Section 27-415. Laboratories

All laboratories required to register under the
  requirements  of  the  New  York  city health code shall comply with the
  following:
    (a) Construction. All buildings in which such laboratories occur shall
  be of noncombustible group I construction.
    (b)  Floors.  All  floors  shall  comply  with   the   fire-resistance
  requirements  for  the  class of construction, and provide the degree of
  radioactive resistance required by applicable city, state,  and  federal
  regulations.   A  finished  material  shall  be  applied  to  provide  a
  continuous nonporous surface which may be readily removed.
    (c) Interior finish.  All  insulation  of  acoustical  treatments  and
  interior  partitions  shall  be  of  noncombustible  material. Walls and
  ceilings shall have nonporous finishes of class A rating.
    (d) Sprinkler protection.  Automatic  sprinkler  protection  complying
  with the construction provisions of subchapter seventeen of this chapter
  shall be provided, and such protection shall be designed for the type of
  combustible  materials  wherever  such  material  is  used,  and for the
  radioactive material that may be expected to melt, vaporize, or  oxidize
  under  fire  conditions. Laboratory equipment susceptible to damage from
  water or other materials used in the sprinkler system may be shielded by
  hoods except when the equipment provides a source of  combustion.  Where
  sprinkler  protection uses water, or small water-spray installations are
  used to fight small  isolated  fires,  floors  shall  be  provided  with
  drainage  so  that  water  may  be  carried to retention tanks for later
  disposal as required by the New York city health code when contamination
  of the water is to be anticipated.
    (e) Electrical controls. Electrical controls and  equipment  shall  be
  installed  in accordance with the requirements of the electrical code of
  the city of New York.
    (f) Ventilation. Exhaust air from areas in which radioactive materials
  are used or stored shall be exhausted to the outdoors in such manner  as
  not  to  create  a health hazard, and shall not be recirculated to other
  areas of the building.  Air  pressure  in  rooms  in  which  radioactive
  materials  are  used  or  stored  shall  be maintained below the the air
  pressure of adjoining rooms, so that there is  no  flow  of  radioactive
  gases or dusts into adjoining rooms.
    (1)   Ducts  shall  be  of  sheet  steel  of  not  less  than  No.  16
  manufacturers' standard gauge  or  of  other  equivalent  noncombustible
  material   having   a  melting  point  above  eighteen  hundred  degrees
  Fahrenheit. Exhaust ducts within the building, on the discharge side  of
  the fan, shall be welded airtight. Exhaust ducts within the building, on
  the suction side of the fan shall have laps in the direction of air flow
  with  smoke-tight  joints,  and  shall  be  subjected to a smoke test in
  accordance with the requirements for chimneys in subchapter  fifteen  of
  this chapter. Access hatches with tight-closing covers shall be provided
  for cleaning and for fire-fighting in the exhaust system ducts.
    (2)  Fume  hoods shall be exhausted to the outdoors. Controls for hood
  fans shall be interlocked so that contaminated air cannot be drawn  into
  any space from a hood where the exhaust fan is not in operation.
    (3)  Fan  equipment other than the impeller and impeller housing shall
  be located outside the exhaust stream.
    (4) When the degree of contamination of the exhaust stream exceeds the
  concentration limits permitted by the health code, the duct system shall
  be equipped with devices to decontaminate the air to a safe level before
  discharging to the outdoor air.
    (g) Plumbing. Drainage lines from sinks used  for  radioactive  wastes
  shall  be without traps, and shall lead to retention tanks when required
  by the provisions of the New York city health code.