Definitions, Acronyms, Idioms, Jargon

Many of these are included in hopes that non-native English speakers will find hem helpful. Many others are included because they are somewhat specific to the fields of occupational safety and industrial hygiene.

Terms	Description
8h-TWA	Eight hour time weighted average. Example: person is exposed to airborne hexane at 300 ppm for 2 hours, 200 ppm for 2 hours, 100 ppm for 1 hour, and nothing further for the other 3 hours of their 8 hour work shift. The 8h-TWA in this case is
ablation	wearing away (also grinding away). Refers to the action of laser beam on parts of the eye. (Also used to refer to the erosive process which reduces the size of glaciers.)
ACGIH	American College of Government Industrial Hygienists. Publishes Threshold Limit Value occupational exposure guidelines and BEIs (biological exposure indices) which are used as maximal exposure criteria for many substances.
acute	intense, short duration, one time occurrence. Used as in acute exposure, acute effects, acute toxicity.
acute hazardous waste	term used by EPA regulations to refer to 239 listed substances and 6 source-characterized classes (for example "Wastes (except wastewater and spent carbon from hydrogen chloride purification) from the production or manufacturing use (as a reactant, chemical intermediate, or component in a formulating process) of tri- or tetrachlorophenol, or of intermediates used to produce their pesticide derivatives. (This listing does not include wastes from the production of Hexachlorophene from highly purified 2,4,5- trichlorophenol.)")
aka	"also known as"
article	as used in Hazard Communication Standard 29 CFR 1910.1200 article is defined as " a manufactured item other than a fluid or particle: (1) which is formed to a specific shape or design during manufacture; (ii) which has end use function(s) dependent in whole or in part upon its shape or design during end use; and (iii) which under normal conditions of use does not release more than very small quantities, e.g., minute or trace amounts of a hazardous chemical (as determined under paragraph (d) of this section), and does not pose a physical hazard or health risk to employees." Contact Dr. Lila Albin at REM IH section, 40204, for help with interpretation.
ASAP	As Soon As Possible.
ASTM	Originally American Society for Testing and Materials, formed in 1898, now known as ASTM International it is a voluntary standards development organization which has created thousands of standard test methods by which materials and produced items are tested and evaluated and compared.
biological safety	This term usually applies to considerations pertaining to exposure to disease-causing organisms (capable of causing disease in humans, other animals, plants, and/or other life forms), as well as the associated waste disposal concerns.
CHP	Chemical Hygiene Plan. Required (by OSHA Laboratory Standard) for "empoyers engaged in laboratory use of hazardous chemicals." For years it was a 5" x 8.5" yellow book printed by REM. Not anymore. Electronic, paper copies by request or print your own.
chronic	lengthy, ongoing, repeated low level occurence. Used as in chronic exposure, chronic effects, chronic toxicity.
DEXA	Dual Energy X-ray Absorptiometry. A bone density monitoring instrument - it has two different low energy x-rays and measures the differences in absorption by the bone to look at bone density and a measure of osteoporosis.
DOL	United States Department of Labor. DOL web site.
employer	"The employer" is named as responsible for every sort of OSHA requirement. Most company policies pertaining to satisfying these requirements (including Purdue's policies) name "the supervisor" as responsible for training, oversight, safe conditions, proper PPE, and basically ensuring that the safety and health of the staff are protected.
engineering controls	Control measures designed into a system, which are rather more exempt from human error than administrative controls (rules). For example, general room ventilation is an engineering control which protects people from inhalation exposures. Two-handed controls on a punch press constitutes an engineering control designed to prevent the operator's hand from being IN the press on activation....
ergonomic(s)	Ergonomics is best defined as the relationships between a person's body and his/her work activities. Repetitive stress injuries such as carpal tunnel syndrome, and certain neck, back, and leg disorders due to poor fit of office furniture are among the most common worker health problems falling into the ergonomics category.
flash point	defined as the temperature at which an ignition source 1 cm from the surface of the liquid will cause ignition. The standard method is defined by ASTM and most flash points are measured in a "closed cup" flashpoint tester. Discrepancies/disagreements are found in the literature for some substances, but the values are usually fairly close.
health physics	aka radiological health, aka radiation safety. Health physics is the study of the principles and procedures of providing protection for individuals, the population, and the environment from the harmful effects of ionizing and nonionizing radiation.
HEPA	A "High Efficiency Particulate Air" filter will remove 97% of particulate matter of size 0.3 microns. That's the test a filter must pass to be a HEPA filter. This size (0.3 microns) is the bottom of a U-shaped efficiency curve, and the filtering of particles of smaller and larger sizes is generally better than 97% (there's a limit on the small size, don't know what). See old reference G. Briggs Phillips and Robert S. Runkle, CRC Press, Biomedical Applications of Laminar Airflow, 1973.
IDLH	Immediately Dangerous to Life or Health. Table of values at NIOSH.
IFF	Math jargon for "IF AND ONLY IF." Commonly mistaken for a typographical error.
IH Industrial Hygiene	From ABIH (American Board of Industrial Hygiene) strategic Plan 1999-2000: "Industrial hygiene" is the science and practice devoted to the anticipation, recognition, evaluation and control of those environmental factors and stresses arising in or from the workplace that may cause sickness, impaired health and well-being, or significant discomfort among workers and may also impact the general community.
municipal waste	Term commonly used to describe the "regular" trash. Garbage, rubbish, cans/bottles/papers/foodstuffs. Contrast with "chemical waste," "hazardous waste," "biological waste," "biohaz waste," "medical waste," "radioactive waste...."
laboratory	(pasted from 29 CFR 1910.1450) "Laboratory" means a facility where the "laboratory use of hazardous chemicals" occurs. It is a workplace where relatively small quantities of hazardous chemicals are used on a non-production basis.
laboratory scale	(pasted from 29 CFR 1910.1450) "Laboratory scale" means work with substances in which the containers used for reactions, transfers, and other handling of substances are designed to be easily and safety manipulated by one person. "Laboratory scale" excludes those workplaces whose function is to produce commercial quantities of materials.
laboratory use	Laboratory use of hazardous chemicals is defined by OSHA in this manner: "Laboratory use of hazardous chemicals" means handling or use of such chemicals in which all of the following conditions are met: Chemical manipulations are carried out on a "laboratory scale;" Multiple chemical procedures or chemicals are used; The procedures involved are not part of a production process, nor in any way simulate a production process; and "Protective laboratory practices and equipment" are available and in common use to minimize the potential for employee exposure to hazardous chemicals.
Lab Standard	The OSHA regulation 29 CFR 1910.1450, which pertains specifically to employers engaged in laboratory use of hazardous chemicals
LEL	Lower Explosive Limit: flammable solvents are an explosion hazard when the solvent vapor concentration in air is greater than the lower explosive limit (LEL) and less than the upper explosive limit (UEL). Below the LEL, the mixture is too lean to burn. For example, the LEL of ethyl alcohol is 3.3%. Note that this is 33,000 ppm for comparison with the permissible exposure level of 1000 ppm.
local	effect of a toxin or other hazard at or close to the site of contact, as in local effects (sulfuric acid burns and tissue damage from cryogen contact are local effects)
luck out	Slang meaning to be lucky, to be fortunate.
NFPA	National Fire Protection Association
OSHA	Occupational Safety and Health Administration, an agency within the United States Department of Labor. OSHA is responsible for developing and enforcing regulations which protect worker safety and health. OSHA web site. DOL web site.
OTJ	On The Job training. Also called OJT, for On the Job Training. Very common acronym in workplaces where on-the-job training takes place.
PED	Purdue Electronic Directory. It is aka the MailHub directory.
PEL(s)	Permissible Exposure Limit(s) are part of the OSHA regulations and are enforceable by law. Usually (but not always) given as ppm, and usually (but not always) 8h-TWA.
PPE	Personal Protective Equipment - items attached to (worn on) the body to protect it, e.g. lab coat, hard hat, steel-toe boots, gloves, goggles, faceshield, apron, respirator, batting helmet, cup, oven mitt...
ppm	parts per million. In OSHA regulations the ppm is usually a volume/volume (x10⁶) expression of concentration for airborne contaminants. Example: 1 L of toluene vapor in 2000 L of contaminated air = 1/2000 x 10⁶ = 500 ppm toluene. (It works like percents only after dividing you move the decimal place 6 places instead of two!)
Protective laboratory practices and equipment	(pasted from 29 CFR 1910.1450) "Protective laboratory practices and equipment" means those laboratory procedures, practices and equipment accepted by laboratory health and safety experts as effective, or that the employer can show to be effective, in minimizing the potential for employee exposure to hazardous chemicals.
Public Health	This term usually includes considerations of purity/sanitation of drinking water, food preparation activities, municipal waste disposal, and sewage treatment, as well as protection of the general public from contagious disease
reg/regs	Regulation(s). Enforceable by law. Sometimes called "standards" but the word standard is also used more generically to include non-regulatory advice.
SOP	Standard Operating Procedure. A written protocol including safety precautions required for the work.
squat	strictly idomatic use: used to mean nothing or anything as in "I had dust in my eyes and couldn't see squat," or "My English TA knows squat about Tennyson." Euphemism (more polite substitute) for crude term meaning feces. (E.g. "My Chemistry teacher doesn't know sh*t about people.")
standard	Generically used to mean standard of comparison, an ideal state. ANSI (American National Standards Institute) is not a regulatory agency, and ANSI standards are not enforceable by law unless they have been incorporated into regulations (and some have). OSHA is a regulatory agency, and OSHA regulations are often called OSHA standards. They are indeed enforceable by law.
supervisor	The supervisor is the faculty member responsible for the research (for research staff engaged in research activities), the shop foreman (foreperson?) who signs the timecards (for hourly service staff), the manager who writes the performance appraisals (much of the A/P staff), the professor in charge of the course (for all who teach and assist in that course)... It's impossible to cover every case here; ask yourself who would be deemed "supervisor" by the OSHA investigator during an accident investigation? (The supervisor is not a postdoc or technician or any other subordinate put "in charge of safety" by a supervisor wishing to disclaim the responsibility.) The question of who supervises the faculty has never been answered or tested much.
systemic	effect of a toxin at a site well removed from the site of contact. Kidney damage from inhalation exposure to chloroform is an example.
tidy up	meaning to clean; to make neat, clean, tidy.
TLV	Threshold Limit Value. Simplified, this is a concentration of airborne gas or vapor to which the normal person can be exposed without injury for 8 hours per day, 5 days per week for an unlimited period. Not a regulatory standard, but a recommendation from ACGIH.
UEL	Upper Explosive Limit: flammable solvents are an explosion hazard when the solvent vapor concentration in air is greater than the lower explosive limit (LEL) and less than the upper explosive limit (UEL). Below the LEL, the mixture is too lean to burn. For example, the LEL of ethyl alcohol is 3.3%. Note that this is 33,000 ppm for comparison with the permissible exposure level of 1000 ppm.
VAV	Variable Air Volume. Some modern hoods possess a feedback mechanism which causes the motor or a damper to respond to changes in sash opening size. If the sash opening is increased the air volume (volume rate, actually, cubic feet per minute) is increased so as to keep the face velocity (linear feet per minute) somewhat constant.
yahoo(s)	Slightly deprecatory but humorous term used to suggest or mean ignorant people.