Term

Definition

Action level

A concentration designated in Title 8, California Code of Regulations for a specific substance, calculated as an eight-hour time-weighted average, that initiates certain required activities such as exposure monitoring and medical surveillance

Acute effect

Symptom of exposure to a hazardous material that appears soon after a short-term exposure, coming quickly to a crisis

Acute exposure

A single, brief exposure to a large dose of a toxic substance. Adverse health effects are evident soon after exposure.

Acute toxicity

Adverse biological effects of a single dose of a toxic agent

Aerosol

A suspension of fine solid or liquid particles in air (e.g., paint spray, mist, fog)

Allergen

A type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body

American Conference of Governmental Industrial Hygienists (ACGIH)

A voluntary membership organization of professional industrial hygiene personnel in governmental or educational institutions. The ACGIH develops and publishes recommended occupational exposure limits each year called threshold limit values (TLVs) for hundreds of chemicals, physical agents, and biological exposure indices (BEIs) to assess worker exposure.

American National Standards Institute (ANSI)

A privately funded, voluntary organization that develops standards for the safe design and operation of equipment and safe practices or procedures for industry

Anesthetic

A chemical that causes drowsiness. Large doses of anesthetic chemicals can cause unconsciousness, coma, and death.

Asphyxiant

A chemical vapor or gas that replaces air and can cause death by suffocation. Asphyxiants are especially hazardous in confined spaces.

Biological exposure index (BEI)

Guidance values established by the ACGIH for assessing biological monitoring results from specimens (such as urine or blood). A BEI is an index of an individual’s uptake of a chemical specimen collected from a healthy worker who has been exposed to chemicals to the same extent as workers with inhalation at the TLV.

Boiling point

The temperature at which the vapor pressure of a liquid equals atmospheric pressure or at which the liquid changes to a vapor. The boiling point is usually expressed in degrees Fahrenheit. If a flammable material has a low boiling point, it indicates a special fire hazard.

Carcinogen

A chemical or physical agent that is known or suspected to cause neoplasms (tumors) in humans and/or animals. See “Select carcinogen” in the glossary for criteria to determine the carcinogenic potential of chemicals.

Cardiac

Refers to the heart

CAS Registry number

Identifies a particular chemical by a number assigned by the Chemical Abstracts Service, a service of the American Chemical Society that indexes and compiles abstracts of worldwide chemical literature called Chemical Abstracts

cc

Cubic centimeter. A metric-system volume measurement equal to a milliliter (ml). One quart is about 946 cc (946 ml).

Ceiling limit

The maximum allowable exposure limit for an airborne chemical, which is not to be exceeded even momentarily. See also PEL and TLV.

Central nervous system

The part of the body made up of the brain, spinal cord, and nerves

Chemical

As broadly applied to the chemical industry, an element or a compound produced by chemical reactions on a large scale for either direct industrial and consumer use or for reaction with other chemicals

Chemical family

Chemicals with similar structural characteristics are grouped into a chemical family (e.g., ketones, alcohols, hydrocarbons)

Chemical Hygiene Officer

A person designated by the employer who is qualified, by training or experience, to provide technical guidance in the development and implementation of the provisions of the Chemical Hygiene and Safety Plan

Chemical Hygiene Plan (CHP)

A written program developed and implemented by the employer, which sets forth procedures, equipment, personal protective equipment and work practices that are capable of protecting employees from the health hazards presented by hazardous chemicals used in the particular workplace.

Chemical Hygiene and Safety Plan (CHSP)

The written Web-based program developed by Berkeley Lab to comply with the Cal/OSHA Laboratory Standard. The CHSP addresses all elements of the Cal/OSHA-mandated Chemical Hygiene Plan and provides further information specific to Berkeley Lab.

Chemical Management System (CMS)

LBNL’s site-wide chemical inventory for providing chemical users, EHS staff, and emergency response teams accurate and up-to-date lists of chemicals stored on site.

Chemical reaction

A change in the arrangement of atoms or molecules to yield substances of different composition and properties (see reactivity)

Chronic effect

Symptom of exposure to a hazardous material that develops slowly after many exposures or that recurs often

Chronic exposure

Repeated exposure or contact with a toxic substance over a long period. Adverse biological effects from chronic exposure develop slowly, last a long time, and frequently recur.

Chronic toxicity

Adverse biological effect of repeated doses or long-term exposure to a toxic agent

Combustible

A substance that will burn

Combustible liquid

Any liquid having a flashpoint at or above 100°F (37.8°C), but below 200°F (93.3 °C), except any mixture having components with flashpoints of 200°F (93.3°C), or higher, the total volume of which make up 99% or more of the total volume of the mixture

Concentration

The relative amount of a given substance present when mixed with another substance(s). Concentration is often expressed as parts per million (ppm), percent, or weight per unit volume, e.g., milligrams/cubic meter (mg/m3).

Corrosive

A chemical that causes visible destruction of or irreversible changes in living tissue by chemical action at the site of contact, or that has a severe corrosion rate on structural materials

Decomposition

The breakdown of a material into simpler compounds by chemical reaction, decay, heat, or other processes

Density

The mass of a substance per unit volume. The density of a liquid is usually compared with water, which has a unit density of 1; the density of a gas is usually compared with air. Substances that float on water have densities of less than 1; substances that sink in water have densities greater than 1.

Department of Transportation (DOT)

The U.S. federal agency that regulates the labeling and transportation of hazardous materials

Dermal

Refers to the skin

Dermatitis

An inflammation of the skin that can be caused by irritation (chemical, physical, or mechanical) or allergic reaction

Designated area

An area that may be used for work with particularly hazardous substances including select carcinogens, reproductive toxins, or substances that have a high degree of acute toxicity. A designated area may be the entire room, an area within a room, or a device such as a fume hood or glove box.

Dilution ventilation

See general ventilation.

Dose

The amount of a substance received during exposure. See mg/kg.

Dyspnea

Shortness of breath; difficult or labored breathing

Environment, Health, and Safety Division (EHS)

Berkeley Lab’s Environment, Health, and Safety Division

Epidemiology

The branch of medical science that deals with the incidence, distribution, and control of disease in a population

Erythema

A reddening of the skin

Evaporation rate

The rate at which a material is converted to vapor (evaporates) at a given temperature and pressure when compared with the evaporation rate of a reference material (e.g., butyl acetate). Health and fire hazard evaluations of materials involve consideration of evaporation rates as one aspect of the evaluation.

Explosive

A chemical that causes a sudden, almost instantaneous release of pressure, gas, and heat when subjected to sudden shock, pressure, or high temperature

°F

Degrees, Fahrenheit; a temperature scale

Flammable

A chemical that falls into one of the following categories:

• "Aerosol, flammable" is an aerosol that, when tested by the method described in 16 CFR 1500.45, yields a flame projection exceeding 18 inches at full valve opening, or a flashback (a flame extending back to the valve) at any degree of valve opening
• “Gas, flammable" is a material that is a gas at 68°F (20°C) or less at 14.7 pounds per square inch atmosphere (psia) (101 kPa) of pressure (a material that has a boiling point of 68°F (20°C) or less at 14.7 psia [101 kPa]) which:

• Is ignitable at 14.7 psia (101 kPa) when in a mixture of 13% or less by volume with air; or
• Has a flammable range at 14.7 psia (101 kPa) with air of at least 12%, regardless of the lower limit

The limits specified shall be determined at 14.7 psi (101 kPa) of pressure and a temperature of 68°F (20°C) in accordance with ASTM E 681.

• "Liquid, flammable" means any liquid having a flashpoint below 100°F (37.8°C), except any mixture having components with flashpoints of 100°F (37.8°C) or higher, the total of which make up 99% or more of the total volume of the mixture
• "Solid, flammable" means a solid, other than a blasting agent or explosive as defined in 1910.109(a), that is liable to cause fire through friction, absorption of moisture, spontaneous chemical change, or retained heat from manufacturing or processing, or that can be ignited readily and when ignited burns so vigorously and persistently as to create a serious hazard. A chemical is considered to be a flammable solid if, when tested by the method described in 16 CFR 1500.44, it ignites and burns with a self-sustained flame at a rate greater than one-tenth of an inch per second along its major axis.

Flammable liquid

A liquid having a flashpoint below 100°F (37.8°C), except any mixture having components with flashpoints of 100°F (37.8°C) or higher, the total of which make up 99% or more of the total volume of the mixture

Flash point

The minimum temperature at which a liquid gives off a vapor in sufficient concentration to ignite

Formula, chemical

A representation of a substance using symbols for its constituent elements: Water is H2O; hydrochloric acid is HCl.

Fume hood

A ventilation device composed of an enclosure on five sides with a movable sash on the remaining side. Fume hoods are constructed and maintained to draw air from the open side in order to prevent or minimize the escape of air contaminants into the work area. This device allows chemical manipulations to be conducted in the enclosure without insertion of any portion of the employee’s body other than hands and arms.

g/kg

See grams per kilogram.

General ventilation

Also known as general exhaust ventilation and dilution ventilation. Fresh air mixes with contaminants in the workroom air and is then exhausted (see local exhaust ventilation)

GHS -Globally Harmonized System of Classification and Labelling

A standardized method to classify chemical hazards to communicate them through Safety Data Sheets (SDS) and container labels. GHS is intended to be used worldwide. The system has been adopted by the Cal/OSHA Hazard Communication Standard.

Gram (g)

A metric unit of weight. One ounce equals 28.4 grams.

Grams per kilogram (g/kg)

The dose of a substance given to test animals in toxicity studies. For example, a dose may be 2 grams (of substance) per kilogram of body weight (of the experimental animal).

Hazard warning

The words, pictures, and symbols, or combinations thereof, that appear on a label and indicate the hazards of the substance in the container

Hazardous chemical

A hazardous chemical is any chemical classified as a health hazard or a physical hazard:

Health Hazard:  is a chemical posing one of the following hazardous effects: acute toxicity (any route of exposure); skin corrosion or irritation; serious eye damage or eye irritation; respiratory or skin sensitization; germ cell mutagenicity; carcinogenicity; reproductive toxicity; specific target organ toxicity (single or repeated exposure); or aspiration hazard.

Physical Hazard: is a chemical posing one of the following hazardous effects: explosive; flammable (gases, aerosols, liquids, or solids); oxidizer (liquid, solid or gas); self-reactive; pyrophoric (liquid or solid); self-heating; organic peroxide; corrosive to metal; gas under pressure; or in contact with water emits flammable gas.

Hazardous material

Any substance or compound that has the capability of producing adverse effects on the health and safety of humans. This term is used interchangeably with hazardous chemical.

Health hazard

A health hazard is a chemical posing one of the following hazardous effects: acute toxicity (any route of exposure); skin corrosion or irritation; serious eye damage or eye irritation; respiratory or skin sensitization; germ cell mutagenicity; carcinogenicity; reproductive toxicity; specific target organ toxicity (single or repeated exposure); or aspiration hazard

Health and Safety Representative

An EHS Division industrial hygienist or safety professional assigned to provide support to research or operation divisions.

Hematopoietic system

The blood-forming organs of the body, including bone marrow and the spleen

Hepatotoxin

A chemical that can cause liver damage (e.g., carbon tetrachloride)

Highly toxic chemical

A chemical falling within any of the following categories:

• A chemical that has a median lethal dose (LD50) of 50 milligrams or less per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each
• A chemical that has an LD50 of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) on the bare skin of albino rabbits weighing between 2 and 3 kilograms each
• A chemical that has a median lethal concentration (LC50) in air of 200 parts per million by volume or less of gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each

Ignitable

A solid, liquid, or compressed gas that has a flashpoint of less than 140°F

Ignition temperature

The lowest temperature at which a substance will ignite and continue to burn. The lower the ignition temperature, the more likely the substance is to be a fire hazard.

Incompatible

The term applied to two substances to indicate that one material cannot be mixed with the other without the possibility of a dangerous reaction

Ingestion

Taking a material into the body through the mouth and swallowing it

Inhalation

Breathing in of airborne substances that may be in the form of gases, fumes, mists, vapors, dusts, or aerosols

Inhibitor

A substance added to another to prevent an undesirable chemical reaction

International Agency for Research on Cancer

( IARC )

Publishes monographs on the evaluation of the carcinogenic risk of chemicals to humans, which are used to determine the cancer risk of a chemical

Irritant

A non corrosive chemical that causes a reversible inflammatory effect on living tissue including the skin, eyes, nose, or respiratory system by chemical action at the site of contact. A chemical is a skin irritant if, when tested on the intact skin of albino rabbits by the methods of 16 CFR 1500.41 for four hours exposure or by other appropriate techniques, it results in an empirical score of five or more. A chemical is an eye irritant if so determined under the procedure listed in 16 CFR 1500.42 or other appropriate techniques.

Lacrimation

Abnormal or excessive production of tears as a result of exposure of the eyes to an irritant

Lethal concentration 50

(LC50)

The concentration of a substance in air that will kill half (50%) of the exposed test animals. A measure of acute toxicity.

Lethal dose 50 (LD50)

The dose of a substance that will kill half (50%) of the treated test animals when given as a single dose. A measure of acute toxicity.

Local exhaust ventilation

A ventilation method for removing contaminated air at the point where the contaminants are generated (e.g., a fume hood)

Lower explosive limit (LEL)
or
Lower flammable limit (LFL)

The lowest concentration of a substance that will produce a fire or flash when an ignition source (flame, spark, etc.) is present. It is expressed in percent of vapor or gas in the air by volume. Below the LEL or LFL, the air/contaminant mixture is theoretically too “lean” to burn (see also upper explosive limit).

m3

Cubic meter. A volume measurement in the metric system. One m3 is about 45.3 cubic feet, or 1.3 cubic yards.

Mechanical exhaust

A powered device, e.g., a motor-driven fan, that removes contaminants from a work area or enclosure

Melting point

The temperature at which a solid changes to a liquid. A melting range may be given for mixtures.

mg/kg

Milligrams per kilogram. A term used in experimental testing to indicate the dose of a test substance, in milligrams, that was given for each kilogram of body weight of the test animal.

mg/m3

Milligrams per cubic meter. A way of expressing the concentration of dusts, gases, aerosols, or mists in the air.

Milligram (mg)

A unit of weight in the metric system. One thousand milligrams equals one gram.

Milliliter (ml)

A metric unit used to measure capacity. One milliliter equals one cubic centimeter. One thousand milliliters equals one liter.

Mist

A suspension in air of finely divided particles of liquid

Mucous membrane

A protective lining of cells found, for example, in the mouth, throat, nose, and other parts of the respiratory system

Mutagen

A substance capable of causing damage to genes and chromosomes, particularly those of sperm or egg cells, resulting in mutations

Mutation

A genetic alteration that can be inherited, thus affecting future generations

Narcosis

A state of deep unconsciousness caused by the influence of a drug or other chemical

National Toxicology Program

( NTP )

Publishes the biennial Report on Carcinogens, listing substances either known or anticipated to be carcinogens

National Fire Protection Association (NFPA)

Provides information on fire protection and prevention. The NFPA 704 Standard System for the Identification of the Hazards of Materials for Emergency Response describes a hazard-warning labeling system that rates the hazard of a material during a fire. The hazards are divided into health, flammability, and reactivity categories and appear in a well-known diamond system using numerals from 0 through 4 to indicate severity of the hazard. Zero indicates no special hazard and 4 indicates severe hazard.

NFPA 45 Standard on Fire Protection in Laboratories Using Chemicals provides basic requirements to protect life and property through prevention and control of fires and explosions involving the use of chemicals in laboratory-scale operations.

Nephrotoxin

A chemical that causes kidney damage (e.g., uranium)

Neurotoxin

A chemical whose primary toxic effect is on the nervous system (e.g., carbon disulfide)

Odor threshold

The lowest concentration of a substance's vapor, in air, that a person can detect by smell. Odor thresholds are highly variable, depending on the individual and the nature of the substance.

Olfactory

Refers to the sense of smell

Oral

Refers to the mouth and route of exposure by ingestion

Organic peroxide

An organic compound that contains the bivalent -O-O- structure and that may be considered a structural derivative of hydrogen peroxide, where one or both of the hydrogen atoms has been replaced by an organic radical

Occupational Safety and Health Administration (OSHA)

The federal agency that develops and enforces occupational safety and health standards for most industry and business in the United States. OSHA may approve state plans that meet or exceed the stringency of the federal standards, such as Cal/OSHA, the California occupational safety and health standards adopted by the Lab.

Oxidation

A reaction in which a substance combines with oxygen to cause chemical change (e.g., fire). In a broader sense, oxidation is a reaction in which electrons are lost and is accompanied by reduction — a reaction in which electrons are gained.

Oxidizer

A material that causes the ignition of combustible materials without an external source of ignition. When mixed with combustible materials, an oxidizer increases the rate of burning of these materials when the mixtures are ignited. Oxidizers can evolve oxygen, and can therefore support combustion in an oxygen-free atmosphere. They are usually unstable or reactive.

Oxygen deficiency

An atmosphere having less than the normal percentage of oxygen found in normal air. Normal air contains 21% oxygen at sea level.

Permissible exposure limit (PEL)

An exposure limit that is published and enforced by Cal/OSHA as a legal standard. PEL may be either a time-weighted-average (TWA) exposure limit (8-hour), a 15-minute TWA short-term exposure limit (STEL), or a ceiling (C). The PELs are found in Table AC-1 of Cal/OSHA regulation CCR 5155, Airborne Contaminants. (See also TLV). “Skin” notation: This designation sometimes appears alongside a TLV or PEL. It refers to the possibility of absorption of the particular chemical through the skin and eyes. Thus, protection of large surface areas of skin should be considered to prevent skin absorption so that the TLV is not invalidated.

Personal protective equipment (PPE)

Any devices or clothing worn by the worker to protect against hazards in the environment. Examples are respirators, gloves, and chemical splash goggles.

pH

A measure of how acidic or basic (caustic) a substance is on a scale of 1 (very acidic) to 14 (very basic); pH 7 indicates that the substance is neutral

Physical hazard

A physical hazard is a chemical posing one of the following hazardous effects: explosive; flammable (gases, aerosols, liquids, or solids); oxidizer (liquid, solid or gas); self-reactive; pyrophoric (liquid or solid); self-heating; organic peroxide; corrosive to metal; gas under pressure; or in contact with water emits flammable gas.

Polymerization

A chemical reaction in which individual molecules combine to form a single large molecule (a polymer). Hazardous polymerization is an uncontrolled reaction releasing large amounts of energy (heat).

ppb (parts per billion)

A measurement used to express very small concentrations of a given substance present in a mixture. Often used as a unit to measure the parts (by volume) of a gas or vapor in a billion parts of air.

ppm (parts per million)

A measurement used to express very small concentrations of a given substance present in a mixture. Often used as a unit to measure the parts (by volume) of a gas or vapor in a million parts of air.

psi (pounds per square inch)

A unit of pressure measurement used with compressed gases, etc.

Pulmonary

Refers to the lungs.

Pyrophoric

A chemical that can ignite spontaneously in air at or below 130°F

Reactivity

A substance’s susceptibility to undergoing a chemical reaction or change that may result in dangerous side effects, such as explosions, burning, and corrosive or toxic emissions. The conditions that cause the reaction, such as heat, other chemicals, and being dropped, will usually be specified as “Conditions to Avoid” when a chemical’s reactivity is discussed on an SDS.

Reproductive toxins

Chemicals that affect reproductive capabilities, including chromosomal damage (mutations) and effects on fetuses (teratogenesis)

Respirator

A device designed to protect the wearer from inhaling harmful contaminants

Respiratory hazard

An airborne contaminant that, when it enters the body via inhalation, has an adverse health effect

Respiratory protective equipment

Air-cleaning or air-supply respirators that protect against toxic materials in the air

Route of entry

The means by which a toxic substance enters the body. For example, absorption through the skin, inhalation, ingestion. May also be called mode of entry.

Safety Data Sheet (SDS)

A Safety Data Sheet (formerly Material Safety Data Sheets) is a manufacturer/importer's informational document produced for a chemical that describes its hazards, chemical and physical properties, and recommended precautions for handling and storage  

Safety line managers/management

Supervisors, managers, and work leads are part of the safety line management chain from each worker to the Laboratory Director. Supervisors and managers are part of the formal management chain, and they have the responsibility for adhering to all EHS policies and safe work practices. Work leads (who may be non-management) derive authority from formal laboratory managers and/or supervisors to ensure that day-to-day work, operations, and activities in their assigned area(s) and activities are conducted safely and within established work authorizations. Supervisors, managers and work leads are collectively referred to as “safety line managers.”

Secondary container

A container into which personnel transfer material from the vendor- supplied container

Select carcinogen

Any substance that meets one of the following criteria:

• It is regulated by Cal/OSHA as a carcinogen
• It is listed under the category, “known to be carcinogens,” in the biennial Report on Carcinogens published by the National Toxicology Program (NTP) (latest edition)
• It is listed under Group 1 (“carcinogenic to humans”) in the monographs published by the International Agency for Research on Cancer (IARC) (latest editions)
• It is listed in either Group 2A or 2B by IARC or under the category, “reasonably anticipated to be carcinogens” by NTP, and causes statistically significant tumor incidence in experimental animals in accordance with any of the following criteria:

• After inhalation exposure of 6-7 hours per day, 5 days per week, for a significant portion of a lifetime to dosages of less than 10 mg/m3;
• After repeated skin application of less than 300 mg/kg of body weight per week; or
• After oral dosages of less than 50 mg/kg of body weight per day.

Sensitizer

A chemical that causes a substantial proportion of exposed people or animals to develop an allergic reaction in normal tissue after a single or repeated exposure. Once an individual is sensitized, a future exposure to the agent in lower amounts than the original exposure will result in an allergic response.

Short-term exposure limit (STEL)

Represented as STEL or TLV-STEL, the maximum concentration to which workers can be exposed for a short period of time (15 minutes) for only four times throughout the day with at least one hour between exposures. The daily TLV-TWA must not be exceeded.

Solubility in water

Indicates the amount, in %, of a substance that will dissolve in water. Solubility information is important for determining spill-cleanup and fire fighting procedures.

Solvent

A liquid that dissolves other substances. Some common solvents are water, alcohol, and mineral spirits.

Suspect carcinogen

A substance that might cause cancer in humans but has not yet been proven to do so

Synonym

Another name by which a chemical is known. For example, synonyms for methyl alcohol are methanol and wood alcohol.

Systemic

Spread throughout the body; affecting many or all body systems or organs; not localized in one spot or area

Systemic poison

A substance that has a toxic effect upon several organ systems of the body

Target organ effects

Effects on specific organs of the body caused by exposure to a hazardous chemical

Teratogen

An agent or substance that may cause physical defects in the developing embryo or fetus when a pregnant female is exposed to that substance

Technical area

Generally include laboratories, shops, workrooms, and similar areas. Offices, conference rooms, food preparation and consumption areas such as the cafeteria, kitchenettes, and break rooms are generally not Technical Areas.

Threshold limit value (TLV)

Airborne concentrations of substances devised by the ACGIH that represent conditions under which it is believed that nearly all workers may be exposed day after day with no adverse effect. TLVs are advisory exposure guidelines, not legal standards, that are based on evidence from industrial experience, animal studies, or human studies, when they exist. There are three types of TLVs:

• Time-weighted average (TLV-TWA)
• Short-term exposure limit (TLV-STEL)
• Ceiling (TLV-C)

(See also PEL.) “SKIN” notation: This designation sometimes appears alongside a TLV or PEL. It refers to the possibility of absorption of the particular chemical through the skin and eyes. Thus, protection of large surface areas of skin should be considered to prevent skin absorption so that the TLV is not invalidated.

Threshold limit value-ceiling (TLV-C)

The maximum concentration of a toxic substance for which exposure is allowed. This limit is not to be exceeded, even momentarily. The TWA must still be observed.

Time-weighted average (TWA)

The exposure limit averaged over a normal 8-hour workday or 40-hour workweek

Toxic substance

A substance that causes harmful biological effects after either short-term or long-term exposure. See “highly toxic” in this glossary.

Toxicity

A relative measure of the adverse biological effects that can result from exposure to a harmful substance. See “highly toxic” in this glossary.

Trade name

The commercial name or trademark by which a chemical is known. One chemical may have a variety of trade names, depending on the manufacturers or distributors involved.

Unstable (reactive)

A chemical if it vigorously polymerizes, decomposes, condenses, or undergoes other undesirable chemical changes during normal handling or storage

Upper explosive limit (UEL)
or
Upper flammable limit (UFL)

The concentration of a substance above which an ignition source (flame, spark, etc.) will not create a flame or explosion. Above this level, the air/contaminant mixture is too “rich” to burn (see also LEL/LFL).

Vapor

The gas given off by a liquid or solid at room temperature

Ventilation

Circulation and exchange of air and the method by which this is accomplished

Vertigo

A state of dizziness, and possibly disorientation

Viscosity

A term used to describe the rate at which a liquid flows or pours. A very viscous liquid, like molasses, flows slowly.

Volatile

A term used for a liquid that evaporates at room temperature. Very volatile liquids, such as gasoline, form vapors (evaporate) quickly and are a breathing hazard.

Water-reactive

Term applied to a chemical that reacts with water to release a flammable or toxic gas

Work leads

Employees (who may be non management) who derive authority from formal Laboratory managers and/or supervisors to ensure that day-to-day work, operations, and activities in their assigned area(s) and activities are conducted safely and within established work authorizations