Wear a mask sign (M016)
A blue circle with a white head wearing a plain mask over the nose and mouth means a mask must be worn where the sign is posted. It is sign M016 in ISO 7010.
Easily confused with
How to read it
ISO 7010 registers M016 as “Wear a mask”, one of ISO 3864-1’s mandatory action signs, beside M017 for respiratory protection. The University of Houston’s lab door signs have a surgical mask pictogram, and its safety office explains that surgical masks are not personal protective equipment as such: they are on the signs because they may be an entry requirement, and they are designed to protect others in the area from the wearer’s contamination, not to protect the wearer except incidentally.
Also searched as: face mask sign, M016, mask symbol, surgical mask symbol, wear a mask symbol.
These explain what each sign means and which standard sets it. What to do in a laboratory is set by the lab’s own rules, signs and trained staff; for a chemical, refer to its label and safety data sheet.
Mask or respirator
The two signs ask for different things. M017 calls for a respirator, which the CDC describes as covering the nose and mouth or the whole face and filtering out infectious or harmful particles. M016 calls for a mask. Houston’s description puts the difference in who is protected: the respirator protects the wearer, the surgical mask protects the room.
Read next
- Next in Lab safety symbolsEyewash station sign (E011)A green square with a white face and a jet of water rising to the eye marks the location of an emergency eyewash. It is sign E011 in ISO 7010.
- The same shape in African flagsFlag of EthiopiaEthiopia’s flag is green, yellow and red in equal horizontal stripes with a blue disc in the centre holding a yellow star of equal lines with yellow rays. Ethiopia’s Flag Proclamation makes the green labour, fertility and development, the yellow hope, justice and equality, and the red sacrifice and heroism for freedom and equality; the blue disc is peace and the star the unity of Ethiopia’s nations, nationalities and peoples.
More lab safety symbols
The same shape elsewhere
Browse symbols drawn with circles or lines.
Sources
- ISO 3864-1:2011, Graphical symbols — Safety colours and safety signs — Part 1: Design principles for safety signs and safety markings (preview), ISO 3864-1:2011, International Organization for Standardization, preview via iTeh Standards, 3.5, Table 1, 6.3
- ISO 7010:2011, Graphical symbols — Safety colours and safety signs — Registered safety signs (preview), ISO 7010:2011, International Organization for Standardization, preview via iTeh Standards, Table 1
- Laboratory Doorsigns, University of Houston Environmental Health and Safety, Personal Protective Equipment
- Recognizing the Biosafety Levels (Quick Learn), U.S. Centers for Disease Control and Prevention, Glossary: Respirator
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research
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