100% silica free

The Danger Of Silica in Engineered Stone Surfaces

Challenges for the Stone Industry in the US

History

Silica in Engineered Stone

Engineered stone is increasingly being used for countertops due to its esthetics and durability. However, due to its high silica content, this material is causing a health crisis in the USA.

When engineered stone is cut, ground, or polished, fine silica dust particles are released into the air. When inhaled, these particles can lead to serious health problems, including silicosis, lung cancer and chronic obstructive pulmonary disease (COPD) (1).

This article looks at the latest research on silica in engineered stone, examining the associated health risks, recent regulatory developments and the measures being taken to address this growing problem.

Health Effects Of Silica Exposure From Engineered Stone

Engineered stone countertops are made from crushed quartz bonded with a resin binder. Although they are esthetically pleasing and durable, they contain a significantly higher level of crystalline silica compared to natural stone (2).

Crystalline silica comes in two main forms: amorphous and crystalline. Amorphous silica is chemically similar to glass and poses less of a health risk, while crystalline silica is the harmful form when inhaled (1).

This poses a serious health risk to workers involved in fabrication processes, especially those who cut, grind and polish the stone, as these activities generate significant amounts of respirable crystalline silica dust (RCS).

What is Silicosis?

One of the most serious health risks associated with exposure to crystalline silica is silicosis, an incurable lung disease. Silicosis occurs when silica particles are inhaled and become lodged in the lung tissue. This leads to inflammation and scarring that increasingly limits the lungs' ability to take in oxygen (1).

Over time, this can lead to symptoms such as shortness of breath, persistent cough, eventually leading to respiratory failure (2).

Other Respiratory Risks

In addition to silicosis, exposure to crystalline silica has also been linked to other respiratory diseases, including COPD and lung cancer (1).

Studies suggest that workers exposed to crystalline silica dust have an increased risk of developing lung cancer, and this risk increases significantly with prolonged exposure (1).

legislation

New Legislation for Engineered Stone Products

Authorities in the US have recognized the serious health risks associated with exposure to silica and are working to implement new laws and regulations.

California's Efforts

In December 2023, California took the lead and became the first state to implement an interim emergency health standard (ETS) to protect workers in the stone processing industry from exposure to silica (9).

This ETS mandates enhanced safety measures, improved worker monitoring and a robust reporting process (9).

In December 2024, the California Occupational Safety and Health Standards Board voted unanimously to make this ETS a permanent standard, reflecting the growing recognition of the serious health risks posed by silica in cast stone and the commitment to protecting workers (9).

OSHA's Initiatives At The Federal Level

In 2023, the federal Occupational Safety and Health Administration (OSHA) launched an initiative to improve enforcement and compliance assistance in the engineered stone fabrication and installation industry (10).

This initiative is designed to ensure that employers comply with safety standards and provide workers with the protection they need 11. OSHA also issued a final rule to improve the protection of over 2 million workers exposed to respirable silica dust. This rule aims to curb lung cancer, silicosis, chronic obstructive pulmonary disease and kidney disease by limiting workers' exposure to respirable crystalline silica (12).

In addition, OSHA has announced a new program with comprehensive guidance and resources to raise awareness, improve education and implement effective control measures to reduce workplace exposure to silica dust (13).

The MSHA's Final Rule for Miners

In April 2024, the Mine Safety and Health Administration (MSHA) published a final rule to protect miners from silica dust exposure (15).

This rule lowers the permissible exposure limit for respirable crystalline silica and requires mine operators to implement engineering controls, establish medical surveillance programs, and update respiratory protection standards (15).

silica free stone

Legal Cases and Lawsuits

The health crisis caused by silica exposure in the engineered stone industry has led to numerous legal cases and court proceedings.

Lawsuits Against Manufacturers

Workers and their families have filed lawsuits against manufacturers of engineered stone for allegedly failing to provide adequate warnings about the dangers of silica dust exposure (6).

These lawsuits seek compensation for medical expenses, lost wages and other damages, including pain and suffering (20).

Specific legal claims being made in these lawsuits include negligence, failure to warn, design defect, fraudulent concealment and breach of implied warranty (20).

Landmark Cases

In a landmark case in 2024, a Los Angeles County jury awarded $52.4 million to a stone fabricator who contracted silicosis after 15 years of working with artificial stone products (21).

This case set a precedent that manufacturers can be held accountable for failing to warn about the dangers of their silica-containing materials (21).

This landmark case could potentially lead to a wave of similar lawsuits and increase pressure on manufacturers to take responsibility for worker safety (6).

Efforts to Find Safer Alternatives

In the face of mounting lawsuits and growing concerns about the health risks of engineered stone, manufacturers are looking for safer alternatives. Companies such as Cosentino and Caesarstone have begun launching engineered stone products with significantly lower crystalline silica content.

Alternatively, companies like OK Stone Engineering in Texas is manufacturing 100% silica free engineered stone in partnership with Breton, the world leader in engineered stone manufacturing.

Bioquartz® is a 100% silica-free engineered stone developed by Breton that serves as an alternative to conventional quartz in the production of engineered stone.

The product has the same technical and esthetic properties as conventional quartz while being safer for human health. The technology is a patented process using vacuum vibro-compression with synthetic aggregates.

Engineered Stone - A History

Engineered stone has become a ubiquitous material in modern construction and design, prized for its durability, versatility and esthetics. The journey from an experimental concept to a staple in residential and commercial spaces is a fascinating story of innovation, perseverance and adaptation.

What is engineered stone?

It's important to understand what engineered stone is and how it differs from natural stone, including those that are sometimes mislabeled. Engineered stone is a composite material consisting primarily of crushed stone bonded together by an adhesive, usually a polymer resin. This distinguishes it from natural stone such as granite or marble, which is quarried directly from the earth. It is important to note that while quartz glass is often marketed for its durability and low maintenance, it is not completely maintenance free and can still be susceptible to staining, chipping or heat damage if not cared for properly.

To make matters worse, there is often confusion on the market about the labeling of natural stone. For example, some marbles and sandstones are incorrectly labeled as "soft quartzite"," although they have different properties to genuine quartzite2. This underlines the need for clarity when discussing engineered stone and its relationship to natural stone. The engineered stone category includes several types, including:

Engineered quartz: This is the most common type, made from crushed quartz crystals bonded with resin. Due to its superior hardness and resistance to scratches and stains, it is mainly used for kitchen worktops.
Polymer concrete: This type of concrete consists of a mixture of aggregates and polymer resin.
Processed marble: Crushed marble forms the basis for this type of concrete, which is also bound with resin. Engineered marble is often used for interior flooring and wall cladding due to its cost efficiency and wide variety of colors and patterns4. The specific application of engineered stone depends on the type of stone used.

Marcello Toncelli

The story of engineered stone begins in the early 1960s in the Veneto region of Italy. Marcello Toncelli, an ambitious inventor with a vision to change the stone industry, founded Breton S.p.A. in Castello di Godego. Driven by the desire to create a material that had the esthetic appeal of natural stone but with better consistency and predictability of color and pattern, Toncelli began years of research and experimentation.

This quest for a more consistent and durable material was one of the key drivers behind the development of engineered stone. His initial efforts focused on combining crushed stone with resin, a process that presented numerous challenges. Early versions were prone to porosity due to air bubbles trapped in the resin.

Toncelli's ingenuity led him to a rather unconventional solution: he used a hot water bottle to create a vacuum and eliminate the air bubbles. While this rudimentary method was effective, it needed to be scaled up for industrial production.

Overcoming challenges and refining the process

While Toncelli's hot water bottle method proved effective, it was clear that a more scalable solution was needed for mass production. This led to further research and development, culminating in the invention of vibro-compression vacuum technology.

In this innovative process, a mixture of crushed stone and resin is poured into elastomer molds on a moving belt. The mixture was then heated and compressed under vacuum in a large press, with the vibration ensuring a homogeneous and non-porous slab. This technology revolutionized the production of cast stone as it enabled the manufacture of durable slabs with consistent quality and appearance.

By the end of the 1970s, the first Bretonstone plant capable of producing large slabs was in operation. This marked a turning point and paved the way for the mass production of cast stone.

Sources

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