IDLH designation

Depending on Uie concentration, tlie effects of exposure to ainmonia gas range from mild irritation to se erc corrosion of sensitive membranes of the nose, eyes, throat, and lungs. Because of the higli solubility of ammonia in water, it is particulmly irritating to most skin surfaces. A concentration of 500 ppm has been designated as tlie IDLH immediately dangerous to life and health) concentration, wliich is based on a 30-minute exposure. Table 8.3.2 summarizes some of the relevant exposure limits for anunonia gas. 

Agent Index A045 Class Index C14 Disulfur Decafluoride No U.S. Military Designation CAS 5714-22-7 S2F10 Colorless liquid or gas with an odor of sulfur dioxide. TWA 0.025 ppm IDLH 1 ppm FC-50 LD50 — Routes Inhalation Skin Absorption (liq) Local Skin/Eye Impacts Evacuation Distances None established MW 254.1 MP -134°F BP 84°F VP 561 mmHg Vlt 740,000 ppm SG 2.08 RVD 8.8 RPr 0.008 Sol Insoluble Fl.P None IP —... 

Boron trifluoride, BFj, is a colorless gas with a vapor density of 2.34, which is heavier than air. It is water-soluble and does not support combustion. It is also water-reactive, toxic by inhalation, and corrosive to skin and tissue. The TLV is 1 ppm, and the IDLH is 100 ppm in air. The boiling point is -148°F. The four-digit UN identification number is 1008. The NFPA 704 designation is health 4, flammability 0, and reactivity 1. The primary uses are as a catalyst in organic synthesis, in instruments for measuring neutron intensity, in soldering fluxes, and in gas brazing. 

Trichloroethylene, CHCICCI2, is a stable, low-boiling, colorless liquid with a chloroform-like odor. It is not corrosive to the common metals even in the presence of moisture. It is slightly soluble in water and is nonflammable. It is toxic by inhalation, with a TLV of 50 ppm and an IDLH of 1000 ppm in air. The FDA has prohibited its use in foods, drugs, and cosmetics. The four-digit UN identihcation number is 1710. The NFPA 704 designation is health 2, flammability 1, and reactivity... 

There are two basic designs, one in which the supply of air is from a source outside the contaminated area, while in the other, the wearer of the respirator unit carries the air supply in a tank. There are also subdivisions within these two majortypes. A majorsubdivision,common to both, is whether the units operate as demand or pressure demand units. For the former, the demand valve permits the flow of air only during inhalation, and a negative pressure exists at that time within the facepiece, which may allow inward leakage from the contaminated atmosphere. The pressure-demand type maintains a positive pressure within the facepiece at all times and is unlikely to allow leakage of outside air into the respirator Pressure demand units are much more desirable and should be used in most applications. Demand units are not approved for IDLH atmospheres. 

A respiratory protection device that consists of a supply of respirable air, oxygen, or oxygen-generating material worn by the worker. It is designed for entry into and escape from atmospheres Immediately Dangerous to Life or Health (IDLH) or oxygen deficient. It is one of the highest levels of respiratory protection. Wearers carry the air supply on their back. 

IDLH TLV-TWA (ceiling exposure Umit) NIOSH recommendations Federal drinking water guidelines 25 mg/m (as CN) 4.7 ppm to 10 minutes (as CN) skin designation 4.7 ppm (hydrogen cyanide and cyanide salts) 0.2 mg/L (cyanide ion)... 

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