law: Factories Act, 1948 
  15. Artificial humidification 
  (1) In respect of all factories in which the humidity of the air
  
  is artificially increased, the State Government may make rules,- 
  (a) prescribing standards of humidification;
  (b) regulating the methods used for
  
  artificially increasing the humidity of the air;
  (c) directing prescribed tests for determining
  
  the humidity of the air to be correctly carried out and recorded;
  (d) prescribing methods to be adopted for
  
  securing adequate ventilation and cooling of the air in the workrooms.
  (2) In any factory in which the humidity of the air is
  
  artificially increased, the water used for the purpose shall be taken from a
  
  public supply, or other source of drinking water, or shall be effectively
  
  purified before it is so used.
  (3) If it appears to an Inspector that the water used in a
  
  factory for increasing humidity which is required to be effectively purified
  
  under sub-section (2) is not effectively purified he may serve on the manager
  
  of the factory an order in writing, specifying the measures which in his
  
  opinion would be adopted, and requiring them to be carried out before specified
  
  date.