Every woodworker needs to wear a personal respirator at some point during the woodworking process. I use mine primarily when I am sanding or using my router. My dust collection system does a good job of catching most of the dust, but it's not perfect. I use one of the best personal respirator in the market today, a 3M 7500 series respirator. Let's take a look at what makes the 3M 7500 work so well in the shop.
The 3M 7500 series respirator comes in three sizes (Small, Medium, Large). For a respirator to work properly, it must create an airtight seal around the user's mouth and nose. In order to do that the respirator must roughly match the size of the user's head. That's why 3M sells three different models in the 7500 series. They are all functionally equivalent; the only difference is the size of the mask.
After using the 3M 7500 for a while, I understood just how badly one-size-fits-all respirators actually fit. A respirator, when sized properly, should be hardly noticeable to the user. That's exactly what the 7500 series respirators manage to do.
The 7500 series uses two straps to hold the respirator in place. One connects to a plastic ring that sits on the top of the user's head. The other connects behind the neck. The ring above the head supports most of the weight of the respirator and cartridges. It distributes the weight over a large area, which creates both a secure and confortable fit. The strap behind the neck keeps the lower part of the respirator from tilting forward. It hardly carries any tension.
Both straps avoid the ears of the user entirely. At no point does any part of the respirator touch the ears. This simple feature alone makes the 7500 series the respirator to wear. Unlike my last respirator, which was basically hanging from my ears, the 7500 series does not create any fatigue in the ear area. The straps do not interfere with the ears muffs in the slightest. Wearing safety glasses with the respirator is also not a problem.
The straps are grey in anticipation of sweat and dirt accumulation. Only the neck strap makes contact with skin. The strap on the top of the head sits on top of the user's hair.
The seal of the 3m 7500 series in near perfect; or perfect according to my limited measuring capabilities. The respirator edges are folded over around the area of the seal. The resulting flap sits on the skin of user and creates an air tight seal. The rubber in this area is soft to increase performance and comfort. 3M increased the area of the flap to create a comfortable fit. On other respirators this area is thin and hard.
If I plug the exhaust of the respirator and breath out normally, the air I exhale fills the respirator and eventually lifts it of my face. I cannot feel or hear any air escaping anywhere until the seal breaks.
For sanding MDF and other stock I equip my respirator with particulate filters (3M 2091 Particulate Filter). While wearing the mask I cannot smell the distinct odor of MDF in the slightest. All I smell is the rubbery smell of the respirator. While that's not irrefutable proof of the respirator working perfectly, it's a first step towards doing just that. It's also very reassuring.
Breathing while wearing the 3M 7500 series respirator is almost effortless with no filter attached. It is just slightly harder to exhale. After a few minutes the respirator disappears from my mind.
While designing the 7500 series, 3M went beyond normal breathing patter. Spare exhale events by the user have been a problem for respirators. The large amounts of air the user produces in a very short amount of time cannot pass through the filter fast enough. The user ends up blowing the respirator off their own face.
The 3M 7500 manages this event with the extra-long flap in the seal area. Just like with other respirators the 7500 series does lift off the user's face when he exhales sharply. The flap, however, holds the seal longer allowing the respirator be suspended in front of the user's face for a short time. As the air escapes through the filter, the respirator sinks back into position again. It's still possible to pop the respirator of your face, but it takes a lot more effort to do so.
It's features like this that make a respirator truly comfortable. While wearing the 3M 7500 series, the operator does not have to worry about breathing correctly. It's the respirator that adapts to the situation.
The exhaust of the 7500 is pointed straight down. This can be an advantage when you do not want to disturb the area right in from of your face. I have not found a situation that demands the feature, but it's worth taking a note of.
The 7500 series support a wide range of cartridges for a wide range of operations. The inexpensive dust filters (3M 2091 Particulate Filter) are a good option for woodworking which requires mostly particulate filtering. Most of the time my respirator is equipped with these filters. They hardly limit the amount of air passing through. For finishing work or other more demanding task I switch to heavier, more restrictive filters.
- 3M 2091 Particulate Filter
- 3M 2097 P100 Organic Vapor Filter
- 3M 6006 Multi Gas/Vapor Cartridge
- 3M 6022 Organic Vapor Cartridges
- 3M 60923 Organic Vapor/Acid Gas/P100 Cartridges
- 3M 60926 Multi Gas/Vapor/P100 Cartridges
- and may more...
At about $20 the 7500 series has a built-in lifespan. It's not expected to last forever. Nor should you want it do. The rubber is going the get harder, the straps are going to accumulate dirt, and the valves are going to deteriorate. All that is by design. In a residential environment you should expect to get years of use out of the 3M 7500 series respirator. I don't have any data on well the respirator performs in a commercial environment. At any rate, the 3M 7500 series is built as well as any respirator in this class.
I think I have found the perfect half-face respirator in the 3M 7500 series. It's comfortable to wear and keeps my lungs save. Most importantly, it's a respirator I don't dread wearing. It'll get used more often than my previous model. If you don't use your respirator regularly, I am confident the 7500 series will get you thinking differently about what a respirator can be. Not to mention, the Wood Whisperer likes the 3M 7500 series too.