Hazardous Materials Overview 143

acetone

A common solvent used in products like nail polish remover and cleaners. Acetone can irritate the skin and eyes and may affect breathing in high concentrations.

acids

A corrosive substance with a pH below 7 that reacts with many materials. Acids can cause skin burns, eye damage, and respiratory irritation.

administrative controls

A workplace practice or policy designed to reduce worker exposure to hazards. Administrative controls include shift rotation, training, and limiting access to hazardous areas.

air contaminants

A harmful substance present in the air, such as a gas, vapor, mist, or dust. Air contaminants may cause health problems when inhaled over time or at high concentrations.

airborne

Suspended in or carried through the air. Airborne particles such as fibers and dust can enter the respiratory system and cause illness.

alkalis

A corrosive substance with a pH above 7 that can neutralize acids. Alkalis can damage tissue and cause severe irritation or burns.

alpha rays

A type of ionizing radiation made up of two protons and two neutrons. Alpha rays can be stopped by skin or paper but are dangerous if inhaled or ingested.

ammonia

A colorless gas with a strong odor often used in cleaning products. Ammonia is an irritant that affects the eyes and respiratory system.

arsenic

A naturally occurring toxic element sometimes found in treated wood, pesticides, and contaminated water. Arsenic exposure can cause cancer and skin, lung, or heart problems.

asbestos

A naturally occurring mineral once widely used in construction and manufacturing. Asbestos fibers can cause serious lung diseases when inhaled.

asbestosis

A chronic lung condition caused by inhaling asbestos fibers. Asbestosis leads to lung scarring and difficulty breathing.

atomic particles

A basic unit of matter such as a proton, neutron, or electron. Atomic particles play a role in nuclear reactions and radiation emission.

average

A calculated central value that summarizes a range of numbers. Averages are often used to assess chemical exposure across a workday.

batteries

A device that stores and provides electrical energy through chemical reactions. Batteries may contain hazardous metals like lead, cadmium, or mercury.

bearings

A machine part that allows constrained motion between components, often rotational. Bearings may use metal alloys that include hazardous substances.

benzene

A flammable liquid used in industrial processes and as a solvent. Benzene is also toxic and is linked to serious health risks such as cancer.

beta rays

A stream of high-speed electrons or positrons emitted during radioactive decay. A beta ray can penetrate skin and is typically blocked by plastic or glass.

biological

Related to living organisms or substances derived from them. Biological hazards include viruses, bacteria, and other agents that can cause disease.

black powder

A low explosive made from a mixture of saltpeter, charcoal, and sulfur. Black powder is historically significant and still used in fireworks and small-scale blasting.

blasting agents

A type of explosive mixture that requires a booster or detonator to initiate. Blasting agents are less sensitive than high explosives and are widely used in bulk industrial operations.

bleach

A chemical commonly used as a disinfectant or cleaner. Bleach is a strong irritant that can damage skin, eyes, and lungs.

bushings

A mechanical component that reduces friction between moving parts. Bushings may contain lead or other metals for durability and lubrication.

cadmium

A toxic metal used in batteries, pigments, and metal coatings. Cadmium exposure may lead to kidney failure and bone damage.

carcinogenic

Capable of causing cancer in humans or animals. Carcinogenic materials may lead to long-term health effects even with low-level exposure.

ceiling value

The maximum concentration of a contaminant that must not be exceeded at any time. Ceiling values are set to prevent short-term exposure to dangerous levels.

cells

The smallest functional unit of a living organism. Cells can be damaged by ionizing radiation, leading to mutations or cell death.

Centers for Disease Control and Prevention

CDC. A U.S. federal agency focused on protecting public health through disease prevention and control. The Centers for Disease Control and Prevention houses NIOSH and supports workplace safety research.

chemical

Made up of specific elements or compounds with consistent properties. Chemicals may be hazardous depending on their composition and use.

coatings

A surface layer applied to protect or enhance a material. Coatings may contain hazardous metals like cadmium to improve durability or appearance.

combustible

A material that can catch fire and burn under certain conditions. Combustible substances require more heat to ignite than flammable materials.

compliance

The act of following rules, laws, or standards. Compliance with environmental regulations helps minimize the impact of hazardous materials.

concrete

A construction material made from cement, water, and aggregates like sand and gravel. Cutting or grinding concrete can release hazardous silica dust.

contaminated

Containing or carrying hazardous substances due to exposure. Contaminated items may pose a risk and often require proper disposal or decontamination.

corrosives

A substance that can destroy or irreversibly damage living tissue or materials on contact. Corrosive chemicals often cause burns to the skin, eyes, or respiratory tract.

crystalline silica dust

Fine particles released when materials containing silica are cut, drilled, or ground. Crystalline silica dust can cause long-term respiratory illnesses when inhaled.

Department of Energy

DOE. A federal agency that manages national energy policy and nuclear infrastructure in the United States. The Department of Energy is involved in nuclear weapons programs and radioactive waste management.

Department of Transportation

DOT. A federal agency that regulates transportation systems in the United States. The Department of Transportation ensures safe handling and shipping of radioactive materials.

detonators

A device used to trigger an explosive charge with precision. Detonators are essential for initiating controlled explosions in blasting operations.

disposal

The process of getting rid of waste or unwanted materials. Disposal must follow regulations to prevent harm to people and the environment.

DNA

Deoxyribonucleic acid. The molecule that contains genetic instructions in living organisms. DNA may be altered by radiation, causing mutations or health effects like cancer.

dust collection systems

An engineering control designed to capture and remove dust particles from the air. Dust collection systems reduce worker exposure to airborne contaminants like silica.

dusts

Fine, dry particles that are suspended in the air or settle on surfaces. Dust can originate from materials like wood, metal, or concrete and may pose respiratory or fire hazards depending on its composition.

dynamite

A powerful commercial explosive made from nitroglycerin absorbed in an inert substance. Dynamite is commonly used for blasting in construction and mining.

ecosystems

A community of living organisms and their physical environment functioning as a unit. An ecosystem can be disrupted by the release of hazardous materials.

engineering controls

A method that removes or reduces a hazard at its source through design or equipment. Engineering controls include ventilation systems and isolation barriers.

Environmental Protection Agency

EPA. A federal agency responsible for protecting health and the environment in the United States. The Environmental Protection Agency sets limits for hazardous materials exposure in air, water, and soil.

EPA

Environmental Protection Agency. A federal agency responsible for protecting health and the environment in the United States. The EPA sets limits for hazardous materials exposure in air, water, and soil.

ethanol

A volatile, flammable alcohol used in fuels, cleaners, and hand sanitizers. Ethanol burns easily and is considered a fire hazard in many workplaces.

explosion

A sudden, violent release of energy caused by rapid chemical reaction, often involving fire. Explosions can result from the ignition of flammable gases, vapors, or dusts.

explosive

A substance or device that releases energy rapidly through a chemical reaction, causing an explosion. Explosives are used in mining, demolition, and military applications but pose serious hazards without proper handling.

exposure

Contact between a person and a hazardous material through inhalation, ingestion, or skin absorption. Exposure can lead to health effects depending on the substance, dose, and duration.

eyewash station

A safety fixture that flushes the eyes with water to remove harmful substances. Eyewash stations are required where there is a risk of chemical exposure to the eyes.

face shields

A clear plastic guard worn in front of the face to protect against splashes or flying particles. A face shield is usually worn with other eye protection.

fiber per cubic centimeter

f/cc. A measure of how many individual fibers occupy a given volume of one cubic centimeter. Fiber per cubic centimeter is often used to assess exposure risks or material properties.

flammable

Capable of easily catching fire and burning rapidly. Flammable substances require special storage and handling.

fluorescent bulbs

A type of energy-efficient light that produces light through ionized gas. Fluorescent bulbs contain mercury and must be handled and disposed of properly.

fumes

A tiny airborne particle created by heating solid materials, such as metal or plastic. Fumes can be hazardous when inhaled and often require ventilation or respirators.

gamma rays

A high-energy electromagnetic wave emitted from an atomic nucleus. A gamma ray penetrates deeply and requires shielding with dense materials like lead.

gases

A substance in a state that expands freely to fill any space, regardless of volume. Gases may be hazardous when inhaled or when they displace breathable air.

general ventilation

The circulation of air throughout a space to dilute airborne contaminants. General ventilation improves overall air quality in a work area.

gloves

A protective covering worn on the hand to reduce skin contact with hazardous materials. Gloves must be chosen based on the type of chemical or physical hazard present.

goggles

Protective eyewear that forms a seal around the eyes to shield against splashes, dust, and fumes. Goggles offer more complete protection than standard safety glasses.

grams per cubic meter

g/m³. A unit of measurement describing the concentration of a substance in air. Grams per cubic meter is commonly used for setting limits like minimum explosive concentration.

grinding

A machining process that removes material using an abrasive surface. Grinding metal can produce harmful dust and particles.

hazard category

A sub-classification within a hazard class that indicates the severity of the hazard. Hazard categories use numbers, with Category 1 representing the most severe level.

hazard class

A broad group that describes the general nature of a physical or health hazard. Each hazardous material is assigned to a hazard class based on its primary danger.

Hazard Communication Standard

HCS. A federal regulation that requires employers to inform workers about hazardous chemicals. The Hazard Communication Standard ensures access to labels, safety data sheets, and training.

hazardous material

Hazmat. A substance that poses a risk to health, safety, property, or the environment. Hazardous material may be chemical, biological, physical, or radiological in nature.

heavy metals

A type of toxic metal with a high atomic weight or density. Heavy metals like lead and mercury can cause long-term damage to organs and systems.

high-speed electrons

An electron moving at a high velocity, often generated by radioactive decay. High-speed electrons contribute to beta radiation and can damage biological tissues.

ignite

To start burning or catch fire due to heat or flame. Ignition is a key factor in assessing the fire risk of a material.

immediately dangerous to life and health

IDLH. A level of exposure that poses an immediate threat to life, would cause irreversible health effects, or prevent escape. Immediately dangerous to life and health conditions require urgent protective action.

inflammation

A physical response by the body to injury or harmful substances, often causing redness, swelling, or pain. Inflammation is a common result of exposure to irritants.

infrared light

IR light. Electromagnetic radiation with wavelengths longer than visible light, typically experienced as heat. Infrared light is non-ionizing and not considered harmful at normal levels.

ingestion

The intake of substances through the mouth and digestive system. Ingestion of toxic metals can occur from contaminated hands, food, or surfaces.

inhalation

The act of breathing in airborne substances. Inhalation is a common route of exposure to toxic metals and dust.

ionizing radiation

Radiation that has enough energy to remove tightly bound electrons from atoms. Ionizing radiation can damage cells and DNA, leading to health risks.

irritants

A substance that causes reversible inflammation or discomfort to body tissues upon contact. Irritants may affect the skin, eyes, lungs, or mucous membranes.

irritation

A condition of discomfort or damage to body tissues due to contact with a harmful substance. Irritation is usually temporary and reversible.

isolation barriers

A physical structure used to separate people from hazardous materials or processes. Isolation barriers limit exposure by containing hazards within a designated area or shielding workers from direct contact.

isopropyl alcohol

A common flammable solvent found in disinfectants and cleaning products. Isopropyl alcohol evaporates quickly and can form explosive vapors in air.

kidney failure

A serious condition in which the kidneys lose their ability to filter waste. Kidney failure is linked to repeated or high-level exposure to certain toxic metals.

labels

A printed or written display of hazard information attached to a container. Labels include pictograms, signal words, and precautionary statements.

laryngeal cancer

A cancer that develops in the tissues of the larynx, or voice box. Laryngeal cancer has been linked to exposure to asbestos fibers.

lead

A toxic metal used in batteries, electronics, and building materials. Lead exposure can harm the brain, kidneys, and reproductive system.

local exhaust ventilation

A system that removes airborne contaminants at or near the source. Local exhaust ventilation is often used in welding, soldering, or chemical applications.

lower explosive limit

LEL. The minimum concentration of a flammable substance in air that can ignite. The lower explosive limit helps determine safe handling conditions for gases and vapors.

lung cancer

A disease in which cells in the lungs grow uncontrollably. Lung cancer is strongly associated with inhaling hazardous substances like asbestos and silica.

magazine

A secure storage facility for explosive materials. Magazines must follow strict regulations for construction, distance, and safety to prevent accidental detonation.

mercury

A toxic metal that is liquid at room temperature and used in some devices and industrial processes. Mercury can damage the nervous system and other organs.

mesothelioma

A rare and aggressive cancer affecting the lining of the lungs or abdomen. Mesothelioma is almost exclusively caused by asbestos exposure.

metal compounds

A substance made of metal combined with other elements. Metal compounds may be more reactive or harmful than pure metals in workplace settings.

metal treatments

A process used to alter the properties of metal, such as strength or corrosion resistance. Metal treatments can involve hazardous chemicals or metals.

metals

A class of solid, naturally occurring elements with high conductivity and luster. Metals are used widely in industry but can pose health risks when processed.

minimum explosive concentration

MEC. The lowest airborne concentration of a combustible dust or vapor that can cause an explosion. Minimum explosive concentration is usually measured in grams per cubic meter.

mists

Tiny liquid droplets suspended in the air, typically formed by spraying or splashing. Mists can carry hazardous chemicals and enter the body through inhalation.

mixtures

A physical combination of two or more substances that do not chemically bond. Mixtures used in explosives can include both fuel and oxidizer components.

mucous membranes

A moist tissue lining found in areas like the nose, mouth, and lungs. Mucous membranes can become inflamed or damaged by chemical exposure.

nerve damage

Harm to the nervous system that can affect sensation, movement, or function. Nerve damage may result from long-term exposure to metals like lead or mercury.

neutrons

A subatomic particle with no electric charge located in the nucleus of an atom. Neutron radiation can penetrate most materials and is common in nuclear reactors.

NIOSH

National Institute for Occupational Safety and Health. A U.S. federal agency that conducts research and makes recommendations for workplace safety. NIOSH is part of the CDC.

nuclear disintegration

The spontaneous breakdown of an unstable atomic nucleus into smaller parts. Nuclear disintegration releases radiation and can result in the formation of different elements.

Nuclear Regulatory Commission

NRC. A federal agency that oversees the safe use of radioactive materials in the United States. The Nuclear Regulatory Commission regulates nuclear energy and medical applications for that energy.

Occupational Safety and Health Administration

OSHA. A U.S. federal agency that enforces workplace safety and health regulations. The Occupational Safety and Health Administration sets standards and conducts inspections to ensure compliance.

OSHA

Occupational Safety and Health Administration. A U.S. federal agency that enforces workplace safety and health regulations. OSHA sets standards and conducts inspections to ensure compliance.

ovarian cancer

A type of cancer that begins in the ovaries. Ovarian cancer is a potential risk for individuals exposed to asbestos over time.

parts per million

ppm. A unit of measurement describing the concentration of a substance in air. Parts per million is commonly used to express gas or vapor levels in workplace air.

peak exposure limit

A short-term maximum exposure level that may exceed the ceiling value for a limited time. Peak exposure limits are tightly regulated to avoid health effects from brief, intense exposures.

permissible exposure limits

PELs. The maximum amount of a hazardous substance that a worker may be exposed to under OSHA regulations. A permissible exposure limit is legally enforceable.

personal protective equipment

PPE. Gear worn to reduce exposure to hazardous substances or environments. Personal protective equipment includes items like gloves, goggles, and respirators.

physical

Related to matter or energy that can cause bodily harm without being chemical or biological. Physical hazards include noise, heat, vibration, and mechanical force.

pigments

A substance that gives color to materials like paint, ink, or plastics. Some pigments contain toxic metals like lead or cadmium.

plating

A process of applying a thin layer of metal onto a surface. Plating often involves toxic metals such as cadmium.

PPE

Personal protective equipment. Gear worn to reduce exposure to hazardous substances or environments. PPE includes items like gloves, goggles, and respirators.

protective clothing

Garments designed to shield the body from hazardous substances. Protective clothing includes items like coveralls, lab coats, and chemical-resistant suits.

protons

A positively charged particle found in the nucleus of an atom. Protons are sometimes released during radioactive decay and can contribute to radiation exposure.

radiation

Energy transmitted through space or matter as waves or subatomic particles. Radiation can be natural or human-made and may pose health risks depending on the type and exposure level.

radio waves

A type of non-ionizing electromagnetic energy used in communication. Radio waves are not hazardous at typical exposure levels.

radioactive

Emitting energy in the form of particles or electromagnetic waves due to unstable atomic nuclei. Radioactive materials are used in medicine, energy production, and industry but require strict safety controls.

radiological

Related to materials that emit ionizing radiation. Radiological hazards can damage tissues and increase cancer risk through prolonged or high exposure.

recommended exposure limits

RELs. A suggested limit for worker exposure to a hazardous substance based on research. A recommended exposure limit is issued by NIOSH and is not legally binding.

recycling

The process of converting waste into reusable material. Recycling can reduce environmental impact and conserve natural resources.

regulations

A rule created by a government agency to enforce a law. A regulation sets specific safety or environmental requirements that individuals and organizations must follow.

respirators

A device worn over the nose and mouth or entire face to filter out harmful airborne contaminants. Respirators are selected based on the type and level of exposure.

respiratory tract

The system of organs involved in breathing, including the nose, throat, and lungs. The respiratory tract is especially vulnerable to airborne irritants and contaminants.

safety data sheets

SDSs. A detailed document that provides information about a hazardous chemical. A safety data sheet includes handling procedures, exposure limits, and first-aid measures.

safety shower

A full-body flushing system used to rinse hazardous materials from a person’s body. Safety showers are typically found in areas with chemical handling.

short-term exposure limits

STELs. The maximum concentration of a hazardous substance a worker can be exposed to for a short period, usually 15 minutes. Short-term exposure limits protect against immediate health effects from brief exposure.

silica

A mineral found in materials like sand, stone, and concrete. Silica dust becomes hazardous when inhaled during activities such as cutting or grinding.

silicosis

An incurable lung disease caused by inhaling crystalline silica dust. Silicosis results in lung scarring and increased risk of infections and cancer.

solvents

A substance that dissolves other materials to form a solution. Many solvents are irritants and may also have toxic effects.

sound waves

A vibration that moves through a medium and can be heard. Sound waves are not a form of radiation and do not damage biological tissues.

spill prevention

A set of practices used to avoid the accidental release of hazardous materials. Spill prevention helps protect human health and the environment.

switches

A device used to open or close an electrical circuit. Some older switches may contain mercury or other hazardous materials.

thermometers

An instrument used to measure temperature. Some older thermometers may contain mercury, which is toxic if released.

time-weighted average

TWA. The average level of exposure to a contaminant over a standard work shift. A time-weighted average accounts for periods of higher and lower exposure.

toxic

Harmful or deadly when inhaled, ingested, or absorbed. Toxic substances can cause short-term or long-term damage to organs and biological systems.

toxic metals

A metal that can harm human health when absorbed in significant amounts. Toxic metals may build up in the body over time and cause serious illness.

toxins

A harmful substance that can cause injury or illness. A toxin can come from chemical, biological, or environmental sources.

turpentine

A solvent made from tree resin, used in paints and varnishes. Turpentine is a strong irritant and can be harmful if inhaled or absorbed.

TWA

Time-weighted average. The average level of exposure to a contaminant over a standard work shift. A TWA accounts for periods of higher and lower exposure.

ultraviolet light

UV light. Electromagnetic radiation with wavelengths shorter than visible light. Ultraviolet light can cause skin damage and increase cancer risk with overexposure.

upper explosive limit

UEL. The maximum concentration of a flammable substance in air above which ignition will not occur. The upper explosive limit defines the top of the flammable range.

vapors

The gaseous form of a substance that is normally liquid or solid at room temperature. Vapors often result from evaporation and may be harmful if inhaled.

washers

A flat, typically round component used to distribute pressure or prevent leakage in mechanical assemblies. Washers may be made of metal or coated with materials that contain toxic metals.

waste

Unwanted or leftover materials that need to be treated or discarded. Waste from hazardous materials must be handled carefully to prevent contamination.

welding

A metal-joining process that uses high heat to melt and fuse parts. Welding can generate toxic metal fumes that must be controlled.

wildlife

Animals that live and grow in natural environments without human domestication. Wildlife can be harmed by hazardous materials through contaminated water, soil, or air.

wood preservatives

A chemical applied to wood to protect it from insects, moisture, and decay. Some wood preservatives contain arsenic or other toxic substances.

X-rays

A form of electromagnetic radiation with lower energy than gamma rays. X-rays are widely used in medical imaging and industrial inspection.