KERAMIDA and FS&D, two of the most respected names in the foundry industry, have partnered to provide the full range of services to assist our clients in compliance with the new OSHA Silica Regulations.

Our Respirable Silica Reduction Program includes:

  • Assembling and Documenting the Exposure Control Plan

  • Exposure Studies and Mapping of Respirable Silica by location in Plant Air

  • Foundry Audit: Evaluation of Existing Processes and Practices to Determine Source and Work Practice Reduction Opportunities

  • Reassess Respirable Silica Exposure Levels

  • Investigate and Recommend Ventilation / Air Pollution Control Improvements

  • Assistance with Process Control Improvement Implementation and Related Services

Read below to learn more about OSHA's Silica Rule and how KERAMIDA can help, or contact us today to speak to one of our experienced Industrial Hygienists.

OSHA's Silica Rule and Silica Exposure

In 2018, the Occupational Safety and Health Administration (OSHA) launched enforcement for their newly developed rule regulating exposure of respirable crystalline silica to general industry employees. The most important development in the new standard is the significantly reduced permissible exposure limit (PEL) for respirable crystalline silica. The new PEL is set at 50 micrograms per cubic meter of air. One million micrograms is the same as one gram. For illustration purposes, one standard sugar packet is typically filled with one gram of sugar. To put it in context, if you distribute that one packet of sugar in enough air to make a concentration of sugar that is the same as the PEL for silica, you will cover an area the size of a football field, 13 feet high.


The problem with respirable silica is that it is so small. The definition of a respirable particle is one that can reach the lower lung tissue without getting caught in the mucous membranes higher in your respiratory system. The size of a respirable silica particle must be smaller than 10 micrometers in aerodynamic diameter to penetrate this far. Aerodynamic diameter is the equivalent diameter of a round particle that settles out of air at the same velocity as irregular-shaped silica particles.

If you take a ball point pen and make the smallest single dot you can see, it will likely be just a bit larger than 200 micrometers. The diameter of a respirable silica particle is smaller than 10 micrometers!

The smallness of the particle is directly proportional to the rate at which it settles out of air. The larger the particle, the faster it will settle out. According to the World Health Organization, a 1 micrometer silica particle falls through air at about 0.03 mm per second. At that rate it would take 169 minutes for the particle to fall 1 foot. With any kind of air movement at all, these airborne particles can travel great distances before settling out.

What does all this mean for general industry management trying to get a handle on silica sources, exposure values, and controls? 

The OSHA PEL only defines exposure parameters based on personal samples, those samples worn on the body of an employee during a shift. Taking these samples is an effective way to assess personal exposure for a given task on a given shift; however, they do not yield any specific information regarding the process origin of the particles they collect.

Consider a manufacturing facility where the floor plan is such that each room is 75% segregated, with one out of four walls open to the rest of the facility. This is a typical configuration for many facilities that have isolated, yet related, manufacturing processes as the products are worked through the build logic. A sample taken on an employee in one room will capture his or her exposure over the course of that shift; this includes any departures from that room for breaks, trips to the bathroom, restocking of materials, meal times, etc. If a source of silica in another room (even one across the facility) releases respirable particles several feet above the floor, then with a standard HVAC system, the particles will likely reach the employee at their breathing zone long before they would settle out. 

Silica Compliance Challenges


In the real world it’s not so clean, and we cannot just assume that particles settle out of air at the rate they do in perfect laboratory settings. In each facility there are turbulence factors, multiple sources of air movement, and thermal effects, just to name a few. These particles could essentially end up anywhere, dependent on the complex nature of the building. To determine the final location of particle distribution would be practically impossible for most facilities, given the myriad of competing forces present. 

Many employers make the mistake of assuming that employee exposures to respirable dust are primarily associated with the tasks of the sampled employee. At times this may be true, but as you can see, this method of defining point sources and areas is not likely to be accurate enough to reduce airborne particulate to a noticeable degree for the sampled employee. One of the first problems employers meet is the fact that they do not fully know where the particles are originating or, worse yet, where they are congregating.

Silica Solutions & Guidance

Silica Mapping

KERAMIDA has developed its own one-of-a-kind methodology for overcoming these obstacles and defining the presence, quantity, and spatial location of respirable silica in nearly any type of facility. Our industrial hygiene professionals work to determine the nature of silica distribution with enough accuracy and resolution to develop a visual map of the concentration of silica in your specific facility. These maps have helped over 50 clients determine appropriate policies and controls for reduction of airborne silica loading. Among those helped most significantly by the KERAMIDA Particle Map are metal casters (Iron and non-ferrous foundries), masonry product manufactures, and construction entities, among others.

The concentration of airborne respirable silica is recorded by location at hundreds of defined points. A high-resolution map image is then generated to represent relative silica loading in plant air.

What is the turn-around time?

KERAMIDA typically only needs one production day to complete the on-site work, two days for some larger or more complex facilities. The remaining laboratory work, mathematic calculations, contour image creation, and development of applicable initial recommendations are performed off-site in order to efficiently deliver the final information to the client in the shortest amount of time.

KERAMIDA's goal is to provide clients with the tools they need for accurate handling of all regulatory obligations. For silica compliance, this service is no exception. However, should you request assistance with application of the mapping information to your specific facility and equipment, KERAMIDA offers consulting services by providing on-site professionals to analyze processes, tasks, equipment, air movement, and other pertinent factors for the targeted reduction of airborne silica. 

OSHA has made it clear that employers must perform all feasible actions to control silica exposure in the workplace. This feasibility can be defined as financial or technological. Note that financial feasibility is not a simple cost-benefit analysis. The position that has been held by regulators on this matter has been far more aggressive. However, employers contemplating expensive engineering controls which put the company in jeopardy while providing very little reduction in silica exposure, may not be in the best interest of that employer. KERAMIDA recommends performing the necessary research and testing to determine technological feasibility in terms of what works, not in terms of dollars spent.

Cost-Effective Silica Compliance Strategies

Over the years, KERAMIDA has seen many instances of the expensive shotgun approach to engineering controls, where facility managers, through the best of intentions, apply broad strokes of conventional controls without taking the necessary first step of identifying sources and distribution. On many occasions, a significant reduction in the number and cost of these controls could have been achieved had they been focused directly on the problem. In some cases, engineering controls have even increased exposure for employees in the immediate or adjacent areas.

KERAMIDA has also worked with employers who had previously made attempts to perform area sampling where the hired firm simply collected samples in the areas with the highest expected exposure. This approach does very little to advance the facility’s understanding of exposure distribution. Instead, the employer is only informed of what he already knows; that the exposure in those areas is relatively high. The KERAMIDA particle map is designed to give new information, an accurate depiction of the critical conditions that cannot be simply observed with the naked eye.

Armed with real-world information about silica distribution, KERAMIDA's clients can skip the guessing and implement focused, efficient control of respirable crystalline silica... Then, the next time you perform personal employee sampling, it won’t be a guessing game, and your results will represent the effects of targeted control.

If KERAMIDA’s unique silica mapping process could help your facility, call us at 1-800-508-8034 for more information or contact us here. Our experienced Industrial Hygienists are prepared to answer any of your questions.

Silica Related Blog Posts:

Silica Related News Posts:

Related Services: