Curbing Respirable Crystalline Silica: What to Expect

On June 23, 2016, OSHA issued the final rule to limit worker exposure to respirable crystalline silica in order to reduce ill health occurrences such as lung cancer and chronic obstructive pulmonary disease. Respirable crystalline silica can be generated through a range of everyday work activities, including sawing brick or concrete.

There will be two standards, one for construction and one for general industry and maritime, each with different compliance schedules. With enforcement for the construction standard beginning Sept. 23, 2017, it’s important to understand how to be prepared.

The new standard has reduced the permissible exposure limit (PEL) for construction and general industry to a limit of 50 μg/m3 averaged over an eight-hour workday, similar to the limits already set in European countries. The Congressional Research Service predicts the new exposure level, and further actions employers must take, will prevent 642 employee deaths per year.

Additional requirements of the standard include:  
  • limiting worker access to areas where they may be exposed to respirable crystalline silica; 
  • offering medical exams every three years where exposure may reach or exceed 25 μg/m3 over an eight-hour average for 30 or more days in a year, and for construction workers required to wear respirators for 30 or more days in a year;
  • training workers to limit exposure to respirable crystalline silica; and
  • maintaining records of workers’ exposure to respirable crystalline silica.
Compliance Methods
Groups representing employers, laborers and manufacturers have resisted the standard, citing OSHA’s predications as unfeasible and inaccurate. Individuals have even questioned the link to worker exposure to crystalline silica and subsequent medical conditions.

In a bid to ensure the transition process runs as smoothly as possible, and to take individual employer requirements into account, OSHA has provided three different ways employers can comply with the standard. Employers can choose from one of the three methods or any combination of methods to ensure their workforce is appropriately protected. Construction industry employers are exempt from the PEL and exposure monitoring requirements if they comply with the engineering controls and work practices specified in the new standards.
  1. Table method: A table has been created that lists the different tasks and equipment control methods OSHA has determined will reduce the exposure to the acceptable level, factoring in different times and environments. If employers provide the right task controls and equipment, there is no additional need for air monitoring. 
  2. Performance or objective data: With this method, employers are permitted to use objective data to provide evidence that the control methods in place reduce the exposure limit to below the PEL. This could be air monitoring compiled by the employer or a third party that sufficiently indicates the exposure level.
  3. Scheduled air monitoring program: In this instance, exposure can be assessed through a dedicated air monitoring program, and the employer generates its own data to prove adherence to the standard limits. Employers are required to implement such a program when worker exposure exceeds 25 μg/m3 during an eight-hour control period. 
To comply with the standard, the following schedule must be adhered to.
  • If initial results indicate exposures are below the action level (25 μg/m3), no additional monitoring is necessary.
  • If the monitoring results indicate exposures are above the action level, but below the PEL, additional monitoring would be required within six months.
  • If the exposure monitoring indicates exposures above the PEL, additional monitoring must be repeated within three months.
  • If subsequent monitoring (not the initial monitoring) indicates exposures are below the action level, the employer must repeat the monitoring until two consecutive measurements (taken seven or more days apart) are below the action level. At that point, the employer can discontinue monitoring.
This option gives employers the chance to generate their own exposure data with complete understanding of how and where employers are exposed. 

How to Monitor Dust
Monitoring solutions for this include personal dust sampling pumps to monitor individual exposure and real-time dust monitors that assess the occupational risks by a walkthrough survey that checks existing controls. For the case of crystalline silica, personal sampling is required, which will ultimately give the correct assessment of silica exposure.

The first action needed is a proper risk assessment to answer some key questions:
  • Who is exposed and to what?
  • For how long are they exposed?
  • How much are they exposed to? 
Monitoring must be done in a way that does not impact workers’ comfort or productivity. 

With the progress in data capture and reporting technology, solutions are available that enable full remote monitoring. For example, the individual conducting the monitoring does not need to physically check the product itself; rather, it is accessed via Bluetooth. Irrespective of whether it is monitoring in a confined space, an abnormal working environment or required over a long period of time or distance, the worker does not need to be disturbed and exposure to dust can be monitored.

 
Tim Turney is technical product manager at Casella. For more information, visit casellasolutions.com.