Human exposure liquid

Shafik TM, Bradway DE, Enos HR, et al. 1973a. Human exposure to organophosphorus pesticides A modified procedure for the gas-liquid chromatographic analysis of alkylphosphate metabolites in urine. J Agr Food Chem 21 625-629. 

In early studies, human exposure to vapor concentrations of 7-53 ppm was said to cause slight symptoms, whereas concentrations in excess of 100-160 ppm were associated with serious disturbances if inhaled for 1 hour. Rapid absorption through the intact skin is frequently the main route of entry from direct contact with either the liquid or the vapor. 

In humans, the liquid on the skin causes severe primary irritation and second-degree burns with vesiculation. Workers exposed daily at 5-10 ppm complained of irritation of the nose, throat, and eyes and, in some instances, headache and flushing of the skin of the face. Concentrations of 10-25 ppm are unpleasant and even intolerable to some subjects for exposure of more than a few minutes duration daily exposures of workers to less than 5 ppm (usually 1-2 ppm) resulted in no symptoms. ... 

Acute or chronic effects from human exposure have not been reported. In liquid form this substance may cause frostbite. 

Human subjects exposed to 2 5 ppm for 15 minutes experienced eye irritation at 50 ppm, there was also nasal irritation and a persistent unpleasant taste that remained with many subjects 3-6 hours after the exposure. Liquid mesityl oxide produces dermatitis with sustained skin contact. ... 

In industrial use, some instances of skin and respiratory tract irritation have been observed but no chronic effects have been reported. A human exposure to 12,000 ppm for 1.5 minutes in a laboratory produced nose irritation and cough mouth pipetting of the liquid caused a severe sore throat and reddened mucous membranes. Workers exposed for several hours to low vapor concentrations complained of foggy vision with rings around lights, the results of corneal edema, which cleared within 3-4 hours after cessation of exposure. ... 

In the only report involving human exposure, the liquid applied to the forearm for 1 hour and the thigh for 5 hours caused erythema, hyperemia, inflammation, and pigmentation. The volunteers experienced burning and itching at the site of application, and some blister formation occurred with the 5-hour exposures. 

Aryl halide derivatives of benzene and toluene have many uses in chemical synthesis as pesticides and raw materials for pesticides manufacture, solvents, and a diverse variety of other applications. These widespread uses over many decades have resulted in substantial human exposure and environmental contamination. Three example aryl halides are shown in Figure 1.17. Monochlorobenzene is a flammable liquid boiling at 132°C. It is used as a solvent, heat transfer fluid, and synthetic reagent. Used as a solvent, 1,2-dichlorobenzene is employed for degreasing hides and wool. It also serves as a synthetic reagent for dye manufacture. Bromobenzene is a liquid boiling at 156°C that is used as a solvent, motor oil additive, and intermediate for organic synthesis. 

Toluene is a colorless liquid boiling at 101.4°C. Gasoline is 5 to 7% toluene and is the most common source of human exposure to toluene. Toluene is one of the most common solvents inhaled by solvent abusers. It is classified as moderately toxic through inhalation or ingestion and has a low toxicity by dermal exposure. Concentrations in ambient air up to 200 ppm usually do not result... 

Although the details are beyond the scope of this book, health problems can be caused by solids and liquids suspended in water (for example, in waste-tailings streams) or in air (for example, in stack-emission plumes). Specific potential hazards have been associated with a diverse spectrum of colloidal materials, including synthetic chemicals, coals, minerals, metals, pharmaceuticals, plastics, and wood pulp. Limits for human exposure for many particulate, hazardous materials are published [504,505],... 

Additional data are needed to better define the exposure of humans and, in the context of animal toxicity studies, of laboratory animals. Because JP-8 is a complex mixture of chemicals that differ in volatility, solubility, metabolic rate and pathway, and rate and route of elimination from the body, dosimetry of critical components of the mixture at critical sites in the body is important to enhance the quality of risk assessment. The fact that human exposures can involve liquid fuel, aerosolized fuel, and vapor, by inhalation, dermal, and oral routes of exposure makes it difficult to accurately predict the internal dose of JP-8 and its components. 

Toxicity and health effects Human exposure to hydrogen bromide causes redness, pain, frostbite, and severe burns and blisters on the skin. Eye contact with the liquid causes redness, pain, severe burns, and possible permanent eye damage. It causes nose and throat irritation, watery eyes, bloody nose, nausea, vomiting, chest pain and/or light-headedness, coughing, shortness of breath, fluid in the lungs or pulmonary edema, unconsciousness, low blood pressure, rapid heartbeat, kidney failure, coma, and death. ... 

Based on animal studies, A-nitrosamines are compounds with proven carcinogenic effect. The search for sources and reduction of human exposure to their action is now one of the most important research problems. Currently, a major problem is the presence of A-nitrosamines and their precursors in food. Determination of A-nitrosamines in food relies on isolating these compounds by vacuum distillation in a basic medium, in the presence of liquid paraffin, followed by extraction with dichloromethane, pre-concentration of the sample, and analysis using GC. A thermal energy analyzer coupled to a gas chromatograph can serve as an efficient detector for these compounds. 

Because of their properties as chemically stable, viscous liquids with low electrical resistance, PCBs have been used widely in electrical equipment such as transformers and capacitors, as plasticizers, and as fluids in pumps. They have trade names such as Aroclor 1242 (which means it is a PCB which contains 42 per cent chlorine). PBBs have been used as fire retardants (see p. 258). The wide use of PCBs has led to human exposure as a result of disposal of old transformers, and so on. Their persistence means that they are detectable in the environment and in the fat and tissues of animals and humans. Their manufacture and use is now restricted, but because of their persistence they will remain in the environment for a long time. 

Different methods of human exposure assessment vary with respect to the input data or information required and the degree of uncertainty associated with resulting estimates. Eor example, the film-thickness approach to dermal exposure assessment is a screening-level methodology that assumes a uniform layer of material (e.g., a liquid consumer product) is on the skin, and that a portion of the material in this layer is absorbed, per the dermal absorption characteristics of the chemical. In contrast, dermal exposure assessment and percutaneous absorption methods can include metrics that account for time-dependent exposure and absorption processes. Eor example, in the case of secondary dermal contact with chemicals on surfaces (e.g., transfer of pesticide residues from... 

Test agent volume and method of instillation -liquids 0.1 ml in the eye Same as for Draize Liquids and solids two or more different doses within the probable range of human exposure ... 

Nitromethane is a colorless, oily liquid with a moderately strong, somewhat disagreeable odor. Production of nitromethane and its use as a solvent, fuel additive stabilizer for halogenated alkanes and intermediates, may result in its release into the environment, principally the atmosphere. Human exposure to nitromethane may additionally occur via dermal contact and accidental ingestion. 

NMP is a liquid under normal environmental conditions. Due to its low vapor pressure, human exposures are primarily limited to dermal contact. Significant inhalation exposures to NMP are possible during applications that generate NMP aerosols (e.g., graffiti removal) or vapors (e.g., unventilated cleaning baths of heated NMP). Due to its complete miscibility in water, NMP vapor concentrations in the atmosphere are limited by the relative humidity, ranging from Oppm (100% relative humidity) to 315 ppm (0% relative humidity). 

Following percutaneous exposure of bare skin to sarin vapor, the LCt5o has been estimated at llOOOmgminm for a 70kg human. For liquid percutaneous exposure, the LD50 has been estimated as 1.7 g for a 70 kg human, and for intravenous injection the LD50 has been estimated as Img for a 70 kg human. 

Tetranitromethane is an oily liquid with a vapor pressure less than that of water. It occurs as an impurity in 2,4,6-trinitrotoluene (TNT). The primary routes of potential human exposure are inhalation and dermal contact. Historically, exposure to tetranitromethane presumably occurred during the manufacture and use of TNT. 

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