Questions & Answers

General Information

What is silica? Silica (SiO2) comprises approximately 75% of the earth's crust. For example, beach sand is composed mainly of silica. Silica is used in a variety of applications such as glass, brick, and cement manufacturing and as a filler ingredient in dry wall compound, mortars, grouts, stucco and concrete. It's also used in many household products such as cleansers and polishes. Why does James Hardie have silica in its products? Silica is in many everyday building materials: tile, concrete, granite countertops, drywall compound, masonry bricks, pavers, etc. It is a very durable material and contributes to the stability of fiber cement. Are James Hardie products safe? Yes, James Hardie products are safe. There is no dust hazard once the product is installed on the home , or when storing and moving the product. How are fiber cement products safe if silica dust is released when cutting them? Our fiber cement products should be cut following our “Good, Better, Best” cutting guidelines, which are designed to reduce the amount of dust produced Are you changing anything with how James Hardie fiber cement products
are manufactured?
No, there’s no need to. This is about a rule change, not a concern about our products. Our fiber cement products are safe when cut according to our guidelines.
Are James Hardie fiber cement products safe to put on homes? Yes. There is no dust concern from fiber cement once it’s installed on the home. How do you now compare to other siding options? Do they have this same issue? Every type of siding, regardless of whether it’s wood, wood composite siding, bricks, stone or fiber cement, produces dust when it’s cut and is subject to a PEL standard. James Hardie leads all siding manufacturers in providing resources in the field that help enable our customers to comply with the silica PEL standard. Does the silica in James Hardie products pose a danger after the product
is installed?
No. There is no dust concern from fiber cement once it’s installed on the home.
Is it possible to exceed the current or new OSHA PEL standard when cutting or installing fiber cement? It is not possible for James Hardie to comment on every cutting situation. Exposure levels can vary based on cutting practices and tools, volume of cuts per hour, weather, location and other factors. Our recommended cutting practices are the most effective ways to control dust. In fact, using a handheld circular saw equipped with a commercially available dust collection system (our “Best” cutting practice), is deemed by OSHA to be compliant with the new, lower PEL for silica dust. For more information, refer to the OSHA Silica Rule Fact Sheet

Working with James Hardie® fiber cement products under the new OSHA Silica Rule

Is there any danger to install crews? This is about a rule change, not a concern about our products: dust generation is only an issue if our fiber cement products are not cut according to our guidelines. We are here to make it as easy as possible to enable your install crews to cut our fiber cement products properly and safely. Will I have to incur additional costs when installing JH siding to comply with the
new standard?
It depends on how you’re currently cutting our fiber cement products. We have a number of solutions today, and we are always looking for ways to enhance the usefulness and efficiency of these solutions. As part of our continual improvement culture, we evaluate new practices to help you meet the new PEL standard in a variety of production environments. . Our technical sales team will help you adapt to the new standard in the most cost-efficient way.
Is this change going to slow me down? James Hardie will provide resources that will help you select tools that allow you to cut and install our products safely and economically. Regardless of the solution you use, we are here to help ensure the impact on your crew is minimal. What changes will be expected of install crews? The tools used to install our products now can still be used under the new PEL standard. And you may already have the tools needed to comply such as HardieBlade® saw blades, shop vacuums and dust-collecting saws. Although you are responsible for safety and compliance, as part of our value-added services we can provide resources to help train your crews and provide resources help prepare your company for compliance. We’re committed to the continued, safe use of our products and your productivity. How do I become OSHA compliant so I don’t get cited for a violation? It depends on how you’re currently cutting our products and your job site. If you are unsure whether or not you are OSHA compliant, you should contact a certified industrial hygienist or other safety professional for advice. James Hardie can help you with locating these resources. If you need information about the proper way to cut our fiber cement products, you can find it here. What do you recommend is the safest method to cut your product? It depends on your specific cutting situation. James Hardie has a number of safe cutting practices that can be used to comply with both current and new PEL standard depending on your production practice. For specific guidance, you can also contact your James Hardie technical sales representative or call James Hardie Technical Services at 800-942-7343. Is it safe for me to be moving JH product around my jobsite/yard? Yes. Moving or storing fiber cement does not generate significant dust from the product. Is this change going to make James Hardie a more costly or time-intensive option? No, it will not. James Hardie is mindful of not adding additional expense or time to the installation of our siding in order to meet the new PEL standard, and our technical sales team is ready to assist with resources for tool support, training and dust control plan preparation. Is it okay to continue to stack and cut panels? Yes, as long as you follow our recommended cutting methods, which can be found here. For maximum dust control, we recommend the “Best” practice from our Good, Better, Best cutting guidelines. If you are unsure which cutting method is best suited to your job site, please contact your James Hardie installation representative to discuss your current situation.


Should I ever use a high-speed power tool (such as a circular saw) indoors? You should only use shears or a score-and-snap tool while cutting fiber cement indoors. If a power saw is needed, cut fiber cement outdoors with proper ventilation using tools selected from our "Good, Better, Best" table on this site. Where an I buy the Roan™ Dust Collecting Circular Saw? The Roan Dust Collecting Saw can be purchased anywhere James Hardie products are sold or visit to buy online. What type of blade should I use with the Roan Dust Collecting Saw? Use a HardieBlade ® saw blade when cutting fiber cement. There are many blades designed to cut fiber cement on the market.
Why is the HardieBlade™ saw blade better?
The HardieBlade™ saw blade has been designed specifically for James Hardie fiber cement products. Testing, to date, appears to suggest that a saw blade designed with fewer teeth generally creates larger dust particles (greater than 10 microns in diameter), thereby reducing the amount of smaller, respirable dust generated and reducing the risk for high exposures of respirable silica. Testing also suggests that masonry-type blades (such as continuous or segmented diamond rim blades) and abrasive blades are designed differently and create more respirable dust. As a rule of thumb, less teeth equates to lower respirable silica exposures.
Do other fiber cement blades work as well as the HardieBlade™? As well as being more effective in reducing dust, the HardieBlade saw blade has been found to cut more linear feet and maintain cut quality far longer than any other fiber cement saw blade currently on the market. Where can I find the HardieBlade™? The HardieBlade is available at dealers and lumber yards where James Hardie products are sold. The HardieBlade is also available through on-line retailers. What sizes are the blades available in?5", 7.25", 10", and 12". Is there a specific type of saw that should be used with the HardieBlade™
saw blade?
The HardieBlade is designed to be compatible with most circular, miter, and table saws. Use the most appropriate size HardieBlade for your saw. To reduce exposure to dust, the saw should be designed so that the majority of dust generated from cutting is moved away from the user. Dust-reducing saws typically have an exhaust port that can be hooked to a vacuum. A dust-reducing circular saw should be used with a dust extracting/capturing device, such as a shop vacuum with a well maintained dust filter.


What is the updated OSHA rule for silica dust and when does it take effect? The revised regulations became effective June 23, 2016. Employers were required to comply one year later, June 23, 2017, however OSHA has extended this compliance date to September 23, 2017. The revisions reduce the permissible exposure limit (PEL) for silica dust by about 80% — from 250 μg/m³ to 50 μg/m³, and affect many construction trades: concrete cutting and finishing, cutting tile, brick, stone materials and cutting fiber cement. Many construction trade groups comprised of builders, contractors and manufacturers have challenged the need and practicality of changing the silica dust regulation. As a result, the new rule is currently under judicial review, and compliance requirements or deadlines may be affected again. As an industry leader, James Hardie is prepared with tools and resources to assist our customers, regardless of how or when the new rule is implemented. Does the revised rule mean that silica-containing products like fiber cement can no longer be used?
No. The rule regulates activities that generate silica dust on a jobsite. It does not mean that silica-containing products cannot be used, or that other materials must be used instead. Many building materials including wood and paint are subject to safe use requirements, and all jobsite dust is subject to a PEL. This new OSHA rule simply focuses on silica dust.
What does this mean for installers of James Hardie fiber cement products? We will address this new PEL standard exactly like we’ve addressed other workplace safety regulations: by listening to our customers and providing them with the solutions and guidance they need to help them comply with the new standard. We have a number of solutions to help with compliance today, and we are always looking for ways to enhance the usefulness and efficiency of these solutions. We are also evaluating new practices to help you to meet the new PEL standard in a variety of production environments while continuing to provide good efficiencies. Once the standard is in effect, we will, as always, be ready with a number of flexible ways to help you meet the standard. How will James Hardie help me meet the new standard? James Hardie fiber cement products are safe to have, use and install. Silica dust is only a concern when cutting fiber cement with high speed tools such as circular saws. Storing, moving, handling and nailing fiber cement products does not present a hazard. Cutting fiber cement products using shears (mechanical, pneumatic or manual) or the score and snap method does not present a hazard.

When cutting with high speed saws, using a circular or chop saw outfitted with a HardieBlade® saw blade and a vacuum dust collection system is the most effective way to reduce dust. OSHA recognizes this and specifically states:

…for cutting fiber-cement board outdoors in accordance with Table 1 for any task duration, OSHA has determined that in such circumstances, employee exposures will be reduced to 50 μg/m³ or less when the controls specified for this task on Table 1 are fully and properly implemented. (OSHA Final Silica Rule 2016-04800)
What does the revised rule include? OSHA requires employers to take specific actions to protect workers on construction sites (OSHA Fact Sheet- OSHA’s Crystalline Silica Rule: Construction), based on the amount of silica dust they are exposed to, on average, over an 8-hour period. The table below summarizes some key points of the rule.

If silica dust exposure for a given task is…
Below action level
(AL) of 25 μg/m3
Between the AL (25 μg/m3)
and PEL (50 μg/m3)
Above the PEL (50 μg/m3)
Regulation does not
apply if exposure is
below the AL under
all foreseeable
Conduct sufficient measurements or
use objective data to show exposure
will not exceed the PEL.
• Implement engineering controls and practices to keep
exposure below the PEL
• Use respirators (e.g. NIOSH-approved dust masks) if
controls and practices are insufficient to stay below the PEL
• Offer medical exams if respirators must be worn more
than 30 days/year
• Establish and implement a written exposure plan listing tasks that expose workers to silica and
how to control exposures
• Train workers on silica exposures hazards and means to control dust
How is exposure determined? Silica exposure is determined one of two ways:

1. By referencing objective data, which means studies or reports by recognized experts who have evaluated dust exposures for certain tasks (The National Institute for Occupational Safety and Health (NIOSH) published several reports related to controlling silica dust on job sites, including concrete grinding, tuck-pointing and fiber cement.), or
2. By directly monitoring actual employee exposure

Actual exposure is measured using an air sampling device that is placed in the work area or worn by an employee. An industrial hygienist (IH) (Industrial Hygienists are degreed scientists or engineers trained to evaluate workplace health and safety issues. While there is no licensing program, the American Board of Industrial Hygiene administers a certification program; Certified Industrial Hygienists (CIH) must have be degreed, have least four years of experience and pass a 1-day exam.) will generally oversee the sample collection. The samples are collected and sent to a qualified lab for analysis and the IH will review the results and make recommendations.
What does this mean? What is “Table I?” Table I of the revised rule lists several construction site tasks that generate silica dust and specified equipment and procedures - called “engineering controls” - to keep dust below the PEL.

OSHA provides a specific Table I exemption for cutting fiber cement boards using a handheld power saw (with blade diameter of 8 inches or less) (OSHA Standard §1926.1153, p 3):

For tasks performed outdoors only:
• Use saw equipped with commercially-available dust collection system.
• Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
• Dust collector must provide the air flow recommended by the tool manufacturer, or greater, and have a filter with 99% or greater efficiency.

OSHA has stated that “full and proper implementation” of the specified engineering controls listed in Table I “satisfies the employer’s duty to achieve the PEL;” wearing respirators [dust masks] or further exposure monitoring is not needed. (OSHA Final Silica Rule 2016-04800)
What about dust exposure plans and training? James Hardie understands that jobsite safety is one of your most important responsibilities, and can assist with getting you the support you need to comply with the revised silica regulation. We have been working with industry safety and industrial hygiene experts and have developed exposure plans and training materials that are available upon request to help builders, contractors and subcontractors determine when Table 1 controls are needed and how to comply with the updated rules. What if I have other questions? As always, you can reach out to your local James Hardie rep if you have any additional questions. Also, James Hardie has established as a resource for information about using fiber cement products.

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