The Cook government on Saturday announced it was expanding the number of cancers covered under presumptive legislation from 12 to 20.
The eight additional cancers covered by the laws will be thyroid, pancreatic, skin, cervical, ovarian, penile, malignant mesothelioma and lung cancer.
The changes mean current or retired career or volunteer firefighters who are diagnosed with the cancers will be presumed to have developed their disease because of their work.
While firefighters were trained and given equipment to prevent exposure to toxins, not all hazards could be eliminated, the state government said.
"The Cook government intends to include the additional eight cancers as a priority via regulations, which will ensure Western Australia is consistent with the Commonwealth," acting industrial relations minister Rita Saffioti said.
"Firefighters play such an important role in our community and the Cook government commends the thousands of Western Australians who selflessly assist in protecting our state."
The change brings WA into line with the Commonwealth, Tasmania and the ACT when it comes to presumptive cancer laws.
The United Firefighters Union of Australia welcomed the expanded laws in WA.
"Throughout the course of their careers, WA professional firefighters are routinely exposed to deadly toxins when they enter burning buildings, which are absorbed through their skin, significantly increasing their risk of developing cancer," union national secretary Greg McConville said.
The union's WA secretary Katherine O'Hara added the changes were particularly important for women as more chose to become firefighters.
"Women can now join WA's Fire and Rescue service safe in the knowledge that they'll receive the same support if they develop cancer as their male counterparts," she said.
Victorian firefighters and the state's Greens party are lobbying the government to expand its presumptive cancer laws.
The Victorian Greens on Wednesday introduced a bill to expand the scheme to include nine additional cancers, bringing the total number covered to 20.
The firefighters union called on Victoria, the Northern Territory, Queensland, NSW and South Australia to align their presumptive cancer laws with those adopted by WA.