What type of air monitoring can be used for silica?
Occupational hygienists recommend the type of air monitoring depending on the workplace, dust exposures and the purpose of the assessment. There are three main types of air monitoring used for silica dust exposure assessments.
1. Personal Exposure Monitoring
Personal exposure monitoring is used to determine workers’ baseline exposure to respirable crystalline silica while carrying out work activities. Workers wear a personal dust monitor fitted to them which collects the air sample from the worker’s breathing zone. The sample is then sent to the laboratory and analysed for respirable crystalline silica. The results of laboratory analysis are then compared with workplace exposure standards. Personal exposure assessments are also required for compliance purposes and to check if further controls are required.
2. Positional / Static Air Monitoring
Positional or static air monitoring is used to measure the airborne concentration of dust and respirable crystalline silica in the work areas. Static air monitoring can identify the areas with high dust concentration and the information can be used to implement further controls. Static dust monitoring is also used for verifying the effectiveness of controls in the work area. As static dust monitoring provides a concentration in the work area and not personal exposure, the results cannot be compared with workplace exposure standards for compliance purposes.
3. Realtime Air Monitoring
Realtime monitoring is used to identify the work processes that generate high levels of dust, it is an effective tool to check the effectiveness of controls in real-time. Real-time monitoring can identify the work processes that expose workers to high concentrations of dust and the information can be used to implement and verify the effectiveness of controls. The results of real-time air monitoring cannot be compared to the workplace exposure standard for compliance purposes. Real-time air monitoring is often carried out as a part of an initial walk-through survey to identify exposures and processes that create dust exposures. Real-time monitoring can identify workers that are at risk of silica dust exposure and then personal exposure monitoring for workers can be carried out to determine their exposures.
