As of February 28th, 2023, NLM will discontinue the Wireless Information System for Emergency Responders (WISER), the website (https://wiser.nlm.nih.gov) and WebWISER (https://webwiser.nlm.nih.gov), and the standalone applications for Windows PCs, iOS app, and Android app.
Other sources of Hazmat or Chemical, Biological, Radiological, Nuclear (CBRN) information are available with the following resources:
This WISER content is available in multiple languages.
Density / Specific Gravity
0.7134 at 20 deg C/4 deg C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001. 677.