SCAQMD Rule 1466 Compliance: Dust Control Measures & Particulate Monitoring in the Workplace

Dust is a reality of everyday life, but many industries, including construction, agriculture, mining, waste and recycling, masonry, and manufacturing, produce high levels of dust and require workplaces to implement proven dust control measures to ensure the health and safety of employees.

What Is Silica Dust? What Is Fugitive Dust?

Dust is a particulate matter (PM) consisting of small particles—so miniscule that they can become airborne during activities involving certain materials.

Silica is found in a wide range of materials in the earth's crust, including soil, sand, granite and other minerals, slate, sandstone, and artificial stone. During work activities, if these materials are cut, chipped, ground, or otherwise disturbed, it can cause small particles of silica to become airborne. The resulting silica dust is often respirable, which means the particles are small enough that they can be inhaled and cause damage to the lungs.

Fugitive dust is a term used to describe PM that remains suspended in the air. When soil is disturbed by mechanical activities or the wind, a significant amount of atmospheric dust is discharged into the atmosphere. This fugitive dust "escapes" into the atmosphere instead of being exhausted through a confined flow stream (such as a chimney or exhaust pipe), giving the name its origin.

The Importance of Control Measures for Dust in the Workplace

Over time, excessive inhalation of silica or fugitive dust poses a serious health risk to workers and can lead to long-term illness or injury. When this dust is inhaled, the tiny particles can travel into the lungs, causing scarring, inflammation, respiratory illness, lung damage, and even premature death. Exposure to silica dust can also increase the risk of bacterial infection.

To mitigate the effects of dust exposure, many states and industries have established dust control measures and emissions standards. A leader in these efforts is the South Coast Air Quality Management District (SCAQMD).

SCAQMD Rule 1466

In 2018, SCAQMD adopted Rule 1466: Control of Particulate Emissions from Soils with Toxic Air Contaminants. The purpose of Rule 1466 is to minimize off-site fugitive dust emissions caused by earth-moving activities at sites containing certain toxic air contaminants by establishing air monitoring and dust control measures.

Under Rule 1466, applicable operations in areas of California regulated by SCAQMD must install SCAQMD-approved signage on the property line, notify SCAQMD as required when dust emissions exceed standards, follow various dust control measures, and install a minimum of two direct-reading, real-time particulate monitors on-site—at least one at an upwind location and at least one at a downwind location.

Rule 1466 specifically regulates concentrations of particulate matter 10 micrometers (PM10) or less in diameter. If the PM10 site contribution exceeds an average of 25 micrograms per cubic meter (µg/m3) over an hour, then operations must halt until additional dust control measures are implemented. When the PM10 concentration drops below an average of 25 µg/m3 over 30 minutes, earth-moving operations can commence.

While SCAQMD Rule 1466 only applies to parts of California, many industries and agencies across the nation look to the rule as a guide for dust control and monitoring standards in the workplace.

Workplace Dust Control Measures

Various other dust control measures in the workplace include the following:

• Use wet methods to apply water and suppress dust over large areas
• Provide well-sealed, well-ventilated, and heated/air-conditioned cabs for operators to stay free of dust
• Incorporate local exhaust ventilation in dusty work areas
• Isolate work processes with enclosures when possible
• Wear respiratory protection or personal protective equipment (PPE) when enclosed cab or wet control methods are not available
• Install dust and particulate monitors to measure fugitive dust emissions
• Replace water and air filters per manufacturer's instructions or as needed

These dust control measures are essential to ensure worker safety and maintain compliance with regulations, especially when working with silica materials.

Industry-Leading Dust & Particulate Monitoring Equipment

To maintain a safe workplace and ensure you are in compliance with SCAQMD Rule 1466 or other relevant regulations, it's important to accurately monitor the amount and size of fine particulates, including dust, suspended in the air. At RAECO Rents, we offer a selection of dust and particulate monitoring equipment designed to measure workers' exposure to respirable particles. Choose from indoor monitors, outdoor kits, and combination models to find a dust and particulate monitor that meets the needs of your workplace.

TSI DustTrak DRX Aerosol Particulate Monitors

The TSI DustTrak DRX 8534 Handheld Particulate Monitor and TSI DustTrak 8533 Desktop Particulate Monitor are high-quality devices that monitor for the mass concentration of aerosols and total PM size. These battery-operated, light-scattering laser photometers provide real-time aerosol mass concentration readings of dust, fumes, mists, and smoke and also display total PM size, making them essential tools for monitoring dust in the workplace.