Exposure to vapors

Full eye protection should be worn whenever handling acryhc monomers contact lenses must never be worn. Prolonged exposure to Hquid or vapor can result in permanent eye damage or blindness. Excessive exposure to vapors causes nose and throat irritation, headaches, nausea, vomiting, and dizziness or drowsiness (solvent narcosis). Overexposure may cause central nervous system depression. Both proper respiratory protection and good ventilation are necessary wherever the possibiHty of high vapor concentration arises. 

In normal practice, good ventilation to reduce exposure to vapors, splash-proof goggles to avoid eye contact, and protective clothing to avoid skin contact are required for the safe handling of acrylic monomers. A more extensive discussion of these factors should be consulted before handling these monomers (67). 

Health and Safety. Both N-methylpyrrohdinone and dibasic esters have very low vapor pressure which limits worker exposure to vapors. Manufacturers recommend that the same safety precautions be taken as with other organic solvents. Ha2ardous location requirements must be considered if the formula is flammable. Ventilation that reduces vapors to manufacturer s recommended exposure levels should be used. 

Health and Safety Factors. The Material Safety Data Sheets provided by the suppUers should be consulted for each product. In general, products are aqueous emulsions with low levels of toxicity. Products with high solvent content have mostly been eliminated. Personnel handling the chemicals should always avoid contact of the products with skin and eyes, and avoid exposure to vapors if the product contains volatile components. 

Eor deicing fluid appHcations, exposure to vapors and mists is the more likely means of exposure. Ethylene glycol has a threshold limit value (TLV) of 50 ppm for vapors. When proper deicing procedures are foUowed and proper protective equipment worn, the exposure of deicing personnel to vapor and mist is expected to fall weU below this TLV value. This mode of exposure is unlikely for engine cooling appHcations. 

Overexposure to tetrachloroethylene by inhalation affects the central nervous system and the Hver. Dizziness, headache, confusion, nausea, and eye and mucous tissue irritation occur during prolonged exposure to vapor concentrations of 200 ppm (15). These effects are intensified and include incoordination and dmnkenness at concentrations in excess of 600 ppm. At concentrations in excess of 1000 ppm the anesthetic and respiratory depression effects can cause unconsciousness and death. A single, brief exposure to concentrations above 6000 ppm can be immediately dangerous to life. Reversible changes to the Hver have been reported foUowing prolonged exposures to concentrations in excess of 200 ppm (16—22). Alcohol consumed before or after exposure may increase adverse effects. 

The vapors of aHyl chloride are very irritating to the eyes, nose, and throat. Lung injury may be delayed in onset. Liver and kidney injury can result from exposure to vapors kidney injury is expected to be most severe in acute exposures. High concentrations of vapor can be lethal. FoHowing chronic exposures to the vapors, Hver injury would be expected to occur first (23). 

Dowtheim J (Dow Corning Coi poration). A mixture of isomers of an alkylated aromatic recommended temperature range —70°C to 300°C noncorrosive toward steel, common metals and alloys combustible material flash point 58°C low toxic prolonged and repeated exposure to vapors should be limited 10 ppm for daily exposures of eight hours. 

Toxicity. It is a lacrymator and irritates the skin mucous membranes, especially of the respiratory tract (Ref 26). Prolonged exposure to vapors causes damage to liver, kidneys, and other organs. Concn in air of 0.1 ppm is fatal and 3.3ppm or higher are rapidly fatal (Ref 47, p 1156). Its threshold limit value in air is set at lppm (Ref 47, p 22)... 

Evaluation of chromatograms la 133ff Evaluation, peak area or height la 31,33,40 -, optical trains la 30, 39 Evipan la 339,343 Excitation to fluorescence la 10,12,20,37 Explosion resulting from reagent residues la 82,253,261,315,365 Explosives lb 49,244,407-409 Exposure to vapors la 86... 

Very low. Even very small, repeated exposures of HD are cumulative in their effects or more than cumulative owing to sensitization. This has been shown in the postwar case histories of workers in mustard-filling plants. Exposure to vapors from spilled HD causes minor symptoms, such as "red eye." Repeated exposure to vapor causes 100% disability... 

All the work we describe in this chapter was carried out in UHV on the rutile Ti02(l 1 0)1 x 1 surface. Exposures to vapors and gases are given in Langmuirs (L) where 1 L = 1.333 x 10 s mbar s. Coverages of defects or molecules adsorbed at the surface will be given in monolayers (ML), where 1 ML corresponds to the density of primitive surface unit cells. 

Organic Lead. Following a single exposure to vapors of tetraalkyl lead compounds (approximately 1 mg/m3 breathed through a mouthpiece, 10-40 breaths of approximately 1 L volume) in four male subjects, 37% and 51% of inhaled tetraethyl and tetramethyl lead, respectively, were initially found in the respiratory tract, but a considerable percentage of these volatile compounds was lost through exhalation (Heard et al. 1979). Approximately 60-80% of the deposited tetraalkyl lead was absorbed by the lungs. 

Fig. 4.12 Dynamic response profiles at different wavelengths upon replicate (n 3) exposures to vapors at 0.02 P/Pq concentration (a) water, (b) ACN, (c) DCM, and (d) toluene. Wavelengths 770 nm circles), 835 nm squares), and 870 nm diamonds). Reprinted from Ref. 15 with permission. 2008 Institute of Electrical and Electronics Engineers...

Nerve agent intoxication requires rapid decontamination to prevent further absorption by the patient and to prevent exposure to others, ventilation when necessary, administration of antidotes, as well as supportive therapy. Skin decontamination is not necessary with exposure to vapor alone, but clothing should be removed to get rid of any trapped vapor. With nerve agents, there can be high airway resistance due to bronchoconstric-tion and secretions, and initial ventilation is often difficult. The restriction will decrease with atropine administration. Copious secretions which maybe thickened by atropine also impede ventilatory actions and will require frequent suctioning. For inhalation exposure to nerve agents, ventilation support is essential. 

HD vapors are heavier than air and tend to seek lower elevations. HD is slightly soluble in cold water and soluble in most organic solvents. Exposure in any concentration will cause severe choking. Exposure to vapors in low to moderate concentrations will cause temporary blindness and inflammation of the entire respiratory tract. Higher concentrations cause permanent blindness and strip the bronchial tubes of their mucus membrane linings. 

Musculoskeletal Effects. A case of muscle pain and weakness was described in an individual after intermittent chronic inhalation and dermal exposure to vapors and solutions of phenol, cresol, and xylenol (Merliss 1972). The symptoms lessened when the subject was removed from exposure. 

Hepatic Effects. Enlarged liver and elevated serum levels of hepatic enzymes indicative of liver injury (lactate dehydrogenase, 2 times above normal aspartate aminotransferase, 21 times above normal alanine aminotransferase, 100 times above normal) were observed in an individual following chronic daily exposure to vapors and spills of phenol (Merliss 1972). The symptoms lessened when the... 

Renal Effects. In a case of chronic phenol poisoning, dark urine and glucose in the urine were noted in a man following intermittent exposure to vapors and solutions of phenol (Merliss 1972). The urine tested negative for protein and urobilinogen. The urine cleared 2-3 months after removal from exposure. Although the exposure concentrations were not reported, the study author stated that heavy odors were often detectable, and that phenol was often spilled on the patient s clothes resulting in skin irritation. Since phenol is absorbed readily from the skin, dermal absorption may have contributed to the systemic effects that were observed. 

Symptoms of exposure Exposure to vapors may cause eye and respiratory tract irritation (Patnaik, 1992). 

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