By Matt Warnock and Wade Vonasek

For the safety of workers, as well as machinery, a proper dust collection system is a necessary piece of equipment for any wood products facility.

Improper dust collection can be hazardous to employees health, as well as impair the performance of machinery in the shop.

No matter who you are, dust collection is an issue for any woodworking facility. Wood dust is an inevitable by product of manufacturing in the wood products industry. Unfortunately, the dust that is created in the manufacturing process creates a few problems for the wood products facilities. Excessive amounts of dust can clog up and cause damage to expensive pieces of equipment, but more alarming is the fact that wood dust can also pose health and safety hazards to employees.

The dust created when working with certain species of wood is a known carcinogen. For shops using MDF, particleboard or plywood, when working with those materials the dust contains the resins and other chemicals used in the creation of the board.

“The wood dust created by cutting, shaping and sanding wood is more than a nuisance,” says Eric Lowe, national sales manager for Dantherm Filtration Inc. “It can be a serious health hazard to both the health and safety if it is not properly controlled.”

“Anyone in a wood shop that does not wear a face mask or does not have an effective dust collection system knows what eight hours of breathing fine particulates does to your nose and mouth,” adds Scientific Dust Collectors’ General Manager Mike Gerardi. “You can see the haze in the air. You can taste it long after your shift is over. They realize that cannot be good.”

According to Lowe, there are a number of health concerns when working with improper levels of wood dust, including:

• Respiratory Effects: Respiratory effects are the primary health concern. Inhaling excessive dust can cause nasal irritation and bleeding, inflammation of the sinuses, wheezing, prolonged colds and decreased lung function. You can also develop an allergy or asthma from repeated exposure to certain wood dusts.

• Skin and Eye Effects: Skin and eye effects are also possible. Dermatitis and inflammation of the skin can occur from repeated wood dust contact. Symptoms include itching, redness or cracking of the skin. Wood dust can also cause eye irritation.

• Wood dust is a known human carcinogen: Occupational exposure to certain wood dust can cause cancer of the sinuses and nasal cavities.

Proper ducting is a necessity in ensuring the dust collection equipment maintains maximum efficiency.

More companies and groups are recognizing the need for proper dust collection. As new studies are conducted and more information reaches the public, more woodworking companies are opting to enhance their dust collection efforts.

“There has definitely been an increase in the awareness of the potential hazards of the materials found in today’s shops. Additionally, regulatory bodies like the Occupational Safety and Health Administration recognize that saw dust also can be a major slipping or tripping hazard,” says Rick Bush, product development manager for Festool USA.

“Everyone is concerned about maintaining a healthy environment,” agrees John McConegly, president of JDS Co. “More people are recognizing a need for dust collection.”
Of course, a proper dust collection setup is a key piece of equipment in any woodworking shop. Without proper collection, dust and wood chips will settle on any surface, including machines, floor and products. As with any other key piece of equipment, proper setup and maintenance is essential to ensure that maximum productivity is achieved.

Choose and Maintain the Right System

There are many factors to consider when choosing a dust collection system. Should there be one large dust collector for the whole shop or should there be dedicated dust collectors for individual machines? Should there be the option of adding additional machines to the dust collection system later? How fine of a filtration is needed? How should the system be laid out?

All of these factors — and more — can have a definite impact on the cost, effectiveness and usability of a dust collection system.

McConegly says it is important that customers understand the dust collection system they have and how it is set up. “How the system is laid out is important to performance. More pipe, smaller pipe and more bends equal reduced performance. Choking the performance with too many bends is similar to traffic movement on the interstate — with sweeping bends, rather than sharp turns, the air moves faster,” he adds. “A customer doesn’t need a bigger dust collector to be more effective, it could be a case of needing a more efficient ducting system.”

“A properly designed and sized system, which is installed with minimal air leakage, facilitates a smooth operation,” agrees Jamison Scott, Air Handling Systems’ director of marketing.

Efficiency is a must in dust collection equipment. As the technology progresses, dust collector manufacturers are introducing new machines that use less energy while being more effective. There has also been a switch to smaller dust collectors that are dedicated to individual machines, as many woodworking shops do not run all of their machines all day.

“Controlling the power has huge benefits,” explains Steve McDaniel,

As the technology progresses, dust collector manufacturers are introducing new machines that use less energy while being more effective.

K & B Duct’s vice president of the Kirk & Blum product division. “For example, a 10 percent reduction in the fans’ speed typically nets a 20 percent power savings, and a 20 percent reduction nets a 40 percent savings.”

However, this can all mean very little if the dust collection system is not properly maintained. A clogged or malfunctioning system can severely impair the dust collection capabilities, which can mean more particulates in the air.

“Dust collection is easy to take for granted until it stops working,” says Bush.

“The key to smooth-running dust collection systems is routine maintenance and proper sizing of the system,” says Lowe.

“To prevent dust collection systems from becoming the source of downtime and compliance issues, it is imperative that you budget for a professional preventative maintenance program. Service professionals can perform your routine maintenance and identify and correct any small problems, before they become big headaches,” Lowe adds.

Filtration is another factor that needs to be considered when talking about dust collection and maintenance. Improper filtration can be putting dust back into the air or make the dust collector less efficient. And it almost goes without saying that the filter media needs to be changed regularly.

“The most common performance problem we see is insufficient filter area for the air volume rating (cubic feet per minute) of the dust collection system. For chronic complaints on low air performance and premature filter blinding (clogging) the first thing we look for is too high an air-to-cloth ratio. Low air-to-cloth ratios allow air to move slowly across the filter media, keeping the pressure drop — or energy loss — to a minimum,” says Robert Witter, owner, Oneida Air Systems Inc.

“As filters load with dust cake, pressure drop across the filter media increases and the overall system airflow decreases. Keeping pressure drop across the filter low will result in less overall system energy costs and the dust collection at your woodworking tools will be better,” Witter adds.

Therefore, with the proper system and a regular maintenance schedule, it is possible to significantly reduce the amount of wood dust that employees are exposed to.

Controlling Exposure

Regardless of whether wood dust is a carcinogen, most would agree that exposure to it should still be avoided or minimized, and that a dust collection system is essential to a woodworking facility. But there are other factors to consider as well, such as proper installation of the dust collection system and improvements that can be made to the system once installed.

McDaniel stresses proper planning. “Plan ahead for future expansion by working with an energy management system and/or building in additional capacity,” he says. “Most people buy for the present and seriously jeopardize the integrity of the system in just a few years by adding more on the system. A CNC router typically requires 3,500 CFM. If not planned for, this can put a huge strain on the entire system. The customer can save himself a lot of headache and a tremendous amount of money by thinking out two years.”

“Customers handling wood dust are looking to install a properly sized and properly functional dust collector,” adds Gerardi. “The customers that will be happy with their system for years to come will give some thought up front to their requirements, both short-term and long-term. They will work with experienced and professional companies and discuss the options that are available so that they make the best decision for their individual company.”

Capturing the dust at its source is also important. “Utilizing source capture technology is also a key component to effective removal and reduction of wood dust exposure by sizing the pickup points and ductwork to prevent dust problems in the plant and exposure to personnel,” says Lowe. “The protection of their employees is every company’s primary concern; however, proper dust collection systems also improve the process machinery’s output capability and extend equipment life.”

“The best way to control wood dust exposure is to collect the dust at the source before it is lost to the shop air where you risk breathing it in,” Witter agrees. “Second, use sufficient air volume (cubic feet per minute) at the woodworking machine to ensure that the wood waste is effectively entrained into the dust collection system. It is important that each machine that generates dust have the right diameter ductwork and the right volume of air.

“Third, use a separator to separate the bulky wood waste from the air stream as it enters the dust collection system. This is safer because it removes potentially destructive objects before they can enter the fan and is more efficient because airflow won’t be restricted by filter clogging, and filter cleaning is required only after extended operation. Fourth, have effective final filtration. Effective filtration requires two things: quality filter media and a sufficient quantity of filter media. The filter media should be tested and rated to filter a minimum of 99 percent of test material between 0.2-2.0 microns at 11 FPM face velocity,” Witter says.

Bush adds that sometimes more is needed than just a central dust collection system in the shop. “Besides Personal Protective Equipment (PPE) and large central collection systems, production shops still use portable power tools in many steps of production and fabrication,” he says. “Tying these portable power tools into a central system can be tricky at best, if possible at all. Portable dust extractors allow shops the ability to control the dust from even the smallest offenders for a more complete dust extraction solution.”

The Tulane Wood Dust Study, finished in 2005, concluded that breathing wood dust does not pose an adverse health risk to respiratory functions, as no significant adverse effects from wood dust were reported at facilities participating in the study.

After the Tulane Study, What’s Next?

A study completed in the Fall of 2005 at Tulane University on the potential respiratory health effects of wood dust exposure to woodworkers concluded that breathing wood dust does not pose an adverse health risk to respiratory functions as long as appropriate measures were taken, based on the findings that no significant adverse effects from wood dust were reported at participating facilities. The $1.9 million study was commissioned by the Inter-Industry Wood Dust Coordinating Committee (IIWDCC), a consortium of 19 wood products trade associations.

“The results were surprising in that we did not really see any effects with respect to exposure to wood dust,” says Dr. John Festa, PhD, senior scientist for the American Forest and Paper Assn., one of the sponsors of the Tulane study. “The study was designed to look at exposure response, but at the levels encountered in the study, the Tulane researchers did not see effects over a fairly broad range of exposures.”

Since the Tulane study there has not been significant action or research in regards to the effects of wood dust, although the International Agency for Research on Cancer (IARC), which reviewed wood dust in 1994, will be conducting an updated review in March 2009 as part of a broader review of substances, according to Festa.
Festa says that the results of the Tulane Wood Dust Study have been published in two scientific peer-reviewed journals, and that the results will be helpful in regards to future studies. “The Tulane Study is the largest of its kind conducted to date on non-cancer respiratory effects,” he says. “The data from the study should provide a sound basis for standard-setting.”

According to Festa, one of the goals of the study was to ensure continued worker health and safety. Though he is not aware of any current activity at the Occupational Safety & Health Administration (OSHA) on wood dust, he says that the Carpenter’s Union was kept informed during the study. “We kept the Carpenter’s Union apprised of the study during its conduct, and briefed the Union on the findings after the study was completed,” he says. “We have not heard of a call by the Union for tighter standards based on this study.”