Section 28. Limitation of right to compensation

The  right  to claim
  compensation under this chapter shall be barred, except  as  hereinafter
  provided,  unless  within  two  years  after  the  accident, or if death
  results therefrom within  two  years  after  such  death,  a  claim  for
  compensation  shall  be  filed  with  the chairman, but the employer and
  insurance carrier shall be deemed to have waived the bar of the  statute
  unless  the  objection to the failure to file the claim within two years
  is raised on the first hearing on such claim at  which  all  parties  in
  interest  are  present.  The  right of an employee to claim compensation
  under this chapter for disablement caused by  any  occupational  disease
  including  but  not  limited  to compressed air illness or its sequelae,
  silicosis or other dust disease, latent or  delayed  pathological  bone,
  blood or lung changes or malignancies due to occupational exposure to or
  contact  with  arsenic,  benzol,  beryllium, zirconium, cadmium, chrome,
  lead or fluorine or to exposure to x-rays, radium,  ionizing  radiation,
  radio-active  substances,  or  any  other chemical compound shall not be
  barred by the failure of the employee to file a claim within such period
  of two years, provided such claim shall be filed after  such  period  of
  two  years and within two years after disablement and after the claimant
  knew or should have known that the disease is or was due to  the  nature
  of  the  employment.  No  case in which an advance payment is made to an
  employee or to his dependents in case of death shall be  barred  by  the
  failure of the employee or his dependents to file a claim, and the board
  may  at  any time order a hearing on any such case in the same manner as
  though a claim for compensation had been filed.