safety valve, device attached to a boiler or other vessel for automatically relieving the pressure of steam before it becomes great enough to cause bursting. The common spring-loaded type is held closed by a spring designed to open the valve when the internal pressure reaches a point in excess of the calculated safe load of the boiler. Safety valves are installed on boilers according to strict safety regulations.

safety movement, widespread effort to prevent accidents that followed the increasing number of casualties in industry, traffic and transportation, and homes arising out of the Industrial Revolution and the growth of cities. Large manufacturing companies, public utilities, railroads, steamship lines, and insurance companies were particularly concerned with reducing the number of injuries and deaths as well as with cutting the cost of workmen's compensation, other damage payments, and litigation arising out of accidents. Humanitarianism and the evolution of an awareness of public responsibility were other factors in the initiation of the safety movement, which took the form of educating the public in accident prevention by way of safety clubs, posters, magazines, and other means. A vital part of the safety movement was the passing of laws, such as those requiring that buildings be constructed in accord with fire prevention laws, that automobiles meet certain basic safety requirements, that halls be well lighted in certain classes of buildings, that machinery be properly guarded, that food conform to specified standards, and that poisonous materials be so marked. In the United States the National Safety Council, founded in 1913, collects and distributes information and statistics regarding safety in industry, the home, travel, and schools. Numerous federal, state and local agencies deal with safety issues. On the federal level, the Federal Aviation Administration (founded 1958) deals with air travel; the Consumer Product Safety Commission (1972) protects the public against unsafe products; the Environmental Protection Agency (1970) regulates toxic chemicals and environmental hazards; the Food and Drug Administration (1931) regulates food, drugs, and cosmetics; the Occupational Safety and Health Administration (1970) enforces safety in the workplace; the Federal Highway Administration (1966) and the National Highway Traffic Safety Administration (1970) administer programs to increase safety on the nation's highways; the Federal Railroad Administration (1966) covers rail safety; the Mine Safety and Health Administration (1973) regulates mines; the National Transportation Safety Board (1966) investigates and regulates safety issues for all types of transportation; the Nuclear Regulatory Commission (1974) regulates nuclear power; and the Food Safety and Inspection Service (1981) inspects meat and poultry products.

safety lamp, oil lamp designed for safe use in mines and other places where flammable gases such as firedamp (see damp) may be present. Its invention (c.1816) is usually attributed to Sir Humphry Davy. The Davy lamp is based upon the principle that to be ignited a substance must first be heated to its kindling temperature and that if such heating is prevented combustion will not occur. The flame in the lamp is surrounded by a metal-gauze screen that distributes the heat over a large area so that the maximum temperature of the screen is below the ignition temperature of the flammable gas mixture (e.g., firedamp). Improvements devised by K. G. Bischof and others include special locks to prevent the accidental opening of the lamp and devices to permit the lamp to be held upside down without danger. If firedamp or related gas mixtures are present in a mine, the Davy lamp flame burns higher and with a blue halo; the height of the flame and color of the halo indicate the amount of combustible gas in the air. If the mine air is deficient in oxygen, the lamp flame is extinguished. Coal miners often placed the safety lamp close to the ground to detect gases, e.g., carbon dioxide, that are denser than air and thus collect in poorly ventilated depressions in the mine. Other gas-detecting devices are now more commonly used, e.g., the methanometer; as a light source the Davy lamp has been replaced by electric lighting.

Safety Islands: see Îles du Salut.

Occupational Safety and Health Administration (OSHA), U.S. agency established (1970) in the Dept. of Labor (see Labor, United States Department of) to develop and enforce regulations for the safety and health of workers in businesses that are engaged in interstate commerce. OSHA develops guidelines and issues regulations for safety and health standards, and conducts inspections of workplaces for compliance with these standards. In instances of noncompliance, it issues citations and proposes penalties. In the 1980s and 90s, OSHA took a more active role in protecting against health hazards in the workplace, seeking to limit the exposure of workers to hazardous substances such as lead, asbestos, pesticides, and toxic chemicals and noise.

Committee of Public Safety: see Reign of Terror.

Activities that seek to minimize or to eliminate hazardous conditions that can cause bodily injury. Occupational safety is concerned with risks in areas where people work: offices, manufacturing plants, farms, construction sites, and commercial and retail facilities. Public safety is concerned with hazards in the home, in travel and recreation, and in other situations that do not fall within the scope of occupational safety.

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Political body of the French Revolution that controlled France during the Reign of Terror. It was set up in April 1793 to defend France against its enemies, foreign and domestic. At first it was dominated by Georges Danton and his followers, but they were soon replaced by the radical Jacobins, including Maximilien Robespierre. Harsh measures were taken against alleged enemies of the Revolution, the economy was placed on a wartime basis, and mass conscription was undertaken. Dissension within the committee contributed to the downfall of Robespierre in July 1794, after which it declined in importance.

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