Caution and Warning Signs

Signs are printed out and updated by personnel using the Caution Sign page in MyChem. It is the responsibility of personnel (responsible party, supervisor, manager, etc.) to update the signs if significant changes occur in chemical inventories, entry requirements, hazardous materials authorizations or contacts.

• Occupants replace signs as needed by updating their MyChem inventory and using the Caution Signs page available in the MyChem menu to print a new sign.
• You must have an account in the MyChem chemical inventory system to create or edit a sign based on the chemical inventory in your laboratory, shop or maker space.
• After logging into MyChem, click on the Caution Sign menu item and select the building and room (or suite) to create a customized sign for your location.

Use the Caution Signs Instructions to create and post your Caution sign, including:

• There are two kinds of Caution signs – Room Signs and Suite Signs.
• For areas or rooms with multiple entrances – caution signs must be posted at each entrance and show the same information.
• Look for rooms within a room or rooms accessible only from another room. A collection of rooms like this is considered to be a suite and needs a Suite Sign posted at each main/primary entrance, with Room Signs posted at the entrances of the inner rooms.
• Within a suite, only rooms that have a door and are used as lab spaces need a Room Sign.
• Any rooms which are not used for chemical or wet lab work but are still lab spaces (procedure room, microscope room, autoclave room, etc.) should have a Caution sign, even if the chemical diamond shows only zeros and no PPE is required.
• Alcove spaces, open benches, and corridors within a suite that are identified with a room number do not get their own Room Sign. Their inventories are combined into and reflected on the Suite Sign for the suite they are part of via the Caution Sign Tool.
• All labs that have spaces/alcoves/corridors/inner rooms which are part of a suite must identify each space/alcove/corridor/inner room by room number on the Suite Sign for that suite.
• Suites within a suite will not be listed on the same Caution signs.

Note: All chemicals, compressed gases, and compressed air tanks should be listed in MyChem under the room number that corresponds with their exact location, regardless if that room has its own Caution sign. This applies to chemicals and compressed gas tanks located in rooms without doors, alcoves, open benches, and corridors.

An example map of Caution sign locations is shown in the Caution Sign Instructions.

In addition to the chemical hazards listed under the NFPA diamond, hazards identified on Caution signs with pictograms include:

• Biohazards
• Compressed gases
• Cryogens
• Lead
• Radioactive materials

Research and teaching laboratories with biohazards are required to post a biohazard warning sign that restricts laboratory access during work with biohazards, communicates the agents in use, and specifies entry and exit requirements.

Visit the Biological Research Safety webpage for more information.

The American National Standard for Safe Use of Lasers (ANSI Z136.1) requires that lasers and laser systems have appropriate warning labels and that the rooms/laboratory in which they operate bear appropriate hazard signs to warn others of the potential hazard. Laser hazard signs must be conspicuously posted at all entrance(s) and, if deemed necessary by the laser safety officer, should also be posted within the laser-controlled area.

The word "Danger” or “Warning” must be used with all signs and labels associated with all lasers and laser systems that exceeded the MPE for irradiance, including all Class 3B and Class 4 lasers or laser systems. The laser-specific (type), Optical Density (OD) of the protective eyewear and wavelength shall be shown on the sign for a location requiring the use of eyewear.

The word “Notice” must be used on signs posted outside temporary laser-controlled area when service or maintenance is in-process.

Laser hazard warning, danger, or notice signs and labels (except lighted hazards warning signs) are provided by the laser safety officer and are available from EH&S Radiation Safety Office.

Due to the large liquid to gas expansion that takes place upon evaporation, liquid nitrogen (LN2) is capable of displacing sufficient oxygen to create an oxygen-deficient environment in a small or insufficiently ventilated space, leading to the risk of asphyxiation. 
Working in or entering an oxygen deficient atmosphere may cause unconsciousness without warning, potentially leading to asphyxiation and death. To avoid such conditions, liquid nitrogen should only be stored, handled and used in well ventilated areas with oxygen alarms and signage warning of the asphyxiation hazard.

University personnel are required to complete training covering the hazards of working with LN2 prior to beginning work.

Appropriate radiation warning signs or labels must be used to designate radiation areas and to identify radioactive material containers or rooms containing radioactive materials. During the setup of a new laboratory, Radiation Safety staff post or provide appropriate signage, but the PI is responsible for maintaining that posting. Requirements for the types and locations of these signs or labels are provided in the UW Radiation Safety Manual.

Appropriate radiation warning sign and labels must be posted on the X-ray source housing, near a switch that energizes the X-ray, and on entrances to lab/room containing open beam x-ray source. During setup of the radiation-producing machine, RS will post and provide appropriate signage for the lab/room/equipment.

"CAUTION: X-ray" signs are provided by EH&S Radiation Safety Office.

The regulatory requirements listed below are addressed by the caution sign.

• Seattle Fire Code (PDF) Items 5 and 7 require NFPA diamond and compressed gas label
• State Department of Health (WAC 246-221-120) requires radiation symbol
• CDC/NIH Biosafety in Microbiological and Biomedical Laboratories (PDF) BMBL guidance requires posting of a biohazard sign (Section IV.A.9), personal protection requirements (Section IV. A.9 - Biosafety Level 2 and above), and general occupational health requirements (Section IV A. 3)
• Washington State Bloodborne Pathogens rule requires biohazard sign on containers
• NIH Guidelines for Recombinant DNA require biohazard sign, Appendix G-II-C-2-e
• Food or drink is prohibited in laboratories/shops by federal and state regulations and UW policy:
  

  • Labor and Industries Rule WAC 296-823-14035

  • Department of Health Radioactive Materials Rules WAC 246-235-130

  • UW Laboratory Safety Manual, Section 2 A.4

• UW Biosafety Manual Section IV B.2 (PDF)
• NIH Guidelines for Recombinant DNA, Appendix G-II-A-1-e
• WAC-296-800-140 Create an Accident Prevention Program