A <a href="https://en.wikipedia.org/wiki/United_States_Department_of_Defense" class="extiw" title="w:United States Department of Defense">United States Department of Defense</a> chemical hazard symbol for "Highly Toxic Chemical Hazard - Wear full protective clothing, Set 1", identifiable by the red color of the figure and ring.<br>Set 1 PPE consists of <a href="https://en.wikipedia.org/wiki/Self-contained_breathing_apparatus" class="extiw" title="w:Self-contained breathing apparatus">Self-contained breathing apparatus (SCBA)</a>, and chemical protective clothing.
<a href="//commons.wikimedia.org/wiki/User:The_Navigators" title="User:The Navigators">The Navigators</a>
<a rel="nofollow" class="external text" href="https://www.wbdg.org/FFC/DOD/DODMAN/605509-M-V1.pdf">DoDM 6055.09-M-V1, February 29, 2008</a> Page 54.