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OSHA glossary
The terms safety teams look up, one page each. Every page opens with a plain-English definition, then quotes its source word for word, shows the standards that use the term and links the terms around it.
The quotations are copied from the eCFR as of October 27, 2026, from the U.S. Code (2024 edition) and, for TRIR and the DART rate, from the Bureau of Labor Statistics. A test compares each quotation with a stored copy of its source, and a separate script compares that copy with the live sources. Where the law has no definition of a term, the page says so.
- Terms
- 44
- By
- Cairn
- Updated
- October 29, 2026
- Legal text
- eCFR, October 27, 2026
A
- Abatement
- Action by an employer to comply with a cited standard or regulation or to eliminate a recognized hazard OSHA identified.
- Anchorage
- In construction, a secure point of attachment for lifelines, lanyards or deceleration devices.
- Authorized employee
- A person who locks out or tags out machines or equipment to perform servicing or maintenance on them.
B
- Bloodborne pathogens
- Pathogenic microorganisms present in human blood that can cause disease in humans, including HBV and HIV.
C
- Cave-in
- The separation of soil or rock from the side of an excavation, or from under a shield or support system, and its sudden movement in, enough to entrap, bury or otherwise injure and immobilize a person.
- Competent person
- In construction, someone who can identify existing and predictable hazards and has authorization to take prompt corrective measures.
- Confined space
- A space large enough to enter and work in, with limited or restricted means of entry or exit, not designed for continuous occupancy.
D
- DART rate
- Days away, restricted or transferred rate: cases with days away, restricted work or job transfer per 100 full-time workers.
- Days away from work
- Calendar days an employee is unable to work, or a health care professional recommends staying out, because of a work-related injury or illness, counted from the day after it began.
- De minimis violation
- A violation with no direct or immediate relationship to safety or health, for which OSHA may issue a notice instead of a citation.
E
- Employer
- A person engaged in a business affecting commerce who has employees. The federal government and state and local governments are excluded.
- Energy isolating device
- A mechanical device that physically prevents the transmission or release of energy, such as a circuit breaker, disconnect switch or line valve.
- Establishment
- A single physical location where business is conducted or where services or industrial operations are performed.
F
- Failure to abate
- Failing to correct a cited violation within the period permitted, which can be penalized for each day it continues.
- First aid
- A complete list of simple treatments. The list includes bandages, wound cleaning and nonprescription medication at nonprescription strength.
- Fit test
- The use of a protocol to qualitatively or quantitatively evaluate the fit of a respirator on an individual.
G
- General Duty Clause
- Section 5(a)(1) of the OSH Act, requiring employment free from recognized hazards that are likely to cause death or serious physical harm.
- Guardrail system
- In construction, a barrier erected to prevent employees from falling to lower levels.
H
- Hazardous chemical
- Any chemical classified as a physical hazard or health hazard, a simple asphyxiant, combustible dust or a hazard not otherwise classified.
I
- IDLH
- In the respiratory protection standard, an atmosphere that poses an immediate threat to life, would cause irreversible harm or would impair escape.
- Imminent danger
- Conditions that could reasonably be expected to cause death or serious physical harm immediately or before ordinary enforcement can remove them.
L
- Leading edge
- In construction fall protection, the edge of a floor, roof or formwork that changes location as more sections are placed, formed or constructed.
- Lockout/tagout
- Placing a lockout device or a tagout device on an energy isolating device so that equipment is not operated during servicing.
M
- Medical treatment
- The management and care of a patient to combat disease or disorder. It does not include first aid, observation or diagnostic procedures.
N
- Notice of contest
- An employer's written notice that it will contest a citation or proposed penalty, postmarked within 15 working days.
O
- Occupational exposure
- Reasonably anticipated skin, eye, mucous membrane or parenteral contact with blood or other potentially infectious materials from an employee's duties.
- OSHA 300 Log
- The Log of Work-Related Injuries and Illnesses, where employers enter each recordable case.
- OSHA 300A summary
- The annual summary of the injuries and illnesses on the OSHA 300 Log, certified and posted by February 1 and kept up until April 30.
- OSHA citation
- The written notice OSHA issues when it believes an employer has violated the OSH Act, a standard or a regulation.
- Other-than-serious violation
- A violation of the OSH Act, a standard or a regulation that is specifically determined not to be of a serious nature.
P
- Permit-required confined space
- A confined space with a hazardous atmosphere, an engulfment hazard, a trapping configuration or any other recognized serious hazard.
- Personal fall arrest system
- In construction, a system used to arrest an employee in a fall from a working level, made of an anchorage, connectors and a body belt or harness.
- Protective system
- A method of protecting employees from cave-ins, falling or rolling material, or the collapse of adjacent structures.
Q
- Qualified person
- In construction, someone with a recognized degree, certificate or professional standing, or extensive knowledge, training and experience, who has shown an ability to solve problems on the work.
R
- Recordable injury
- A new, work-related case that results in death, days away, restricted work, job transfer, treatment beyond first aid, loss of consciousness or a significant diagnosis, or fits a special case in 1904.8 to 1904.11.
- Restricted work or job transfer
- When a work-related injury or illness keeps an employee from routine job functions or the full workday, or moves them to another job part of the day.
S
- Safety data sheet
- Written or printed material about a hazardous chemical, prepared under paragraph (g) of the Hazard Communication standard.
- Scaffold
- Any temporary elevated platform, supported or suspended, and its supporting structure, used to support employees or materials.
- Serious violation
- A violation with a substantial probability that death or serious physical harm could result, unless the employer could not have known of it.
- Severe injury reporting
- Report a work-related death within 8 hours and an in-patient hospitalization, amputation or loss of an eye within 24 hours, with time limits and exceptions.
T
- Trench
- A narrow excavation made below the surface of the ground, generally deeper than wide and no more than 15 feet wide at the bottom, including one narrowed to that by forms or structures.
- TRIR
- Total recordable incident rate: recordable cases per 100 full-time workers, calculated as cases times 200,000 divided by hours worked.
W
- Willful and repeat violations
- The violation categories with the highest civil penalty limit, for employers who willfully or repeatedly violate the OSH Act.
- Work-related injury or illness
- An injury or illness caused or contributed to by an event or exposure in the work environment, or significantly aggravated by one.