Combustible dust is on OSHA’s radar. If you run a woodworking company, it should be on yours also.

OSHA has scheduled two meetings to discuss combustible dust workplace hazards. (See accompanying box for details.) OSHA will use comments from these meetings and responses to an Advance Notice of Proposed Rulemaking in developing a comprehensive standard addressing fire and explosion hazards of combustible dust.

In October, the OSHA Combustible Dust ANPR was released, containing 69 questions that need to be addressed before a formal rulemaking. There is a 90-day window to comment that ends Jan. 19, 2010.

The Status Report on Combustible Dust was released the same week.  Jamie Scott of Air Handling Systems in Woodbridge, Conn., believes this report will be of much more interest as it singles out the inspections through the National Emphasis Program (NEP) on wood products by emphasizing the number of inspections that affect the wood dust-producing companies. OSHA used this program to do a preliminary study on combustible dust and used the “general duty clause” if any violations were found.

Combustible dusts are fine particles that could present an explosion hazard in certain conditions. Dust explosions can occur in many places where there is oxygen, heat and dust (the fuel) in sufficient quantities, and some kind of confined space. Possible new rules could make it difficult to meet new standards designed to minimize such explosions.

A combustible dust hazard exists in many different industries, including woodworking.

OSHA’s Combustible Dust National Emphasis Program applies to 64 industries. In addition to wood products, the program covers chemical, plastic, textiles and many other industries. 

Sugar dust explosion

Recent attention was focused on this issue not because of woodworking, but from a large sugar dust explosion at Imperial Sugar’s Port Wentworth, Ga., plant in February 2008 that killed 14 and injured many more.

Woodworkers aren’t aware as they should be of what could potentially happen, says Scott, who adds, “Woodworking is on OSHA’s radar screen.”

Tony Supine of Camfil Farr APC, Jonesboro, Ark., says that the sugar refinery incident, was “the straw that broke the camel’s back” for OSHA, and that the National Emphasis Program was made in response to that.

There are several existing National Fire Protection Assn. standards that apply to overall dust/combustible dust situations (NFPA 654) and a standard that is specific to the prevention of fires and explosions in wood processing and woodworking facilities (NFPA 664).

 Supine doesn’t expect OSHA to deviate greatly from the existing NFPA standard.

“What I see them doing is taking these standards and making them their own,” he says.

“If your (company is) following the NFPA guidelines and standards, then you’re going to meet the national emphasis program,” he says.

There may be exemptions for smaller shop sizes. A business in a building smaller than 5,000 square feet, for example, or with fewer employees or collecting a smaller amount of air may be exempt.

“That is part of my concern from a very high level – if the standards are too strict will it be cost prohibitive to meet them?” asks Scott.

OSHA looks at accumulation of dust, and there are several measurements. One simple rule of thumb, Supine says, is that if you can see your footprint, then you’ve got an issue. 

Inspection program

OSHA introduced its Status Report on Combustible Dust National Emphasis Program in October. OSHA began this program in October 2007 to inspect factories that generate or handle combustible dusts that pose a potential deflagration/explosion or other hazard.

There were some 280 dust fires and explosions in U.S. industrial plants over the past 25 years, resulting in 119 deaths and more than 700 injuries, according to a report from the Chemical Safety Hazard Investigation Board.

Wood products accounted for about a quarter of the inspections from October 2007 to June 2009. OSHA found 4,900 violations in all industries in this period, including many other than combustible dust, including the use of compressed air to clean accumulated dust, which can create a hazard.

OSHA is encouraging training of employees, and also plans to continue fines for violations. 

Violations examples

Average number of violations per NEP inspection was about three. Here are some examples of violations:

--Dust collectors were located inside of buildings without proper explosion protection.

--Horizontal surfaces were not minimized to prevent dust buildup.

--Ductwork was not adequate to maintain a velocity of at least 4500 ft./min.

--Regular cleaning routines not established for walls, floors and horizontal surfaces such as ducts, pipes and beams.

--Company did not provide adequate maintenance and design of dust collectors systems.

WMMA task force

The Wood Machinery Manufacturers of America formed a task force on industrial dust to monitor the legislative and regulatory developments (there is also potential legislation in the U.S. House of Representatives).Air Handling’s Scott says the role of the WMMA Public Policy Committee’s Industrial Dust Task Force has been to inform and educate its own members on how potential regulations may affect their customers, since many woodworkers are not aware of this issue.Scott says that woodworkers need to be aware of the problem, and if they stay ahead of the issue, they’ll probably be all right. “There’s definitely an opportunity for woodworkers to comment on it.” For more information on this committee, contact Jamie Scott at [email protected].

“It is not just a dust collection issue.  It is a housekeeping issue.  It is understanding what is combustible and what is not,” Scott says.“Woodworking companies often don’t realize they’re working with a combustible substance,” says Farr’s Supine. “Wood dust may not be as combustible as many other substances, (but) if they don’t have the proper dust explosion protection equipment, they have a danger as well.“Housekeeping…requires dust collection, and making sure that dust collector is compliant with the NFPA code. If woodworkers do those two things I don’t think they’re going to have an issue with anything that comes out from OSHA down the road.”

Dust control recommendations

OSHA doesn’t have a specific standard on combustible dust hazards, but there are several existing standards related to combustible dust, and recommendations for woodworkers.

--Use proper dust collection systems and filters

--Start a hazardous dust inspection, testing, housekeeping and control program

--Use surfaces that minimize accumulation of dust

--Provide access to hidden areas to allow inspection

--Minimize escape of dust from equipment and ventilation systems

--Regularly inspect for dust residues

--Use vacuum cleaners approved for dust collection

Source: OSHA