States and territories, with the exclusion of VIC and WA, are now covered under the WHS Act. While the legislation is essentially the same (other than VIC and WA), the Commonwealth, states and territories all have their own respective sets of WHS laws and regulations. These laws are administered and regulated by separate regulatory authorities.
DHA is classified as a Commonwealth Government Business Enterprise, and as such is covered under Commonwealth WHS Laws. DHA contractors are covered by the relevant WHS laws of the state or territory in which the business is operating, and as such are regulated by the WHS regulator of that state or territory.
For further information, including an example, please refer to our page entitled Regulatory framework.