The Occupational Health and Safety Administration (OSHA) outlines essential steps employers must take to prevent workplace accidents and protect workers from hazards—these requirements include installing mandatory safety signs. The administration’s main regulation governing safety signage is OSHA section 1910.145, which requires that employers provide warnings about “hazardous or potentially hazardous conditions, equipment or operations which are out of the ordinary, unexpected or not readily apparent.” One of the most common ways to alert employees is by implementing relevant OSHA-compliant safety signage throughout the facility.

What Safety Signs Are Required By OSHA? 

According to OSHA signage standards, there are 5 major classifications of accident prevention messaging required in the workplace: Danger, Warning, Caution, Safety Instruction, and Biological Hazard. Choose the appropriate level of messaging and adhere to the following language and color specifications to create OSHA-approved signs for improved safety in the workplace.

Type of sign

What it is used for

Other information


Indicates immediate hazards that require special precautions and that, if not avoided, may result in death or serious injury Danger signs should be predominantly red, with a black outline and a white lower panel for additional text. 

Employers must instruct workers that Danger signs mean special precautions must be taken.


A hazard level between “Caution” and “Danger” Warning signs have no set color requirements, but orange is recommended, with contrasting lettering and symbols.

This is an optional category. Employers may choose to use Danger and Caution signs with no intermediate category. A Warning sign is insufficient if a Danger sign is needed.


Warns against potential hazards that may result in minor or moderate injury; or cautions against unsafe practices Caution signs must be primarily yellow with a black upper panel and borders, yellow “caution” lettering, and empty lower portion for additional messaging.

Employers must instruct workers that a Caution sign means proper precautions are required.

Safety Instruction

Communicates general instructions or suggestions relative to safety measures Safety instruction signs should be white with a green upper panel and white lettering for the primary message. Remaining wording should be black on white.

Biological Hazard

Signifies the actual or potential presence of a biohazard—infectious agents presenting a risk of death, injury, or illness Must include the signal word “Biological Hazard” or “BIOHAZARD,” or the biological hazard symbol.

Biohazard signs are often fluorescent orange or orange-red, with symbols and text in contrasting color.

Other OSHA Signage Requirements

Of course, the above list of mandatory OSHA safety signs is not exhaustive. Scattered throughout OSHA regulations are additional standards stipulating that employers who engage in certain types of industrial processes or who work with certain types of materials post safety signs. Consider these examples for other safety signs that are required in the workplace, according to OSHA.

OSHA Exit Sign Requirements

Under OSHA regulations, each means of egress must be marked with an “Exit” sign. Signs may also be needed to show the direction of travel to the nearest exit. In addition, doorways or passages along an emergency evacuation route that could be mistaken for an exit must be clearly and accordingly marked with a “Not an Exit” sign, or with messaging that identifies where the door leads, such as “closet.”

Exit and Not An Exit Safety Signs

OSHA requires “Exit” signs on exits and “Not an Exit” signs on doors that could be mistaken as an exit

OSHA Construction Signage Requirements

Construction and manufacturing environments often present specific hazards that may require additional signage, according to OSHA. These include signs for trip and fall prevention, notice of electrical hazards, and machine safety messaging.

Fire Safety Signs

In addition to properly marked exits and exit routes, OSHA signage standards set specific requirements around fire safety, including clearly marking the location of fire extinguishers and fire-fighting equipment, ensuring these locations are kept clear for access, and properly labeling areas that could become hazardous or dangerous in the event of a fire.

Does OSHA Set “No Smoking” Sign Requirements?

Yes. Many OSHA sign regulations require conspicuous  “No Smoking” signage when combustible or flammable materials are present. Appropriate signs are also required in order to implement a smoke-free workplace policy; OSHA stipulates that “no smoking” signage should be placed at all entrances and exits of the building in which the practice is prohibited.

No Smoking Safety Signs

“No Smoking” signs may be required by OSHA

Optional OSHA Safety Signs for the Workplace

Consider the following instances where signs, although not required, can increase safety and supplement strategies for OSHA compliance: 

  • Use signs to indicate the location of first aid kits for easier identification from a distance.
  • PPE (Personal Protective Equipment) signage can remind staff to wear safety goggles, earplugs, or non-slip shoes in certain areas of your facility.
  • Implement industrial floor tape or directional signage to designate proper traffic flow and separate pedestrian traffic from forklifts or other vehicles. 

Do States Have Their Own Signage Requirements?

In less than half of states, the OSHA program is administered by the state itself rather than the federal government. Some of these states have tacked additional safety sign requirements onto the national standards. To determine whether your state is one of them, refer to the Directory of States with OSHA-Approved Occupational Safety and Health Plans (external link).

Workplace safety is mandated by OSHA, and OSHA-required signage plays an important role in preventing accidents and keeping workers safe while on the job. For more tips on using floor tape and signage to promote safety in industrial facilities and the workplace, explore our Resource Center.

Disclaimer: Although every effort has been made to provide accurate information, InSite Solutions expressly disclaims all warranties and liability of any type whatsoever relating to the use of this document. Any questions about signage requirements may be directed to OSHA.