The Toxicology of Modelling

By Frank Mitchell

This article was first published on the Hyperscale website in August 2002. We feel it is such an important topic that we received permission from the author to reproduce it here. See the feedback at the end of the article for addendum notes sent in by interested readers.

By Frank Mitchell, D.O., M.P.H.
IPMS - USA #789

Toxicology: The study of the adverse effects of chemical agents on biologic systems.

Introduction | Respirators | Safety Glasses | Plastics | Adhesives | Paint | Miscellaneous | Summary | Feedback

Introduction

In modelling, we use a lot of what are often termed hazardous materials. While the potential for harmful effects from these substances is real, there is also a lot of information floating around out there that is not accurate or is very out of date. In this presentation, I will try to correct some of that while providing information you can use to protect yourself and your family.

Respirators

Dust Mask

Air-Purifying Respirator

Safety Glasses

If you wear glasses, make sure that the lenses are impact-resistant plastic. If you do not, then buy a pair of safety glasses from your hardware store and use them whenever you are doing something involving power tools or some material that could splash. The glasses are very inexpensive and could save your sight.

Plastics

Styrene

Vinyl

Adhesives

"White" Glues

Solvent Adhesives

Always better to use the solvents in small amounts; limits the possible health effects, and also serves to decrease the number of parts that can be melted. I keep an old decal solution bottle on the bench and fill it from the larger container.

These solvents are rapidly metabolized and eliminated by the body, and they do not accumulate over time; thus no long-term effects would be expected to occur. Although the potential carcinogenic effects of these solvents have been widely studied, there is no reason to be concerned if used as most modelers would employ them. There is NO evidence whatever that MEK or toluene, for example, causes cancer in humans.

Cyanoacrylate Adhesives ("superglues", CA)

Handling Cyanoacrylates

Keep a supply of waxed paper handy; put a drop on a small piece of the waxed paper and then apply the glue with the eye of a needle or even a piece of wire that is stuck into the eraser of an ordinary pencil. This system allows only a small amount of the glue to be exposed. The CA on the waxed paper will polymerize only very slowly so that it will remain useable for rather long period of time. This technique works well with either the thin or the thicker gap filling forms of the adhesive. A side benefit of this method is that it makes for neater models because it allows for very precise placement of the glue and there is less chance of glue going where you do not want it.

In summary, the cyanoacrylate adhesives are, in my view, among the most useful materials in our tool boxes, but they are also, by far, the most dangerous. Care must be exercised, or what is supposed to be a hobby can produce unwanted and very serious adverse health effects.

Epoxy Compounds

Sanding cured resin produces particles which, for the most part are too large to move into the lower parts of the respiratory tract (trachea or lungs). These are termed "nuisance dust". However, a mask should always be used when sanding these materials, particularly when using power tools which can produce much smaller particles. They are usually cleared within a short period of time, but it is obviously better not to have them there in the first place. A simple and inexpensive paper mask is sufficient, but should be replaced frequently (maybe every 2-3 hours of use) as the moisture from your breath eventually gets it wet. Always wet sand if possible.

As with most other modeling materials, the bottom line with epoxies is to use them in as small quantities as necessary for the project. If large amounts are required, then a better respirator and hand protection (gloves) are in order.

Paint

The Basics

It must be apparent by now that paint formulation is a very variable thing; the small bottles of paint we use and take for granted contain a very sophisticated product, a product that, regardless of what it may be called, is capable of producing adverse health effects unless some common sense precautions are employed.

When sprayed, the droplet/particles size of the paint becomes small enough to be respirable; protection can include an air-purifying respirator (NOT a dust mask), a paint booth, or some other way of assuring that the amount of inspired paint and paint components is minimized.

There are several designs of small paint booths available. If the booth is not operating correctly, the paint exposure to the modeler can actually be much worse than it would be if no booth were used because the paint is hitting the sides and back of the booth and returning directly into the painter's breathing zone.

When Using a Paint Booth

Filters must be cleaned on a regular basis and any fans connected to the booth need to be checked for correct operation. Make sure that the exhaust is located so that the emissions are not being re-introduced through a nearby window or door. Even without a booth, there are techniques you can use to lessen the amount of paint emissions.

Miscellaneous

Future Floor Polish

Sharp Edges

Knifes, saws, razor blades, etc. are designed to cut, and they don't care what they cut. A little care can prevent accidents. As one example, put some clay on the handle of the knife so that it can't roll around.

Power Tools

Wood

A paper mask provides protection, and can also give comfort if you are annoyed by wood dust. Remember when using cyanoacrylates on wood that it can bubble and send small droplets a considerable distance, and the fume even further.

Soldering

Setting Solutions

Decal setting solutions generally contain acetic acid or alcohol. They should not be of concern.

Summary

As hobbies go, modelling is not one that most people would consider dangerous. However, there are potential problems that can arise if the materials that we use are not treated with some respect. For the most part, what is needed is some common sense and caution in the way we do things. Where chemicals are concerned, whether in the workplace, at home, or in our hobbies, familiarity definitely breeds some contempt. Therefore, it really takes a little mental effort to remember that these materials can cause problems; don't let those problems happen to you.

© Copyright 2002 by Frank Mitchell

Feedback

In October 2006 Mike Sloan sent us additional information:

I was reading the section on modelling safety, in particular the section dealing with respirators. I would like to add a couple of points to this:

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This article was published on Saturday, April 12 2014; Last modified on Saturday, April 12 2014