If your workers wear respiratory protective equipment (RPE) against respirable crystalline silica in Queensland, one number comes up again and again: 30 days. It is worth being precise about what that number is, and, just as importantly, what it is not.
Where the duty comes from
Respirable crystalline silica (RCS) is a Schedule 14 hazardous chemical under the Work Health and Safety Regulation 2011 (Qld), Part 7.1. Where there is a significant risk to health from exposure to a Schedule 14 chemical, the person conducting a business or undertaking (PCBU) must provide health monitoring for the worker. The Managing respirable crystalline silica dust Code of Practice 2022 (Qld) sets out how that plays out for silica work: the silica control plan, air monitoring, and health monitoring for high-risk crystalline silica work.
So the health-monitoring duty is statutory. What the regulation does not do is hand you a single, universal “wear RPE for N days and monitoring is triggered” number. That is a decision for your risk assessment.
What the 30-day threshold actually is
The 30-day figure is a tenant-tunable default: a sensible, common starting point that reflects sustained exposure, not a statutory trigger. In Obliwise, the rule reads:
When a worker records 30 distinct RPE usage-days on a respirable-hazard task, raise a health-monitoring obligation (registered medical practitioner, baseline plus periodic) and an RPE fit-test renewal.
Three things make this defensible rather than arbitrary:
- It counts distinct usage-days, not shifts or hours. A worker who dons RPE against a respirable hazard on 30 separate days has a materially different exposure profile from someone who wore it twice.
- It cites its ground. The rule carries the WHS Regulation 2011 (Qld) Part 7.1 citation, so anyone reviewing it can see exactly why it exists.
- You set the number. Thirty is the default; your risk assessment might land on fewer days for a high-silica task, or a different trigger entirely. The point is that the threshold is yours, recorded and versioned.
Why “you own the number” matters
Under Queensland WHS law you are the duty-holder. A platform that silently decided your health-monitoring triggers for you would be making a legal determination on your behalf, exactly the wrong posture for a compliance tool.
Obliwise takes the opposite stance. Every obligation rule installs disabled. You opt each one in, tune its threshold to your own reading of the current regulation and your risk assessment, and the system records that decision. When the obligation fires, it is advisory: it flags what your own configured rule says the law requires next, and it records the citation, the parameters, and the time. If Workplace Health and Safety Queensland, or your board, later asks “why did you schedule that health monitoring, and when did you know?”, the answer is a point-in-time record, not a memory.
What fires alongside it
The 30-day rule does not act alone. A silica programme in Queensland typically runs several rules together:
- Exposure-standard exceedance: a hygiene measurement above the RCS workplace exposure standard (0.05 mg/m³, 8-hour TWA) raises spirometry-based health monitoring for the exposed group.
- Control plan + air monitoring: creating a chemical exposure assessment for an RCS product raises the silica control plan and enrols the site in air monitoring.
- Fit-test renewal: an approaching RPE fit-test date (AS/NZS 1715:2009) raises a renewal obligation before it lapses.
Each is a small, cited, versioned rule. Together they are the difference between storing your silica records and knowing what they oblige you to do next.
The short version
The 30-day RPE threshold in Queensland is a well-grounded default, not a statutory magic number. The statutory part is the health-monitoring duty under WHS Regulation 2011 (Qld) Part 7.1; the 30 days is how you choose to operationalise it. Obliwise makes that choice explicit, cited, and auditable, and then does the watching for you.