BIS  Marking on Raw Rubber
  Bureau of Indian Standards (BIS) and the Rubber Board jointly  operate a scheme for testing and inspection of rubber. Block Rubber (ISNR) and  Centrifuged Latex are graded by physical and chemical tests to ensure conformity  to set standards.  The conformity is  authenticated by ISI marking on the product lots.  The specification prescribed are :
                                  ISNR   : IS  4588-1986
                                  Centrifuged  Latex: IS 5430-1981
                                  Double  Centrifuged Latex: IS 11001-1984
                                  Periodic  inspection of processing centres are carried out to ensure quality of  processing.