Section 278. Limitation of number of occupants

The number of persons who
  may be employed in a  factory  building  or  portion  thereof  shall  be
  limited  to  such  number  as can safely escape from the building by the
  exits provided in the building and shall not exceed the following:
    1. In a building erected after October  first,  nineteen  hundred  and
  thirteen,  fourteen persons for every full twenty-two inches in width of
  stairway provided for such floor and conforming to the requirements  for
  required  exits, except as to extension to the roof.  No allowance shall
  be made for any excess in width of less than twenty-two inches.
    2. In a  building  erected  before  October  first,  nineteen  hundred
  thirteen,  fourteen  persons  for  every  eighteen  inches  in  width of
  stairway provided for such floor and conforming to the requirements  for
  required  exits  except  as  to extension to the roof. For any excess in
  width of less than eighteen inches,  a  proportionate  increase  in  the
  number  of  occupants  shall  be  allowed.  If  a stairway has winders a
  deduction of ten per centum shall be made in computing the  capacity  of
  such stairway.
    3.  On  any floor which is more than ten feet from the one immediately
  beneath, the number "fourteen" allowed in subdivisions one and  two  may
  be  increased  respectively  by one person for every sixteen inches over
  ten feet between the two floors provided such stairways conform  to  the
  requirements for required exits except as to extension to the roof.
    4.  In  addition to the number of persons allowed in subdivisions one,
  two and three, so many persons may be  employed  on  any  floor  as  can
  occupy  the stair halls, allowing five square feet of unobstructed floor
  space per person where the stairways and stair  halls  are  enclosed  by
  partitions  as  required  by  sections  two  hundred and seventy and two
  hundred and seventy-one.
    5. The number of persons permitted to be employed on any  floor  under
  subdivisions  one,  two, three and four may be increased one hundred per
  centum where there is maintained throughout the  building  an  automatic
  sprinkler  system  conforming to the requirements of section two hundred
  eighty and to  the  rules  of  the  board  and  where,  if  required  by
  subdivisions  one  and  two  of section two hundred seventy-nine, a fire
  alarm signal system is maintained and fire drills are conducted.
    6. On any floor at which a horizontal exit is provided so many persons
  may be employed as can occupy the smaller of the spaces on  either  side
  of the fireproof partitions or fire walls, or as can occupy the floor of
  an  adjacent  building which is connected with such floor by openings in
  the wall or walls between the buildings  or  by  exterior  balconies  or
  bridges  in  addition  to  the occupants of such connected floor in such
  adjacent building, allowing five square feet of unobstructed floor space
  per person. Openings constituting required exit  doorways,  or  if  such
  exits are balconies or bridges, the openings leading thereto shall be of
  sufficient aggregate width to allow eighteen inches in width of openings
  for each fifty persons or fraction thereof employed on such floor in the
  case of factory buildings erected before October first, nineteen hundred
  and  thirteen,  and  twenty-two  inches in the case of factory buildings
  erected after that date.
    7. Where a floor is occupied by more than one tenant,  the  commission
  may prescribe how many of the persons allowed to occupy such floor under
  the provisions of this section may occupy the space of each tenant.
    8. In every factory building the commissioner shall cause to be posted
  in  a  conspicuous  place  in  every  stairhall  and  workroom,  notices
  specifying the number of persons that may occupy each floor  thereof  in
  accordance with the provisions of this section. If any floor is occupied
  by  more  than  one  tenant,  such  notices shall be posted in the space

  occupied by each tenant, and shall state the number of persons that  may
  occupy such space. Every such notice shall bear the date when posted.