Tag Archives: sawdust

The Four Dangers of Sawdust

Sawdust happens. If you are a prop carpenter, or you do any sort of carpentry in your shop, you will produce sawdust. There’s been plenty written about maintaining the dust in your shop; that is, providing adequate ventilation in your shop,  hooking your tools up to dust collectors, hanging dust filters above larger power tools, and wearing dust masks when necessary. That’s all important, but this post is about dealing with the dust that is left. Sawdust creates four hazards:

  • Slip hazard
  • Health hazard
  • Fire hazard
  • Tool damage

Slip hazard

When you have a fine layer of sawdust on the ground, it reduces your traction. It is challenging enough to run a full sheet of plywood through a table saw. Don’t compound the struggle with slipping and sliding around on the floor. On lighter-colored floors, a thin layer of sawdust can be almost invisible and still cause slips and falls.

Health hazard

When you allow dust to hang around, everytime you drop a piece of wood or a prop, you will raise a cloud of dust. A lot of tools, especially routers and sanders, kick out a stream of air which will also blow sawdust into the air, and ultimately, into your lungs.

Fire hazard

Ideally, your shop will be set up for seperate metal and wood areas. In reality, this is not always possible, especially with larger props which cannot be moved to the metal area, or props constructed with both wood and metal. Grinding throws out hot sparks which disappear quickly, but if they find a pile of easily-combustible sawdust, they may begin to smolder and even catch fire. More dangerous is welding around sawdust. I’ve seen plenty of small fires begin from the johnny balls that fly out of a welder and roll into a pile of dust.

Tool Damage

All wood, even kiln dried, contains a minute percentage of moisture. When you turn the wood into dust, it allows the moisture to be released more easily. If you let even a thin layer of sawdust remain on your tools, the moisture will eventually begin to rust the metal parts. It makes no sense to spend hundreds or thousands of dollars on a tool with a precision-machined metal table only to let sawdust rust it away into a rough surface; especially when it takes about two seconds to brush the sawdust off.

Too much sawdust
Too much sawdust

Friday Errata

Sorry for the scant list of links today; I have to get back to budgets and sourcing and stuff. I have some pretty cool projects in the works, though, which I will be showing off on this blog in the coming weeks.

Remember how California was considering legislation to make flesh-detection technology (like the “Saw-Stop”) mandatory in all table saws sold in the state? Well, it looks like that bill is dead. So, for now at least, you do not have to worry about your new table saws becoming several hundred dollars more expensive to protect untrained hobbyists.

This M*A*S*H site has a few articles about some of the more iconic props from that series, such as this one on the appearance and evolution of the homemade still. Lots of photographs illustrate the story of this wonderfully intricate prop.

Any practical use by us prop makers is probably some years off, but this article claims that wood pulp is the new wonder material. Nanocrystalline cellulose (NCC), which is processed from wood pulp, not only has a strength-to-weight ration which is 8 times greater than stainless steel, but it is also transparent and can be made from waste material (sawdust), recycled wood or even twigs and branches.

Is MDF really that bad for you?

I’ve run across shops and artisans who tend to avoid Medium Density Fiberboard, or MDF. MDF is an engineered lumber product made of sawdust bonded together with a urea-formaldehyde adhesive. When you work with MDF, the dust you release also contains this formaldehyde, which you may end up breathing. So is that really that bad? The short answer is “yes, with a but”, while the long answer is “no, with an if”. Like any other substance or material used in a props shop, the safety of using it is dependent on knowing the risks and possible hazards and taking the appropriate precautions. After all, people can safely work with plutonium if their shop is set up correctly and they wear the appropriate gear.

Let me start off by saying yes, you should avoid breathing MDF dust. Formaldehyde is suspected of being a carcinogen, and MDF has some of the highest concentration of urea-formaldehyde adhesives out of all the engineered wood products that use it. Other products which use UF adhesive include hardwood plywood and particle board. Some products, such as softwood plywood and oriented strand board, use phenol-formaldehyde resin which emits much lower concentrations of formaldehyde. Nonetheless, when working with these products, you should have appropriate dust collection at the source of dust creation, proper ventilation and air filtration, and wear an appropriate personal respirator (a NIOSH-approved dust mask for particulates) when sawing or sanding.

So if it’s unwise to work with MDF without proper safety precautions, why am I asking the question in the title of this post? Here’s what I’ve seen; some shops avoid or even downright ban the use of MDF because of what they’ve heard about UF adhesives. This is absurd for several reasons. First, all materials are “bad” to some extent. A better way to phrase that is to say that all materials require you to understand what the potential hazards are and how to minimize them. If you are barbecuing in a grill, you know there is a potential for things to catch fire, so you have a fire extinguisher close by. If you understand why MDF is potentially harmful, then you can figure out how to minimize those harms; if your shop is unable to minimize those harms, than its use should be avoided.

My second point is this: if a shop avoids MDF because the dust gets in the air and employees breath it, it implies a larger safety issue. While formaldehyde is a suspected carcinogen, sawdust itself is a known carcinogen. Let me repeat that: sawdust is a known carcinogen (see here). If you allow sawdust to fill the air of your shop, you are basically filling your shop with carcinogens. So a shop or person that avoids MDF because the dust gets in the air is still allowing the dust from other products to fill the air, which is just as harmful to breath as MDF dust.

If you work with lumber of any kind, the proper precautions include dust collection at the source, ventilation in the whole shop, and the use of a personal respirator. These are the exact same precautions you need for using MDF. Also, the proper safety protocol in a shop is to keep track of all substances which you may be exposed to and take the recommended precautions to minimize exposure.

Thus, avoiding MDF in a wood-shop implies that not only does one not know proper safety protocols, but that one is exposing workers to other potentially hazardous dust. So my question, “Is MDF really that bad for you?”, has the same answer as every other substance. If you know the potential harms and how to minimize them, then it is no more “bad” than any other hazardous and toxic material you work with to build props. In other words, the proper question isn’t whether MDF is “bad” (it is, but so is everything else you use), it’s whether your safety procedures are bad.