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What is ISO 23875 (RS 20 in QLD) and How to Comply?

Mining is a dirty game; even routine activities can generate airborne particles that are hazardous to human health. The new ISO 23875 regulatory requirements for HME, prioritise operator safety by limiting operator exposure and reducing machine maintenance cost and downtime.

ISO 23875 is the new international standard of air quality control systems that unifies the design, testing, operation, and maintenance of heavy machinery cabs. The regulations increase machine users safety, improve productivity, promote operator alertness, and enable companies to reach exposure reduction goals.

They focus on increasing clean air intake, allowing operators to breathe easy with the added benefit of reducing machine heating, ventilation, and air conditioning (HVAC) maintenance costs, increasing machine performance, and reducing downtime.

Benefits of Implementing ISO 23875

  • Reduced exposure to respirable particulate
  • Reduced exposure to CO2
  • Improved operator safety, comfort, and moral–supporting exposure reduction goals, health and safety efforts, and recruitment/retention
  • Improved machine uptime and lower operating costs through meeting defined maintenance intervals


The new ISO 23875 standards are an improvement on past standards, as they are considerate of the life cycle of a machine; from cabin air control systems at the time of design to the equipment arrival onsite and throughout its operating life. This holistic approach, details specific engineering and ongoing testing practice to ensure compliance.

ISO 23875 Requirements

  1. Defined CO2 Levels
    First alarm threshold: Ambient CO2 level plus 400 parts per million (PPM).
    Second CO2 alarm threshold: 2,500 PPM.
  2. Defined Fresh & Recirculation System Efficiency
    Maximum respirable particulate matter concentration less than 25 micrograms per cubic metre of air at start and end of decay test (maximum 120 second decay time).
  3. Increased Filter Efficiency Requirements
    Updated in June 2022: Filtration that exceeds 94% efficiency at 0.3 microns is recommended. Filters must pass the required intake air leakage and particle decay tests.
  4. Defined Pressurisation Requirements
    Operator enclosures must maintain a minimum pressure of 20 Pa with key on and HVAC blower turned off.
  5. Defined, Real-Time Monitoring Requirements
    Monitor must include an audible alarm for CO2 and pressurisation to alert the operator when levels exceed the permissible pressure and CO2 thresholds.


This considered approach can be contributed (in part) to the diverse working group that ISO assembled to assess air quality system requirements in the mining industry. Sy-Klone International executive vice president Jeff Moredock, was recruited for the working group following his involvement in the International Society of Environmental Enclosure Engineers (ISEEE), a nonprofit concerned with preserving lives by fighting the battle against lower lung disease.

“It was exciting to see the global body of knowledge around operator enclosure engineering and performance testing come together in such a powerful way,” Moredock said.

“The working group brought in stakeholders from over 10 countries to ensure we captured feedback and created a standard with global buy-in to guide the design and testing of air quality control systems.”

Sy-Klone International are industry leaders in air filtration solutions and have been working with heavy equipment OEMs and global distributors in the field for over 30 years. Their advanced air filtration products protect machines and their operators around the globe.

In line with the new ISO 23875 filter efficiency requirements, Sy-Klone International manufacture high-efficiency, low-restriction efficient particulate air (EPA) filters that are 99 per cent efficient at 0.3 microns.

They also offer the only integrated cabin air quality and monitoring products that meet both the air quality and monitoring engineering requirements outlined in ISO 23875.

The Sy-Klone RESPA fresh and recirculated cab air quality systemsRadialSHIELD® high-efficiency HEPA and EPA filters, and the RESPA Advisor®+ CO2 Monitor, combined with a well-sealed cab, provide the engineering controls needed to prepare a cab to meet ISO 23875 performance requirements.

NB Industries are proud to partner with Sy-Klone International as an authorised Australian distributor for their innovative products.

To learn how you can meet ISO 23875 requirements on new and existing equipment contact NB Industries today.