Section 24-708. Exemptions.

The  following  persons, facilities and hazardous
  substances shall be exempt from the requirements of section  24-706  and
  24-711:  (a)  facilities where the only hazardous substances, except for
  those substances on the special health hazard list pursuant  to  section
  24-704,  were  present during the preceding calendar year in mixtures in
  which the total content of the hazardous substance was of one percent or
  less by weight or volume per container unless such  hazardous  substance
  was  present  at  the  facility  in  an aggregate amount of five hundred
  pounds or more; (b) owners or  tenants  of  residential  buildings  that
  contain  no commercial or manufacturing enterprise; or (c) fossil fuels,
  petroleum products, and combustible or flammable chemicals or materials,
  the manufacture, transportation, or storage of which is subject  to  the
  jurisdiction  of  the  fire department pursuant to title twenty-seven of
  the code.