Fact Sheet Smoke Test Smoke does not enter a home unless the
plumbing is faulty. If smoke does enter a house, so can sewer
gas and other dangerous materials. Therefore, the occupant
should be notified so that repairs can be made and dangers
eliminated. Smoke does not normally enter more than one percent
of the tested homes. The current experience of the City-hired
contractor substantiates this statement. Smoke is composed of
approximately 50 percent zinc chloride and 50 percent
atmospheric moisture. The zinc chloride and moisture are
combined into a mist. The concentration of zinc chloride in a
visible cloud of smoke is a maximum 10 mg/mm3. As the cloud
becomes less visible, the concentration of zinc chloride wanes.
Zinc chloride is relatively harmless at 10 mg/m3. However, it
can be irritating, particularly to people with respiratory
ailments. Superior Signal Company has been in business since
1961 and sells over 200,000 smoke devices a year throughout the
United States.