Downs AD, Ackerman BJ, Rosenthal TL (1990) Effects of doxepin on withdrawal symptoms in smoking cessation. Am J Psychiatry 147 1353-1357 Nabi Biopharmaceuticals (2007). Nabi biopharmaceuticals announces positive results of phase Ilb trial of NicVAX. Medical News Today, 3 May 2007. See http //www.medicalnewstoday.com/ articles/69666.php, accessed October 11, 2007... 

Schneider NG, Jarvik ME, Forsythe AB (1984) Nicotine vs, placebo gum in the alleviation of withdrawal during smoking cessation. Addict Behav 9 149-156 Schuh KJ, Schuh LM, Henningfield JE, Stitzer ML (1997) Nicotine nasal spray and vapor inhaler abuse liability assessment. Psychopharmacology 130 352-361 Schuster CR, Henningfield J (2003) Conference on abuse liability assessment of CNS drugs. Drug Alcohol Depend 70 S1-S4... 

Symptoms of exposure Vapor inhalation may cause somnolence and ataxia. Narcotic at high concentrations (Patnaik, 1992). 

Dodd, D.E., Snellings, W.M., Maronpot, R.R., and Ballantyne, B. Ethylene glycol monobutyl ether acute 9-day and 90-day vapor inhalation studies in Fischer 344 rats, Toxicol Appl. Pharmacol, 68(3) 405-414, 1983. 

The renal necrosis described in this individual resembles a renal nephropathy that was previously found only in male rats from vapor inhalation and oral exposure to JP-5 and marine diesel fuel (Bruner 1984 Cowan and Jenkins 1981 Gaworski et al. 1984 Parker et al. 1981). There are data that show the j.-globulin protein, which is responsible for the necrosis in rats, may not exist in humans (Alden 1986). 

Calhoun RA, Dittenber DA, Lomax LG, et al Chlorpyrifos A 13-week nose-only vapor inhalation study in Fischer 344 rats. Eundam Appl Toxicol 13 616-618, 1989... 

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