Inhaled irritants

Sihcon carbide has been described as a mild inhalation irritant (143). The threshold limit value for siUcon carbide in the atmosphere is 5 mg/m. Because of increased interest in SiC whiskers as a reinforcement for composites, the ASTM has estabUshed Subcommittee E34.70 on Single-Crystal Ceramic Whiskers to write standards for handling this form of SiC (144). 

Health Hazards Information - Recommended Personal Protective Equipment Acid-vapor-type respiratory protection rubber gloves chemical worker s goggles other equipment as necessary to protect skin and eyes Symptoms Following Exposure Inhalation irritates mucous membranes. Contact with liquid causes severe bums of eyes and skin. Ingestion causes severe burns of mouth and stomach General Treatment for Exposure Get medical attention following all Exposures to this compound. 

Because the mucus layer or the underlying cells may serve as either final accumulation sites of toxic gases or layers through which the gases diffuse en route to the blood, we need simplified models of these layers. Altshuler et al. have developed for these layers the only available model that can be used in a comprehensive system for calculating tissue doses of inhaled irritants. It assumes that the basement membrane of the tracheobronchial region is covered with three discrete layers an inner layer of variable thickness that contains the basal, goblet, and ciliated cells a 7-Mm middle layer composed of waterlike or serous fluid and a 7-Mm outer layer of viscous mucus. Recent work by E. S. Boatman and D. Luchtel (personal communication) in rabbits supports the concept of a continuous fluid layer however, airways smaller than 1 mm in diameter do not show separate mucus and serous-fluid layers. 

Effects of Inhaled Irritants and Airway Abnormalities on Air and Mucus Flow... 

Fairchild, E. J., II. Neurohumoral factors in injury from inhaled irritants. Arch Environ. Health 6 79-86, 1%3. 

Dibenzylamine 0.20 g, 1.0 mmol harmful if swallowed, skin irritant, may be an inhalation irritant... 

Silica gel 2.0 g harmful if inhaled, irritant, chronic exposure to the dust may be very harmful... 

The lining of the vestibule, which contains a zone of short stiff hairs (vibrissae), acts as a baffle system for filtering out large (>10 pm) airborne particles. The stratified squamous epithelium of the vestibule is resistant to dehydration and inhaled irritants and poorly permeable. Between the vestibule and atrium, there is a constriction known as the internal... 

Toxic by inhalation. Irritating to the skin, eyes, and mucous membranes. Causes garlic breath, dizziness, and nausea. Can cause damage to the lungs and liver as well as conjunctivitis, and is an allergen.1,2 TLV-TWA (Se) 0.05 ppm (0.16 mg/m3).4... 

Airflow obstruction in asthma is due to bronchoconstriction resulting from contraction of bronchial smooth muscle, inflammation of the bronchial wall, and increased mucous secretion. Asthmatic attacks may be related to recent exposure to allergens, inhaled irritants leading to bronchial hyperactivity and inflammation of the airway mucosa. The symptoms of asthma may be effectively treated by several drugs, but none of the agents provide a cure for this obstructive lung disease. 

Erskine et al. (1993) measured the threshold concentration of ammonia required to elicit reflex glottis closure, which is a protective response stimulated by inhaling irritant or noxious vapors at concentrations too small to produce cough. Glottis closure was measured in 102 healthy nonsmoking subjects between the ages of 17 and 96. The results showed a strong correlation between age... 

Ronzani, E. 1909. Concerning the influence of inhaling irritating industrial gases on the strength of the body s defenses against infectious disease. Arch. F. Hyg. 70 217-269. 

An American Red Cross first-aid handbook should be part of your laboratory equipment. Refer to it in case of accident, and never hesitate to call a doctor if you are accidentally burned or inhale irritating fumes. 

The solid can cause serious eye injury, it is a skin and inhalation irritant, and it can be fatal if swallowed. 

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