[cryptonector]

There's not as much difference as you say. The NJ page says

> New Jersey law (N.J.S.A. 34:5-182) requires that employers provide workers with full-face air-purifying respirators when engineering controls cannot be used. Use of respirators should be part of a complete respiratory protection program.

While the CA page says

  Respirators should only be used:
   • As a last resort for
    protection when local
    exhaust ventilation or
    water controls are not
    feasible or do not
    adequately control
    employee airborne
    exposures.
  • Where exposures
    exceed the permissible
    exposure limit (50 μg/m3,
    8-hour TWA) while installing or implementing feasible
    engineering and work practice controls.
  • When the employee is in a regulated area.

I.e., both say that other measures must be applied first.