The model WHS Regulations have duties that apply to working outside. This includes managing environmental risks and the provision of adequate facilities for workers.
PCBU’s must, so far as is reasonably practicable:
ensure the health and safety of workers and others at your workplace
consult with workers who carry out work for the business or undertaking and who are (or are likely to be) directly affected by a health and safety matter, and
consult cooperate and coordinate activities with all other relevant duty holders.
Workers and other people at the workplace also have duties, including taking reasonable care for their own health and safety.
A person can have more than one duty and more than one person can have the same duty at the same time