Figure 5.
R. M. Smith’s casework sample of residues in a crack in concrete flooring from a structure fire in 1982. Reproduced from ref (102). Copyright 1982 American Chemical Society.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.