ACGIH

The American Conference of Governmental Industrial Hygienists, Inc., (ACGIH) deals with the protection of the health of those involved in industry. ACGIH publishes Threshold Limit Values (TLVs) for over 700 chemical substances.

Acute Effect

An effect that occurs almost immediately (hours/days) after a single or brief exposure to a toxic agent. Generally, acute effects will be evident within 14 days.

Acute Health Effect

An adverse health effect resulting from a single exposure to a substance.

Aerosols

Aerosols are airborne particulates. They may be solids or liquid droplets.

Allergy

An immune hypersensitivity reaction of body tissues to allergens that can affect the skin (urticaria), respiratory tract (asthma), gastrointestinal tract (vomiting and nausea) or produce a systemic circulatory response (anaphylactic response).

Ambient environment

The surrounding environment. This can refer to ambient air, ambient water, or ambient soil.

Anemia

A condition in which there is reduced or impaired red blood cells or hemoglobin resulting in an inadequate capacity of the blood to transport oxygen to body tissues.

Anoxia

An insufficient (below normal) supply of oxygen in the body tissues.

Antidote

A remedy for counteracting a poison.

Asphyxiant

A relatively non-toxic gas that in high concentrations in the air results in insufficient oxygen which can cause hypoxia.

Aspiration

The act of breathing in particulates or mists.

Biodegradation

Breakdown of a chemical into smaller less complex molecules by microorganisms in environmental media (e.g., soil, water, sediment).

Body Burden

The concentration of a substance which has accumulated in the body.

Bone Marrow

The tissue within the internal open space of bones (e.g., shaft of long bones) in which the blood-forming elements exist.

Cancer

An uncontrolled growth of abnormal cells, creating a tumor that can invade surrounding tissues and may spread (metastasis) to distant organs.

Carcinogen

A substance that causes or is believed to cause cancer. A carcinogenic substance is one that is known to cause cancer.

Carcinogenicity

The complex process whereby normal body cells are transformed to cancer cells.

CAS Number

Chemical Abstracts Service Registry Number is a unique identifier for a chemical and its synonyms. CAS numbers identify the chemical, but not its concentration or specific mixture.

Chronic Dose

Substance administered or received gradually over a long period of time (months to years).

Chronic Effect

An effect that either shows up a long time after an exposure (the latency period) or an effect that results from a long-term (chronic) exposure.

Chronic Health Effect

An adverse health effect resulting from long-term exposure to a substance.

Cirrhosis

A chronic condition of the liver in which liver cells are replaced by fibrous cells.

CNS

The central nervous system consisting of the brain and spinal cord.

Combustible Liquid

U.S. OSHA defines a combustible liquid as “any liquid having a flash point at or above 100 deg. F., but below 200 deg. F., except any mixture having components with flashpoints of 200 deg. F., or higher, the total volume of which make up 99 percent or more of the total volume of the mixture.”

Combustible Solid

Solids that are capable of igniting and burning.

Control Group

A group of animals or humans in a study that are treated the same as the exposed groups but without receiving the specific exposure.

Cornea

The transparent front surface of the eye.

Corrosion

Direct chemical action that results in irreversible damage at the site of contact. It is manifested by ulceration, necrosis, and scar formation.

CPSC

Consumer Product Safety Commission. It is a federal agency responsible for protecting the public from toxins and other hazards present in consumer products.

Dermal

Relating to the skin.

Dermal Toxicity

Toxicity of the skin which can range from mild irritation to corrosivity, hypersensitivity, and skin cancer.

Dermatitis

Inflammation of the skin typically marked by reddening, swelling, oozing, crusting or scaling.

Dosage

The determination of quantity of a substance received that incorporates the size, frequency, and duration of doses (e.g., 10 mg every 8 hours for 5 days).

Dose

The amount of a substance received at one time. Dose is usually expressed as administered or absorbed dose (e.g., milligrams material/kilogram of body weight).

Dose-Response Assessment

The relation between dose levels and associated effects.

DOT

Department of Transportation. A federal agency responsible for the safe shipment of toxic chemicals and other hazardous materials.

Ecologic

A term referring to the general environment.

Ecotoxicity

The toxic effects on environmental organisms other than humans.

ED50

Effective dose 50%. The estimated dose that causes some specific effect (usually desirable) for 50% of the population.

Edema

The retention of fluid in an organ or in the body.

Effluent

The discharge of waste from a plant or other source into the environment.

Environmental Fate

The fate of a substance following its release into the environment. It includes the movement and persistence of the substance.

Enzyme

A protein which serves as a catalyst for chemical reactions in cells.

Enzyme Inhibitor

A protein which serves as a catalyst for chemical reactions in cells.

A substance which causes a decrease in levels of an enzyme.

EPA

Environmental Protection Agency. A federal agency responsible for regulation of most chemicals that can enter the environment. The EPA administers the following acts: Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the Toxic Substances Control Act (TSCA), the Resource Conservation and Recovery Act (RCRA), the Safe Drinking Water Act (SDWA), Clean Air Act (CAA), and the Comprehensive Environmental Response, Compensation and Liabilities Act (CERCLA) ( Superfund Act).

Epidemiology

The study of the relative characteristics of exposed and nonexposed human populations for the purpose of detecting harmful effects.

Epidermis

The outer layer of the skin.

Excretion

A process whereby substances (or metabolites) are eliminated from the body.

Exposure

Contact with a foreign substance, usually by inhalation, ingestion, or skin contact.

Exposure Assessment

The analysis or estimation of the intensity, frequency, and duration of human exposures to an agent.

Exposure Dose

The amount of a substance in the environment to which a person is subjected.

FDA

Food And Drug Administration. A federal agency responsible for the safety evaluation of drugs, cosmetics, food additives, and medical devices.

Fetus

The unborn offspring in the postembryonic period, after major structures have been outlined. In humans this occurs from 8-9 weeks after conception until birth.

Fibrosis

The formation of scar tissue in an organ, generally by replacement of functional organ cells by non-functional fibrous tissue.

FIFRA

Federal Insecticide, Fungicide, and Rodenticide Act. A federal law, administered by the EPA, to evaluate and register pesticides.

Flash Point

Flash point is the lowest temperature at which a liquid can form an ignitable mixture in air near the surface of the liquid. The lower the flash point, the easier it is to ignite the material.

Gastrointestinal

Related to stomach and intestine.

Genetic Toxicity

Toxic effects that result from damage to DNA and altered genetic expression.

Genotoxic

Toxic effects that result from damage to DNA and altered genetic expression.

Hazard

The inherent adverse effect of a substance.

Hazard Communication Standard

An OSHA standard established in 1983 requiring all employers to inform employees of the hazard of chemicals in the workplace and the steps necessary to avoid harm.

Health Hazard

Health hazard means a chemical for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in persons exposed. The term "health hazard" includes chemicals which are carcinogens, toxic or highly toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which act on the hematopoietic system, and agents which damage the lungs, skin, eyes, or mucous membranes.

Hepatitis

Inflammation of the liver

Hepatotoxicity

Toxicity of the liver and associated bile duct and gall bladder.

Hepatotoxin

A substance that is toxic to the liver

HMIS^®, the Hazardous Materials Identification System, is a registered mark of the National Paint and Coatings Association (NPCA) but is used by all manufacturers to comply with the requirements of OSHA’s Hazard Communication Standard. HMIS^® uses colored bars, numbers and symbols to convey the severity of hazards of chemicals. Only numbers are used in this database to convey the severity of the hazards of chemical ingredients of each brand when used in the workplace. These ratings were determined for each brand by its manufacturer and documented in the Material Safety Data Sheet (MSDS) published by the manufacturer.

• “Health” denotes the health hazard. The health rating is based on the toxicity of chemicals contained in a specific brand and its ability to cause skin and eye irritation. 
• “Fire” denotes the fire hazard, and ratings are assigned based on the flashpoint and boiling point of the materials contained in a specific brand.
• “Reactivity” denotes the reactivity hazard from exposure to materials contained in the indicated brand. Reactivity ratings are based on the material’s potential to release violent energy under conditions of fire, water contact, high temperature or pressure, or proximity to activating substances.

The level of severity for acute exposures is as follows:

0 = Minimal

1 = Slight

2 = Moderate

3 = Serious

4 = Severe

N = No information provided by manufacturer

The addition of an asterisk (*) after the number indicates that exposure to chemicals in the specific brand could also pose a chronic hazard (such as emphysema or kidney damage).

Hypersensitivity

A state of altered immune reactivity in which the body reacts with an exaggerated response to a foreign agent.

Hypoxia

A partial reduction in the oxygen concentration supplied to cells or tissues.

IARC

The International Agency for Research on Cancer (IARC), an agency of the World Health Organization (WHO), compiles several databases on carcinogenic risk to humans, epidemiology and cancer control. IARC classifies chemicals and mixtures into four basic groups.  Group 1 consists of chemicals that are known to be carcinogenic to humans. Group 2A consists of chemicals that are probably carcinogenic to humans. Group 2B consists of chemicals that are possibly carcinogenic to humans. Group 3 consists of chemicals that are unclassifiable as to carcinogenicity in humans. Group 4 consists of chemicals that are probably not carcinogenic to humans.

Immunotoxicity

Toxicity of the immune system. It may take several forms: hypersensitivity (allergy and autoimmunity), immunodeficiency, and uncontrolled proliferation (leukemia and lymphoma).

In Vitro

Outside a living organism (e.g., in a test tube).

In Vivo

Occurring within a living organism.

Interactions

Refers to measures of effects of simultaneous exposure to two or more substances. The four types of interactions are: additive, antagonistic, potentiation, or synergistic.

Irritation

Local tissue reaction without involvement of an immunologic mechanism. It is a reversible inflammation.

Kilogram (kg)

A measure of weight consisting of 1000 grams (10³ g).

Latency Period

The period of time between an exposure and onset of toxicity.

LD50

Lethal Dose 50%. The estimated dose at which 50% of the population is expected to die.

LOAEL

Lowest Observed Adverse Effect Level. The lowest dose in a study in which there was an observed toxic or adverse effect.

Metabolism

The conversion of a chemical from one form to another.

Metabolite

A chemical produced when a substance is metabolized by a biological organism.

Mg/kg

A commonly used dose that stands for mg of a substance per kg of body weight.

Microgram (µg)

A commonly used unit of weight consisting of one millionth (1 x 10^-6) of a gram.

Milligram (mg)

The most commonly used unit of measure in medicine and toxicity consisting of one thousandth of a gram (1x10^-3 g).

A Material Safety Data Sheet (MSDS) is a fact sheet developed by manufacturers for all products that contain a chemical. MSDS's include brand-specific information such as physical data (solid, liquid, color, melting point, flash point, etc.), health effects, first aid, reactivity, storage, handling, disposal, personal protection and spill/leak procedures.

Nanogram (ng)

A unit of weight consisting of one billionth of a gram (1 x 10^-9 g).

Necrosis

Death, usually referring to cell death.

Nephrotoxin

A toxic agent or substance that inhibits, damages or destroys the cells and/or tissues of the kidneys.

Neurotoxin

A toxic agent or substance that inhibits, damages or destroys the tissues of the nervous system, especially neurons, the conducting cells of your body's central nervous system. Neurotoxic effects can include behavior changes, seizures, as well as wide range of effects, including death.

NIOSH

The National Institute for Occupational Safety and Health (NIOSH) is part of the Centers for Disease Control and Prevention (CDC) and is the only federal Institute responsible for conducting research and making recommendations for prevention of work-related illnesses and injuries.

NOAEL

No Observed Adverse Effect Level. The highest dose in a toxicity study at which there were no toxic or adverse effects observed.

NTP

The National Toxicology Program (NTP) is a unit of the U.S. Department of Health and Human Services that coordinates toxicology research and testing activities and provides information about potentially toxic chemicals to regulatory and research agencies and the public.

OSHA

The U.S. Occupational Health and Safety Administration, OSHA, is a federal agency in the U.S. Department of Labor that regulates workers’ exposures to hazardous substances and requires manufacturers of products containing chemicals to develop an MSDS for each brand.

Oxidation

A change in a chemical characterized by the loss of electrons.

Oxidizer

An agent that adds oxygen chemically to a substance often by means of a series of reactions.

PEL

Permissible Exposure Limit (PEL) is the maximum amount or concentration of a chemical that a worker may be exposed to under OSHA regulations.

Percutaneous

Movement through the skin.

Petroleum Distillate

Petroleum distillates, also called hydrocarbons or petrochemicals, refer to a broad range of compounds that are extracted by distillation during the refining of crude oil. Petroleum distillates pose a special health risk if ingested and vomited. When swallowed, the lighter, more volatile distillate products can be sucked into the lungs interfering with the lung's functions and chemical pneumonia may result. Aspiration of fluid into the lungs can occur both during swallowing and vomiting of the product. Upon skin contact, petroleum distillates can produce local skin irritation and sensitivity to light in some individuals.

Pharmacokinetics

Quantitation of the time course of chemical absorption, distribution, metabolism, and elimination.

Pharmacology

The science that deals with the origin, nature, chemistry, effects and uses of drugs.

Phototoxic

The enhanced toxicity of a substance in or on the skin due to exposure to light (usually ultraviolet light).

Poison

A substance capable of causing toxicity when absorbed into the body in a relatively small quantity.

PPB

Parts per billion. The number of units of a substance in a billion units. PPB is a common concentration unit for dilute samples of dissolved substances or airborne substances.

PPM

Parts per million - the number of units of a substance in a million units. PPM is a common concentration unit for dilute samples of dissolved substances or airborne substances. A solution with a concentration of 1 ppm has one gram of the substance for every million grams of solution.

Pulmonary Edema

Pulmonary edema involves fluid accumulation and swelling in the lungs.

It can be caused by direct lung injury from toxins including heat and poisonous gas, severe infection, or an excess of body fluid as seen in kidney failure.

Reproductive Toxicity

Toxicity of the male or female reproductive system. Toxic effects may include damage to the reproductive organs or offspring.

Reproductive Toxin

A reproductive toxin is a substance or agent that can cause adverse effects on the reproductive system. Exposure to reproductive toxins may cause one to become infertile or to have difficulty conceiving a child. Reproductive toxins may affect the parent, developing child (even after birth), or both.

Respiratory Toxicity

Toxicity of the upper (nose, pharynx, larynx, and trachea) or lower (bronchi, bronchioles, and lung alveoli) respiratory system.

Risk

The probability that a hazard or effect will occur at a specific level of exposure.

Sensitization

An immune capability developed following an individual's exposure to a specific antigen. Subsequent exposure results in an immune reaction.

Sensitizer

A substance that causes an allergic immune response.

Solvent

A substance that dissolves another substance to form a solution.

Syncope

Syncope, also known as fainting or swooning, is a temporary or brief suspension of consciousness due to deficiency of oxygen in the brain or sudden lowering of one's blood pressure.

Systemic toxin

A toxin that affects the entire body or many organs.

Teratogen

A compound that causes malformations in a developing fetus.

Threshold Limit Value (TLV)

A recommendation by the ACGIH for the highest level of exposure to a chemical that is safe.

Toxicant

An agent that produces adverse effects when absorbed into the body.

Toxin

A specific protein produced by certain plants, animals and microorganisms that is highly toxic to other organisms (snake venom).

TSCA

Toxic Substances Control Act. It is federal law regulating chemicals in the environment. It is administered by the Environmental Protection Agency.

Vapor Pressure

The pressure exerted when a solid or liquid is in equilibrium with its own vapor. The higher the vapor pressure the higher the volatility.

VOC’s

Volatile Organic Compounds (VOC's) are organic chemicals that have a high vapor pressure and easily form vapors at normal temperature and pressure. The term is generally applied to organic solvents certain paint additives, aerosol spray can propellants, fuels (such as gasoline, and kerosene), petroleum distillates, dry cleaning products and many other industrial and consumer products ranging from office supplies to building materials.

Volatility

The ability of a substance to change from liquid or solid form to a gaseous form.