Our Team

Gregor Riese

Director / Principal Consultant NSW

Gregor Riese manages the NSW/ACT operations of Opira Group which is a leading provider of indoor environment risk management products and services. Opira specializes in indoor air quality, critical environments and occupational hygiene in the workplace.

Gregor has a Masters in Occupational Hygiene and Toxicology with Edith Cowan University and prior to this worked as an environmental planner/project consultant servicing the waste management and recycling industries. Gregor is an accredited WELL AP, NABERS Indoor Environment assessor and accredited for SafeTraces testing of building ventilation systems.


Establishing and operating an independent environmental and planning consultancy firm with a diverse range of projects/clientele (GCS Consulting)

Successful management of environmental and planning obligations for state owned and publicly listed waste management and recycling firms (Waste Service NSW; OneSteel Recycling)


Gregor is a regular guest speaker for industry associations across Australia and has published a number of technical papers in areas of HVAC hygiene and indoor air quality.

HVAC System Hygiene and Duct Cleaning; IHEA Journal
Operating Theatre air quality; IHEA Journal
COVID-19 and air quality in Healthcare; IHEA


Bachelor of Science | Macquaire University
Master of Occupational Hygiene and Toxicology, Safety Science | Edith Cowan University


veriDART® Certified & Recertified Professional
NABERS Accredited
WELL AP Accredited


Member (AIRAH)
Australian Institute of Refrigeration,
Air Conditioning and Heating
Member (IHEA)
Institute of Healthcare Engineering Australia
Member (ABSANZ)
Association of Biosafety for Australia and New Zealand
Member (FMA)
Facility Management Association
Member (RIA)
Restoration Industry Association
Member (IAQAA)
Indoor Air Quality Association Australia

Contact Us

1300 157 969
Brisbane Office
32 Dividend St,
Mansfield, Qld 4122
Melbourne Office
25 Graham Rd,
Clayton South, Vic 3169
Perth Office
1/194 Canning Highway,
East Fremantle WA 6158