Wood dust can explode in dry or wet state: Report

B.C. sawmill study makes surprise finding on using moisture to prevent deadly explosions

Wet wood dust is just as explosive as
dry wood dust, a report shows. 

The smallest-sized wet wood dust is just as explosive as dry wood dust from B.C. Interior sawmills, according to a report prepared by FPInnovations for the provincial sawmill sector.

The finding raises questions about the usefulness of misting at sawmills. It was part of a first-of-its-kind study in British Columbia ordered after a pair of deadly sawmill explosions in the province last year that killed four workers.

“It was assumed moisture would be a bigger factor,” said Darrell Wong, one of the report’s authors. He is a manager of FPInnovations, the non-profit forestry research centre at the University of B.C.

But Wong said more study must be done before sawmills should consider jettisoning misting systems. Misting systems have a secondary function of knocking wood dust out of the air.

Wood dust suspended in the air was confirmed as the fuel source for the two explosions by WorksafeBC, the province’s chief workplace safety agency.

As part of the new study, hundreds of dust samples from 18 sawmills were analyzed, with some samples sent to Chilworth Technologies, a lab in Princeton, N.J. that determines how explosive substances are.

The report has been made widely available through forest industry associations and the United Steelworkers, which helped fund the study. WorkSafeBC is also helping to distribute the report.

The study also found there is not much difference among the explosiveness of various types of wood dust of timber, including type of wood (spruce, pine, fir, Douglas fir or cedar) and timber killed by the mountain pine beetle. That suggests timber killed by the beetle has not had its properties changed to make it more explosive, said the report.

But the report said the milling of beetle-killed pine may create more dust or dust that is easier to raise into a cloud than other woods. Among the factors needed to create a dust explosion is fine particles suspended in the air.

FPInnovations applied two criteria to determine which areas in the sawmills were at greater risk of an explosive hazard: the accumulation of wood dust at a rate of greater than one eighth of an inch in an eight-hour shift and samples that have more than 40 per cent of particles that were 425 micrometres (just under half a millimetre) or less in size.

Just 20 wood dust samples met those criteria, with 14 of those from mills that were processing beetle-killed timber. A majority of these samples were collected from under or near conveyors and in basements.

A sawmill explosion at Babine Forest Products near Burns Lake on Jan. 20, 2012 killed two workers. An explosion at Lakeland Mills in Prince George on April 23, 2013, killed another two workers. Dozens more workers were injured in the two explosions and fires.

This article was edited for length. Source: The Vancouver Sun

Keep wood dust in check

Industrial air cleaners like Electrocorp's Dirty Dog
help remove dust and fine particles and more.

Wood dust is not only an explosive hazard, it can also affect the health and well-being of workers, especially over the long term.

Electrocorp offers highly efficient air purifiers for wood shops and sawmills, which help remove airborne wood dust particles and other contaminants.

With cleanable bag filters and washable pre-filters, these air cleaners can be mounted on the ceiling or placed on the floor.

For more information, contact Electrocorp.

New suggested limits for fine particle levels in the workplace

Fine particles can penetrate deep into
the lungs and cause health problems.

The finest particles are the most dangerous – they can be inhaled deeply into the lungs and cause inflammation as well as a wide range of health problems for certain individuals.

The dangers are compounded when workers are exposed to fine particulate matter at the workplace, but certain guidelines and threshold values are in place in most countries to protect the health and safety of those workers.

A subdivision of the German Research Foundation, the Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, has made important changes to the 2011 MAK and BAT Values List and recommends reducing the general threshold limit value for dust.

The recommendations contain new data on a total of 82 substances and come in response to recent studies, which have determined that dust can be carcinogenic at certain exposure limits.

The Commission determined a new MAK value of 0.3 mg/m3 for the general threshold limit value for dust (in German: Allgemeiner Staubgrenzwert), and bumped the granular biologically long-lasting dusts (GBS), which penetrate deep into the lungs upon inhalation, into Carcinogenicity Category 4.

This category identifies cancer-causing materials that do not increase cancer risk in humans if the corresponding MAK value is not exceeded.

MAK values indicate the amount of a substance – be it in the form of gas, steam or aerosol in the air at the workplace – that will not cause long-term damage.

The Commission applied a procedure for the calculation of the MAK values from animal experiments with oral intake of substances that is similar to that being used on the European level (REACH). The review of 24 values affected by this procedure resulted in a reduction for 11 of the substances. The rest remained unchanged.

Read the entire press release here.

Particle and chemical pollution in the workplace

Electrocorp has designed industrial-strength air filtration systems for heavy-dust environments and workplaces where indoor air quality poses a health and safety concern for workers.

DirtyDog Series: Cleaner air

Some recommended units:

DirtyDog Series
The DirtyDog dust collector is engineered to reduce dust levels by 70-90% to provide healthier, cleaner air in workplaces such as body shops, workshops and woodshops.
Comes with a washable pre-filter, a cleanable bag filter and optional HEPA filter. Pressure switch indicates a filter change. Can be hung from the ceiling or placed on the floor.

AirMarshal air filter

AirMarshal Series
This air cleaner is a powerful, portable unit for controlling dust particles or chemicals, gases and odors. Variable speed, replacement indicator light for the HEPA filter. Comes with a 24 to 36 lb. activated carbon filter, medical-grade HEPA, ProDense pre-filter and can be equipped with a special hose, exclusive carbon blends and electrostatic particle filter. Negative air ready.

AirRhino air cleaner

AirRhino Series
The AirRhino is one of Electrocorp’s most versatile and cost-effective units and can be switched from particle filtration to chemical, gas and odor adsorption right on site. Comes with a medical-grade HEPA filter, a ProDense pre-filter, a special dust filter an activated carbon filter and can accommodate a UV germicidal lamp, a bag filter for large particles and custom carbon blends.

Electrocorp specializes in providing customized air filtration solutions to many different industries, including woodshops and auto body shops and garages. For more units and more information, contact Electrocorp at 1-866-667-0297.
  

Officials to investigate health and safety risks for woodworkers

Woodworking involves many
health and safety risks.

Health and Safety officials in the UK will be evaluating the occupational risks for those in the wood-working and furniture-making industries, according to a recent article in the Guardian.

It has been 10 years since they last checked the risks officially, but a growing number of nasal cancer cases reported in longtime woodworkers prompted the new investigation.

Doctors say that woodworkers face 70 to 80 times the risk of a particular for of nasal cancer, which may develop decades after exposure to wood dust. Many other woodworkers report developing asthma as a result of their exposure to wood dust.

Workers are exposed to wood dust of a certain size and it is people who are sanding or lathing wood in conditions where they have to have quite a long exposure that they can develop this particular form of cancer, doctors said.

Often, woodoworkers are unaware they have nasal cancer until it is in an advanced state. Symptoms could be non-specific, including a blocked or runny nose with a bit of blood.

Source:  The Guardian

Woodworkers' health and safety risks

Apart from the noise, tools and other safety concerns, many of the risks associated with wood shops are connected to the air they breathe.

Wood dust, mold and fungus, sap and oils, chemical additives, and toxic solvents and adhesives can cause respiratory damage to woodworkers. Wearing a face mask often isn’t enough to stop the airborne toxins from affecting the woodworkers.

Along with sufficient ventilation and personal protective equipment, wood workers can benefit from an industrial-strength air filtration system for woodshops that is designed to handle a lot of fine dust.

It’s important to note that a simple air filter would not suffice. Filters would become clogged quickly. With a special bag filter option designed for large particle filtration, Electrocorp products such as the Dirty Dog or the I-6500 with Cyclone attachment are well equipped to work in environments with heavy sawdust or drywall dust.

The bag filters are easy to clean and reusable. This is an excellent option for situations where a HEPA filter would become blocked too quickly to be effective.

Contact us for more information: 1-866-667-0297.