Author: James "Bo" Lovell
Edition: Model Aviation - 2008/03
Page Numbers: 45,46,47,48,50
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WORKSHOP AIR POLLUTION

Avoid health risks and stench complaints

by James "Bo" Lovell

"A small portion of my lung is collapsed?" I could not believe I was repeating those words to my doctor. I do not even remember what I asked him after that. What I do remember is staring at the area of my lungs he was pointing to on the X-ray film.

The how and why of it were unknown, and I would spend several weeks trying to recover and discover what had caused this to happen.

I was going to title this article "Glue, Sand, Paint, Wheeze?" because that was the order of business in the room where I build my airplanes. In early February of 2007 I had to visit the doctor on more than one occasion because of a persistent cough and a continuous feeling of fatigue that I could not shake.

After a week's worth of antibiotics and a steroid dose pack, there was no change in my condition. The chest X-ray revealed inflammation in my lower left lung that caused a gathering of fluid, which collapsed a small portion of that lung.

With the obvious cause of the coughing and fatigue identified, I wanted to know why my lung had acted this way without my permission. During a follow-up visit with the doctor, one week later I had an idea of what might have caused my condition.

The idea came to me like those instant realizations you get about which food made you sick. I had been on a building spree for more than a month. Because February in Alabama is generally cold and wet, I was doing almost all my work inside. For weeks I had been cutting, sanding, and gluing everything you would need to put several scratch-built, electric-powered foam airplanes in the air.

When I told my doctor what I did with my spare time and the types of materials I worked with, I could immediately see how hard it was for him to restrain himself from smacking me on the side of the head. I think his exact words were, "Just the paint fumes alone would be enough to irritate your lungs if you've been doing this long enough." He suggested a room air filter, at minimum a paper mask to keep me from inhaling airborne particles, and a promise to thoroughly clean the room I worked in before resuming building activities.

At the time I could not begin to understand how serious the threat was or how simple the solutions could be. After lots of research and relating my story to others in the hobby, I learned many interesting facts and even some urban legends.

Most people I talked to pointed to the black dust from the carbon-fiber rods and spars I cut with power tools as the main source of my problems. I received many different opinions and warnings about carbon fiber; they ranged from "do not breathe it" to "it's worse than asbestos."

Almost everyone else blamed the cyanoacrylate glue or the paint for my pulmonary condition. I was told that the "smoke" from cyanoacrylate when it cures is cyanide gas. Others did not know what it was but were positive that it was highly toxic. Other modeling friends assured me that I had simply painted the inside of my lungs and that it would take the alveoli a while to return to normal.

Every person who related a story to me was basing it on personal experience and best safety practices. I appreciate every comment and suggestion. In this article I share the facts and solutions as I have experienced them. This is a tribute, in large part, to my family of aeromodelers and their sincere desire to help.

Carbon-Fiber Fact

This material contains no known chemicals that cause cancer. Being exposed to and inhaling the dust can cause a variety of breathing problems, including bronchitis, and could impair pulmonary function.

All information I could find regarding carbon fiber's properties, including the Material Safety Data Sheet (MSDS) about graphite (commonly called "carbon fiber"), suggests that occasionally cutting this material requires no respiratory protection provided it is done with exhaust ventilation (for example, in a chemical fume hood). That refers to an industrial level of carbon-fiber dust, but it should stand as good advice even though I would not classify the amount of carbon fiber I cut in my shop as "industrial."

A picture in the original article showed the amount of dust created from a carbon-fiber rod cut roughly halfway through with a handheld jigsaw.

Cyanoacrylate Fact

Fumes from this glue are not poisonous, but cyanoacrylate's distinctive odor is highly irritating to the eyes, nose, and lungs. The fact that moisture levels directly affect how quickly or slowly this glue polymerizes is what makes it irritating. That is also why the bottle has a label advising its use in an adequately ventilated area.

The scariest category I could find when searching for information about cyanoacrylate was "CA Poisoning." When I read that heading on an MSDS, I thought I had found the smoking gun regarding a dangerous chemical, but I was pleasantly surprised by the warning's contents. The MSDS categorized cyanoacrylate "poisoning" the way you might call a python wrapped around your body "python poisoning": it mainly refers to local effects like fingers glued together or eyelids accidentally adhered. There have been humorous warnings about glued eyelids, but serious systemic poisoning from routine hobby use is not supported.

A practical tip: if you're at a flying event that requires overnight supplies, store your cyanoacrylate bottle well away from any nasal sprays or other personal hygiene items. There was nearly an unusual emergency at a hospital in Americus, Georgia, during the 2007 Southeast Electric Flight Festival because of such a mix-up. Do not snort your model-airplane glue.

Forensic scientists and detectives even use cyanoacrylate fumes to develop latent fingerprints. They allow fumes to build in an enclosed area with the object inside; when they disperse the fumes and process the object, the odor is unpleasant but, in reported cases, without adverse effects.

Several modelers described severe allergic reactions to cyanoacrylate, but these occurred in people who had worked with it for long periods. Even people proven allergic typically did not develop a reaction simply by getting adhesive on their skin. Does this mean it is okay to sniff cyanoacrylate? Obviously not. The annoyances with the glue are mainly physical and irritating rather than systemically toxic in typical hobby exposures.

Wood Fact

Wood dust can be harmful. The American Conference of Governmental Industrial Hygienists classifies hardwood dust as a confirmed human carcinogen (Class 1A, May 1996).

Balsa wood has no known adverse chronic health concerns, although some people have allergies to balsa dust. Recommendations for working with any wood that produces dust include using a mask or respirator. In industrial applications, ventilation is recommended to reduce dust buildup and the risk of potentially explosive airborne dust clouds.

I have never sanded enough wood while building models to create anything resembling an airborne dust cloud, but better safe than sorry.

Shop-Pollution Solution

None of the components mentioned above (other than hardwood dust) were shown to cause permanent adverse effects to the lungs in ordinary hobby use, but combined exposure to several chemicals and particulates over time or in quick succession can provoke serious respiratory problems. I feel certain the combination of several chemicals and particulates caused my condition.

Given that, I took steps to correct it. A friend in the automotive-repair business gave me a large cardboard box that used to contain a car's front bumper cover. I measured the ends and found them close to the 20 x 20 size of a household air filter I bought. Heavy-duty duct tape sealed everything tightly.

I put the fan on the bottom with the air flowing into the box, knowing that heavier particles would settle and my filter would pull smaller particles inside. You might call the contraption a type of automatic vacuum.

After roughly a month I noticed larger particles coming back out of the fan and decided to check and replace the filter. What I found was both amazing and a little scary: tiny particles had gathered in a thick but loose layer on the inside of the filter. Heavier particles stayed inside the box and blew around when the fan operated. After cleaning the box, I had a large pile of grayish-white dust I was glad to be looking at rather than coughing up.

My box-fan/cardboard-box/household-air-filter was simple and cheap, and I have had no breathing problems since I installed it. When I am trapped indoors I still use a paper mask; those seem to help.

Whenever possible I sand, paint, or use chemicals outside. If I must use them inside, I turn on my fan and crack a window for fresh air. Common sense is the best guide. But even with common sense, I continue to be amazed. I recently reviewed the warning label on a can of water-based polyurethane—a product I assumed would be exceptionally safe because it was water based—and found warnings advising not to breathe its vapors.

The one-year anniversary of my breathing problem was still a few months away as I wrote this. Like many people, I had to experience the consequences of living like I was bulletproof before I realized that the laws of common sense and human health actually apply to me.

After my condition subsided, I realized how fortunate I was to be able to continue building and flying model airplanes with no apparent lasting problems. I feel a responsibility to share this experience with fellow modelers and anyone else who cares to know.

I am not attempting to scare anyone away from the materials mentioned, nor am I pointing to any single solution as a cure-all. We are all different, with different tolerances and habits, so only you can decide what, if any, of this to use. The main point is to do your best to make sure you can continue to enjoy this hobby for as long as possible, even if you glue your fingers together from time to time.

—Bo Lovell [email protected]

Building the Shop Air Filter

Materials List:

  • One large cardboard box (mine was 6 feet tall; local body shops often have these).
  • One box fan. A rotary fan will work as long as you can seal the edges around its frame.
  • Two rolls of 2-inch-wide clear packaging tape or duct tape.
  • One central air filter (size up to you; a 20 x 20 x 1 is common).
  • Box cutter or other sharp instrument.
  • Sharpie or marker for drawing cut lines.

Assembly Steps

  1. Obtain a large cardboard box. Mine is 6 feet tall and was used to ship a front bumper cover for a new-model Volvo sedan. Local body shops will probably have many of these boxes.
  1. Gather the box fan, the central air filter, and the other items in the materials list.
  1. No matter what size central air filter you use (for example, 20 x 20 x 1), when you center the filter on the box and trace its outline for cutting, make the cutout 3/4 inch smaller on all sides. The air filter's cardboard frame takes up approximately that much room, and this will help you center the filter on the hole that will be cut. It also gives you something to push against when applying tape to seal the filter in place.
  1. Lay the box fan facedown on the bottom of your box and trace its outline. It is unnecessary to trace the bottom; you will be sliding part of the fan into the bottom of your cutout for the box fan. Make sure to leave the box-fan control knob and power cord outside the box.
  1. After marking and cutting the holes where your fan and filter will go, seal all edges and overlaps on the box to achieve as airtight a seal as you can. I sealed the outside corners and overlaps with tape, but you could seal from the inside if your box needs extra help. This also helps hold the box together for extended use.
  1. Use wide packaging tape or duct tape; you can stick half the width onto the box and the other half to the filter and the box fan for your initial seal. I recommend cutting several lengths of tape 3 or 4 inches longer than the surface you will be taping. That makes it easier to press down at the center to obtain a good seal between the cardboard and the fan and filter.
  1. Place the shop air filter unit where you want it. I situated mine with the fan on the bottom and the air filter above it. It could just as easily be put on its side and positioned under a workbench or other structure.

Even though a square or rectangular shape is not ideal for aerodynamic airflow, it tends to trap many larger particles in the box simply by allowing no air out except through the filter.

This filter is not intended to be the equivalent of a high-tech HEPA room air filter, nor will it remove fumes or odors from your shop. However, since I started using the filter while working in the shop, I have had no breathing problems during the colder months. The unit traps many small particles of wood, foam, and other materials that would otherwise be floating around my shop and in my lungs.

Medical Research Sources

Transcribed from original scans by AI. Minor OCR errors may remain.