OSHA's Engineering Controls for Silica Dust

A recent study in the Annals of Work Exposures and Health examined the effectiveness of OSHA’s engineering controls for silica dust.

What is Silica?

Silica is a common mineral found in concrete, glass, mortar, brick, stone, and sand. Manufacturing, cutting, sanding, or drilling these materials can produce respirable crystalline silica, which is 100 times smaller than a grain of sand.

OSHA estimates that 2.3 million workers in the U.S. are routinely exposed to respirable silica. Inhaling this dust leads to an increased risk of several diseases. Among these are silicosis, lung cancer, kidney disease, and chronic obstructive pulmonary disorder, or COPD.

OSHA Standards

OSHA published two standards on respirable silica, designed to protect workers. In the construction standard, for example, OSHA suggested systems that deliver water to the cutting surface, shrouds, dust collection systems, and HEPA filtration. By implementing these controls, it is assumed that the levels of respirable silica will remain below the personal exposure limit, or PEL.

The Study

The study, mentioned above, challenges that assumption. Researchers took air samples from a construction site. They also took personal air samples from 19 workers at the same site over 13 days. The workers performed such tasks as core drilling, cutting with a walk-behind saw, grinding, and jackhammering. Researchers noted whether or not the workers were implementing the OSHA controls. Some did not.


The researchers found that over half the workers were exposed to respirable crystalline silica above the OSHA Action Level. And nearly one third of the exposures were above the PEL. One of the work site samples exceeded the PEL. The study suggests that OSHA's engineering controls for silica dust may not prevent hazardous levels of the dust. Workers performing certain tasks, along with the rest of the work site, face levels of silica dust above the PEL. In turn, they are at greater risk of developing one of the diseases associated with breathing silica dust.

Workers Fall Into Chocolate Tank

The Occupational Safety and Health Administration issued a serious citation and fine to the Mars Wrigley corporation after two workers fell in a tank used to manufacture chocolate. Emergency responders had to cut a hole in the bottom of the tank to free the workers. And both were taken to the hospital, one by helicopter.

Outside Contractors

The two workers were not employees of Mars Wrigley. Rather, they were outside contractors performing maintenance work on a vat used to make Dove chocolate. The tank was partially filled with chocolate at the time of the accident. 

OSHA Violations

The OSHA Violation Detail states that one of Mars Wrigley’s own employees was involved with “the control of hazardous energy” in the tank. And that the company failed to ensure that that employee understood “the type and magnitude of the energy for the task.” 

Additionally, entry into the tank is permitted. The two outside employees needed to verify that any flowable material in the tank was isolated prior to entry. The chocolate manufacturer failed to provide the two contractors, who were cleaning the vat, “with the correct energy control procedure or work authorization permit” required to safely enter and work in the tank.

Isolating Flowable Hazards

The techniques used to isolate confined spaces with flowable hazards are found in paragraph (b) of 29 CFR 1910.146. These techniques are blanking or blinding; misaligning or removing sections of lines or pipes; or a double block and bleed system.

Mars Fined

This incident at the Mars Wrigley plant occurred in June of 2022. After an investigation, OSHA levied a fine of $14,500 in December.

Workplace Safety

OSHA, part of the Department of Labor, is the government agency whose mission is to ensure workplace safety. They do this by enforcing their standards and providing training.

Caterpillar Incident

This past June, a worker at a Caterpillar foundry in Texas fell into a ceramic container of molten iron and was “immediately incinerated.” OSHA investigated the incident and determined that the foundry regularly exposed its employees to unprotected fall hazards. Workers routinely worked just a few feet away from large pots of super-heated iron. And Caterpillar had not installed guard rails or safety protections around the pots. The worker who fell in was, at the time, taking a sample of the molten metal, used to cast engine parts. 

Federal Regulations

Federal regulations require that employers address fall hazards. Employers might cover the hazard or put guardrails around it. Or they might provide personal fall arrest systems to employees. Caterpillar failed to do this. So OSHA cited them for the violation and proposed a fine of $145,027.

Federal regulations are not limited to fall hazards. OSHA standards address a wide variety of hazards, including loud noises, electrical hazards, exposure to radiation and gases, and heat stroke. OSHA requires employers to address these hazards. This makes the workplace safer for employees.

Employee Rights

Employees have the right to safety training and equipment, safe machinery, and protection from toxic chemicals. The OSHA Worker Rights and Protections website details these rights and more. It also explains when and how to file a confidential complaint about unsafe working conditions and how to request an OSHA inspection.


This OSHA News Release details the workplace safety investigation at the Caterpillar foundry.

OSHA's Frequently Asked Questions provides more information for employees about workplace safety.

META Blogs on Safety

Encouraging the Use of PPE

Poisonous Plants

EPA Lead Training

Hispanic Labor in the Construction Industry

National Hispanic Heritage Month in the United States begins on September 15th, and occurs at the same time Mexico, Central America, and Chile celebrate their independence from Spain. This is a month-long celebration of Hispanic contributions to the history and culture of the U.S. It offers us an opportunity to look at Hispanic contributions to the construction industry and some ways to better support Hispanic workers.

Hispanic workers are very important to the U.S. construction industry. In 2021, they made up more than 30 percent of the labor force. This is nearly double from 20 years ago: in 2001, about 16 percent of construction workers were Hispanic.

Yet Hispanics account for less than 20 percent of the U.S. population. So they are overrepresented in construction work. This is incredibly important, as there is a large labor shortage in the United States’ construction industry.

The numbers are even more clear-cut in Southwestern states. In Texas, California, and Arizona, for example, Hispanics are 61 percent, 55 percent, and 49 percent of the construction workforce, respectively.

The labor provided by Hispanic workers greatly contributes to the success of the construction industry. It is important for construction firms to help Hispanic workers feel less isolated from coworkers who don’t speak Spanish. Construction Executive, a magazine that covers the construction industry, has three suggestions to improve the work-life of Hispanic laborers: increasing Spanish language skills and signage across all levels of the industry; educating the public about career opportunities in construction and hiring a more diverse set of workers; hiring Hispanics from underserved communities and giving them the opportunity to reach more senior positions, where diversity is lacking.

Making these changes would recognize Hispanic contributions to the construction industry and help build a stronger, more diverse workforce.

See also:

Women in Construction 


National Hispanic Heritage Month

One in Three Workers in Construction Is Hispanic

Construction Labor Shortages

Construction Workforce in the Southwest

Support for Hispanic Workers

The EPA Updates Lead Training

The Environmental Protection Agency (EPA) recently updated its website and resources for trainers who offer courses in Renovation, Repair, and Painting (RRP) and in the Lead-based Paint Activities Program. With these updates, the goal of the EPA is to improve training in these fields. The goal of this training is to reduce or prevent lead exposure, including lead exposure in overburdened communities.

The EPA has reorganized its RRP homepage and provided links to updated model courses, RRP resources for trainers, and guidance on accreditation

Lead-based paint is very common in homes and buildings built before 1978. When renovation, repair, painting and lead abatement projects are done correctly, they can reduce or eliminate exposure to lead for both the workers completing the projects and the building's occupants. So it is important that workers receive proper training and trainers are knowledgeable on the most current work practices.

META Online Classes

META is dedicated to providing comprehensive and up-to-date training in lead, as well as asbestos, mold, and OSHA safety training. At META, we offer a 4-hour RRP Renovator Refresher course that is online. This course covers the health effects of exposure to lead-based paint and reviews safe work practices. META's RRP course also covers EPA and HUD regulations, record keeping, and other topics. 

Completion of this class leads to a 3-year certificate that is valid in 36 states. To renew your certificate at the end of this 3 year period, the EPA requires an in-person refresher course. META offers this and it satisfies the hands-on portion of the training.

You can take our online classes at your own pace and fit the course within your schedule. Sign up on our website today!

Women in Construction

It’s 2022 and the idea of jobs being gendered is a thing of the past. Women aren’t expected to be teachers and nurses and men aren’t expected to be doctors and laborers. One such field that was once considered to be a “man’s” job was construction work. That is far from the truth, considering the number of women in the construction field has increased by 50% over the last decade according to Fixr

Though the number has grown, females still only make up around 10% of all construction workers. That means on average if a construction company has 200 employees then only 20 of them are female. This shows the clear lack of female representation in the construction workforce. One way of getting women interested could be highlighting the benefits and advantages of construction work.


There are many advantages of working in construction, no matter your gender. Construction opportunities are endless, especially if someone is willing to travel for work. Traveling is also an advantage as it gives people the opportunity to explore new places. There are also a variety of roles in the construction industry such as laborers, managers, supervisors and more.

There are resources for women in construction including the National Association of Women in Construction (NAWIC). NAWIC was originally founded in 1953 as Women in Construction of Fort Worth then gained its national charter in 1955. NAWIC’s mission is to advocate for the value and impact of women builders, professionals and tradeswomen in all aspects of the industry. The construction industry is far from slowing down meaning there is plenty of space for females. Having females involved in all aspects of the construction industry is so important. Companies should strive to break the mold and create a more inclusive workplace. To find tips on how to bring women into the construction workplace, check out this article.