Nitrogen dioxide hazard

Reference methods for criteria (19) and hazardous (20) poUutants estabHshed by the US EPA include sulfur dioxide [7446-09-5] by the West-Gaeke method carbon monoxide [630-08-0] by nondispersive infrared analysis ozone [10028-15-6] and nitrogen dioxide [10102-44-0] by chemiluminescence (qv) and hydrocarbons by gas chromatography coupled with flame-ionization detection. Gas chromatography coupled with a suitable detector can also be used to measure ambient concentrations of vinyl chloride monomer [75-01-4], halogenated hydrocarbons and aromatics, and polyacrylonitrile [25014-41-9] (21-22) (see Chromatography Trace and residue analysis). 

Minor and potential new uses include flue-gas desulfurization (44,45), silver-cleaning formulations (46), thermal-energy storage (47), cyanide antidote (48), cement additive (49), aluminum-etching solutions (50), removal of nitrogen dioxide from flue gas (51), concrete-set accelerator (52), stabilizer for acrylamide polymers (53), extreme pressure additives for lubricants (54), multiple-use heating pads (55), in soap and shampoo compositions (56), and as a flame retardant in polycarbonate compositions (57). Moreover, precious metals can be recovered from difficult ores using thiosulfates (58). Use of thiosulfates avoids the environmentally hazardous cyanides. 

Prevent air contamination in high-pressure reactions since the nitrogen dioxide which could form may pose ignition and detonation hazards. 

From the above it can be concluded that the risk for lung cancer induction from chronic indoor exposure to Rn-d is unlikely to be higher than 1.10 4/mSv. in order to understand the magnitude of this risk it has to be emphasized that man can be exposed to a multitude of different hazardous materials in the indoor atmosphere besides Rn-d, such as formaldehyde, nitrogen dioxide, carbon monoxide, nitrosamines, polyaromatic hydrocarbons, volatile organic compounds, asbestos and pesticides (Gammage and Kaye, 1985). 

Fuming nitric acid is concentrated acid that contains dissolved nitrogen dioxide. It is a colorless, yellow, or red fuming liquid with an acrid, suffocating odor. Fumes are primarily nitrogen dioxide. This material is hazardous through inhalation, and ingestion, and produces local skin/eye impacts. 

Colorless gas that becomes reddish-brown in high concentrations. It has a sharp, suffocating, sweet odor. This material is hazardous through inhalation and produces local skin/eye impacts. It is rapidly converted in air to nitrogen dioxide. 

AEGL values for nitrogen dioxide should be used for emergency planning. Short-term exposures below 80 ppm of nitric oxide should not constitute a health hazard. 

Further warning as to expln hazard of dry acetyl peroxide with recommended precautions) 63)F.H.Pollard P.Woodward, Tr-FaradSoc 45, 767-70 (1949) CA 44, 25 (1950) (Expl reaction of formaldehyde nitrogen dioxide) 63a)L.Medard, MP 31, 273-85 (1949) ... 

Action of heat on nitrates. For safety reasons this is best demonstrated as there are some serious hazards - molten potassium and sodium nitrates/ nitrite, decrepitation with lead nitrate and the emission of the poisonous gas, nitrogen dioxide. 

Industrial hazards There are many man-made agents, industrial gases and volatile liquids that constitute hazards in terms of accidental exposure, e.g. various aldehydes (formaldehyde, glutaraldehyde), sulphur dioxide, ammonia, nitrogen dioxide etc.). An industrial irritant agent much studied recently is toluene diisocyanate, which potently evokes the signs of neurogenic inflammation. 

Chemical absorption in scrubbers, which employ any of water, nitric acid, alkaline solutions, or solutions of urea in water can reduce tail gas NOx concentrations to below 200 ppm [55]. Physical adsorption on molecular sieves is also a feasible control method. Activated carbon cannot be used because of oxidation hazards. Chemical and physical adsorption were improved if both nitric oxide and nitrogen dioxide were present in the tail gas rather than just nitric oxide, perhaps from the formation of dinitrogen trioxide (N2O3). An advantage of any absorption or adsorption system is that the NOx collected is recovered in some form. 

CAUTION Nitrogen dioxide and dinitrogen pentoxide are extremely toxic and hazardous substances. All diazo compounds and particularly nitrodiazo compounds are potentially toxic and explosive. Ni-trodiazoacetic acid and nitrodiazomethane are extremely explosive. A face shield and heavy gloves should be worn when working with these compounds. 

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