Here are some of the most frequently asked questions about health and physical hazards as well as, timely answers to them.
What are some common workplace operations that pose potential hazards?
- Hot work such as welding, soldering, brazing, melting, and burning can create dust and fumes.
- Operations with liquids such as painting, degreasing, spraying, refrigerant recharging, and wet cleaning can expose workers to mists, vapors, and splashes.
- Operations with solids (powders) that are poured and mixed may release dust and particulates that can cause irritation.
- Shaping operations such as cutting, grinding, filing, sawing, and drilling can produce dust, particulates, and fumes.
- Transfer operations in which liquid or solid chemicals are poured into small containers, can result in splashes, vapors, or airborne dust and particulates.
What are the three main health hazard concern categories?
- Routes of entry: inhalation, ingestion, injection, eye absorption or contact, skin absorption or contact
- Health hazard categories: anesthetics, asphyxiants, corrosives, irritants, sensitizers, carcinogens, mutagens, teratogens, toxics
- Target organ toxics: hepatotoxins, nephrotoxins, neurotoxins, hematopoietic toxins, pulmonary toxins, mutagens and teratogens, cutaneous toxins, optical toxins
What are routes of entry?
Inhalation: Breathing in vapors, mists, dusts, fumes, or fibers is the most common means of exposure. For example, paints, thinners, solvent-based cleaners, and welding fumes are usually inhaled.
Ingestion: Exposure occurs from eating, drinking, or hand-to-mouth contact with contaminated hands. For example, metal dusts from soldering, sanding residue, and paint can be ingested in small quantities if hands are not washed prior to eating, drinking, or smoking.
Eye absorption or contact: Splash or vapor contact can occur with hazardous materials such as strippers, solvents, or detergents. Vapors (for example, ethylene glycols in cleaners) can be absorbed through the eye into the body. Not all hazardous materials that vaporize cause skin/eye absorption health effects.
Skin absorption: Contact allows the chemicals to pass through unprotected skin cells, sweat glands, or hair follicles. Some chemicals are absorbed into the skin and bloodstream and affect organs such as the liver and kidneys.
Skin contact: Not all hazardous substances are absorbed. Some affect the skin by drying, defatting, or corroding it. Irritation, a rash, mild to severe drying of the skin, or severe burns can result. For example, paint solvents can dry the skin.
Injection: A puncture wound (injection) that comes from contaminated glass, metal, or plastic. Injection could cause symptoms similar to those experienced with skin absorption or contact.
What are the health hazard categories?
Anesthetics impair body and mind functions. Solvents and degreasers are common examples. They can make you drowsy, dizzy, nauseated, or giddy, or they can affect the thought process. They may also cause unconsciousness or, in severe cases, death.
Asphyxiants deprive the body of oxygen. Common asphyxiants are carbon monoxide and ammonia-bleach solutions. Carbon monoxide is a chemical asphyxiant that blocks oxygen exchange in the body. The resulting off-gas from a strong solution of ammonia and bleach, for example, displaces oxygen, causing respiratory distress.
Corrosives destroy body tissue, metals, plastics, and other substances. Acids, caustics, soaps, detergents, and lye are examples of corrosives. They are a contact hazard and, at times, an inhalation hazard.
Irritants cause the eyes, skin, mouth, or lungs to become dry, red, itchy, or irritated. Cleaning solvents and detergents can be irritants.
Sensitizers cause allergic reactions. Exposure to poison ivy or oak is a common example. Formaldehyde and isocyanate-based foam products can also produce sensitization. Algicides or other biological agents used in cooling towers, and common products such as baker’s yeast, can also be sensitizers.
Carcinogens cause cancer. Asbestos and cigarette smoke are known carcinogens. Constituents in gasoline (for example, benzene) are also carcinogens.
Mutagens change a gene in a sperm or egg cell. Some insecticides and pesticides are considered mutagenic hazards.
Teratogens change the embryo or fetus and are a hazard to pregnant females. Crack cocaine and radiation are known teratogens.
What is a physical hazard?
A substance is classified as a physical hazard if it ignites and burns easily, has the potential to explode, or can cause a violent reaction. Organic peroxides, oxidizers, and water-reactive substances are examples of materials that could be involved in violent reactions. A water-reactive substance is a chemical that reacts with water to release a gas or vapor that either is flammable or presents a health hazard. Physical hazards are grouped into four categories:- fire hazards
- compressed gases
- explosives
- reactive/unstable chemicals
What are fire hazards?
Fire hazards are substances that can ignite and burn easily. These substances are classified by their flash point-the lowest temperature at which a liquid will give off vapors in sufficient concentrations to ignite. Combustible liquids have flash points above 100°F but below 200°F. Pyrophoric substances ignite spontaneously in air at a temperature of 130°F or below. Flammable liquids have flash points below 100°F. Chemicals with flash points above 200°F are considered nonflammable.
What are compressed gases?
Compressed gases are contained gases with pressures greater than 40 psi (pounds per square inch). Propane cylinders and welding gases are compressed gases that may be used for building maintenance. If a container with compressed gas is not secured properly, it may fall and sustain damage. A damaged container could become a projectile and cause property damage and/or injury. Some gases are colorless and odorless. If these gases are released, they may pose a serious health hazard, because they displace oxygen or cause reactions at low-level exposures.
What are explosives?
Explosives cause a sudden, almost instantaneous release of pressure, gas, or heat. Very few, if any, explosive substances should be used for building maintenance. Some epoxy systems use materials that may be an explosive hazard if improperly used or stored.
What are reactive/unstable chemicals?
Reactive or unstable chemicals are substances that produce or release energy in the form of heat or an explosion when under pressure, exposed to light, or subjected to friction or ignition. These materials may also develop toxic or flammable vapors when mixed with water.
What are chemical incompatibilities?
Chemical incompatibilities occur when hazardous materials are inadvertently combined, producing substances that are more toxic than the original hazardous materials. When mixed together, many incompatible chemicals generate excessive heat and toxic vapors. (Pouring water into a concentrated acid is an example.) Some mixtures generate enough heat to start a fire. For instance, if petroleum products come in contact with a concentrated chlorinating agent, a fire could result. Some combinations of chemicals can actually become explosive or produce toxic gases. One of the most common accidents can occur when untrained custodial staff mix cleaners. Blending ammonia-based and bleach (chlorine)-based cleaners (for example, Mr. Clean and Clorox) in a small room or confined space can result in the release of a toxic gas (chlorine) that can be lethal within minutes. To reduce the chance of these problems properly train staff so that they understand the following rules:
- Dispose of listed hazardous materials properly.
- Store listed hazardous materials so that they do not come in contact with other chemicals.
- Do not mix anything unless you are given specific instructions, preferably from the manufacturer.
- Make sure all containers are properly labeled.
- Read and be sure you understand the information on labels and MSDSs.
- When subcontracting janitorial services to a third party, require the subcontractor to have an active hazard communication program and to supply copies of MSDSs for hazardous materials brought on-site.
This article is excerpted from BOMI Intenational’s Contaminants Reference Guide. For more information, please call 1-800-235-2664 or visit www.bomi.org.
