Is Resin Toxic?

[John F Smith]

Hi folks,

 

There is a lot of misinformation and misleading statements about the resin we use in aftermarket parts.

 

So, let me address the question directly; I have spent hours searching the internet on this topic and reading the Materials Safety Data Sheets from the various (and numerous) manufacturers, and they all have one common theme.  Resin dust is NOT toxic.

 

That's not to say that it can't be harmful, and I'll get to that in a minute.  Probably the biggest misconception is that it's carcinogenic.  The fact is that the International Association for Cancer Research has definitively stated that it is NOT carcinogenic.

 

So, what's wrong with the stuff.  Well, like any other powdered substance, if you get it in your eyes, it will irritate them (no surprise there!).   And, if you get it on your skin, you may be one of the rare people who has an allergic reaction to it.  Note, please, that I did NOT say that you can develop an allergy to it, you may just have something like a skin rash which is termed as "an allergic reaction".

 

And, if you breathe in just about any powdered substance (including dirt), it can irritate your lungs.  Not because it's toxic, but because your lungs don't like to have that kind of stuff in them.  That's just as true of styrene dust as it is for resin dust.

 

So, what precautions should we take.  Well, you probably shouldn't sand it without wearing a mask.  You don't need a NIOSH rated vapor mask, but a simple particulate mask will do, much like the ones that they sell for people who are spray painting their homes.  Wearing your glasses, or eye protection if you don't yet need glasses is a good way to keep the stuff out of your eyes.  And, like any other thing that we use in this hobby, good ventilation is important.

 

I hope I have helped to put to rest some misconceptions about resin dust.  It certainly is not my intent to be a "troll" here or to start a big argument or controversy.  If you disagree with what I have said, please include the source of your data so that I can get educated about it, too.

 

Best to everyone, and Happy Modeling,

 

John

Edited April 11, 2014 by John F Smith

[BradG]

Well said. People also need to realise that your lungs clean themselves so if you do happen to breathe in some resin dust it won't build up, the mucus produced will carry it out and you'll either expel it or just swallow it.

[LSP_Matt]

Interesting and sounds commonsense. 

 

Thanks.

 

I like wet sanding.  Often faster as the abrasive remains clear of crud

 

Matty

[Out2gtcha]

Agreed. I dont wear a mask like I know I should, but like Matt, I like wet sanding. Not just resin, but styrene as well. It seems to naturally clean the sanding abrasive, as well as keeping the dust in check.

[Jeff Herne]

I don't wear a mask, and one time after sanding the pour blocks on an Aires gear bay set, I coughed up a 1/32 ejection seat.... 

 

Seriously though, thank you doctor!

[Bill Cross]

It should be pointed out, however, that CA glue fumes are NOT non-toxic, and should be used with a ventilator or other means of dissipating them.

[Harold]

I don't wear a mask, and one time after sanding the pour blocks on an Aires gear bay set, I coughed up a 1/32 ejection seat.... 

 

Seriously though, thank you doctor!

I know if they ever have to autopsy me, they will find a bunch of lost parts and a enough resin to build several complete models.

Edited April 11, 2014 by Harold

[John F Smith]

Thanks, everyone, for your responses on this topic.  I hope we can clear up some misconceptions about modeling with resin.

 

Bill, I would tend to agree with you about CA fumes, although I have read conflicting analyses in the MSDS sheets about it.  Some classify it as non-toxic, but irritating, others as toxic and irritating.  Where they all agree, and I agree with you completely is that the stuff should only be used with adequate ventilation.  Thanks for pointing that out.

 

John

[wunwinglow]

Also, getting solidified resin hot by drilling, sanding etc, especially with a power tool, can have the resin decomposing. I'm at home right now so will have to wait til I go back to work to look up our safety handling notes, but Personal experience tells me that the smell, and sudden streaming eyes and nose means something unpleasant is in the air at that time! Wether it is or is not carcinogenic is not the issue; i don 't want to breathe it in under any circumstances!!

 

Tim

[Guest Peterpools]

John

Thanks for the information on resin dust. I still like to sand it outside just because of the mess unless I'm wet sanding. Just an old warhorse and except for the recent present, never wore a mask when air brushing and back in the day no one ever thought about a paint booth.

Peter

[John F Smith]

Certainly didn't mean to offend anyone's sensibilities with my post about using resin in our hobby.

 

I was merely trying to point out that the stuff isn't intrinsically poisonous and to describe what I think are "common sense" precautions that we should all be using in this hobby whether we are working with resin, styrene, or Tamiya Extra Thin Cement (which smells suspiciously like MEK to me).

 

Jennings, you are absolutely right, I should not have used that "D" word in my post.  I agree with you completely that almost nothing in health is definitive, and I was remiss in using it.  As to the organization, I got it's name wrong in my post.  It's proper name is The International Agency for Research on Cancer (IARC) which is the specialized cancer agency of the World Health Organization.  It's mission and functions are really quite interesting and described in some detail at www.iarc.fr/en/  (available in French or English).

 

Tim, I wouldn't want to heat the stuff up and get the fumes in my eyes or nose, either.  That's why I don't use power tools of any kind with it, including rotary tools like Dremel.  And, as I mentioned in my post, I always ensure I have adequate ventilation.

 

I certainly do appreciate that both of you mentioned obvious hazards which I either didn't mention or wasn't very clear about, and added to our knowledge of something that many of us use increasingly in our hobby.

 

Best Regards,

John

[LSP_Matt]

Be *very* careful with taking statements like that to the bank.  I'm not arguing that resin dust is going to cause you lung cancer next week, but to make a blanket statement that it has been "definitively" stated not to be carcinogenic implies a great deal of clinical research has been done in order to come to that conclusion.  I would doubt very much that *any* clinical medical research has been done on inhaling resin dust (there's no money in it).  To make a "definitive" statement requires definitive proof, and unless this organization (which I've never heard of in any medical literature I've ever read, which is quite a lot) comes up with this definitive proof, I'd put about $.000002 worth of faith in it.

The bottom line is, powdered resin doesn't belong in your body, period.  Will it kill you next week? Probably not.  But they said that about cigarettes and coal dust for a long time too.  Any kind of substance like that in your lung epithelial tissue *can* cause irritation, which over the long term *can* cause carcinogenesis, even if the substance itself isn't "poison".  Asbestos is a prime example.  Asbestos isn't "poison".  It causes its damage by constantly irritating the epithelium of the lung tissue, leading to cancer.  

 

There are very, very (very, very) few things in medicine that are "definitive".  The two words I am always careful never to use in my practice are "never" and "always".

 

J (RN, BSN, CCRN)

It's probably not worth overly intellectualising the argument much Jennings.  It's an interesting excercise but only if you have a depth of knowledge to begin with.  It's not that one quibbles over nuances but rather, the public health message has a potential to be lost and pre-existing irrationality perpetuated. 

 

Standard precautions of PPE remain a good primary defence when using anything potentially harmful.  Risk minimisation is always a good choice...even if it is labelled nuisance dust.  Occupational rather than hobbyist levels of exposure to any risk are also important to include in any appreciation as well as any individual characteristics that predispose to illness.

 

When one weighs cause of most acute hospitalisations though, it'd never stop anyone making hobby kits.  If it did you'd be overly worried about so much you'd have a shorter life from just ...worry.

 

Matty

[Jeff Herne]

Anyone wanna see the ejection seat I coughed up? It's for a 1/32 MiG-25, what are the odds of that? 

 

In all seriousness, I've had so many medical issues since this car accident that I think something definitive would be a good change of pace for me personally...lol.

 

J

[fmitche]

This is an article I wrote several years ago to answers some questions about this topic. I have supported my plastic obsession by practicing Occupational and Environmental medicine which involves lots of safety issues. If you have any questions, drop me a line---

Frank

 

The Toxicology of Modelling

. 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

The simple paper mask found in any hardware store.

Very effective against particles (dust) of the sort generated by sanding wood, "resin dust", etc.

Totally ineffective against chemical fumes, such as superglue reactions, solvents in paints, etc.

Become ineffective after several hours continuous use due to moisture from the breath, and should therefore be replaced on a frequent basis.

Air-Purifying Respirator

Uses replaceable canisters that are typically mounted on a half-face mask generally made of rubber.

Does not cover the eyes.

May have one large canister, or two smaller ones; both equally effective.

Canisters should be changed periodically; for modeling purposes, probably every couple of months is sufficient.

Use canisters labeled for organic vapor.

Perhaps the most important thing about respirators in modeling is remembering to wear them. It is very easy to think that a job will take only a minute, so why bother to get the thing out? Wrong Thinking.

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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.

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Plastics

 

Styrene

Generally polystyrene, a polymer of liquid styrene.

Innocuous; some "nuisance" dust is produced by sanding, but particles are generally too large to be taken into the lower respiratory tract (the trachea and lungs); machine-sanding can produce smaller sizes.

In general, about only possibility for toxicological harm is burning; fumes can be irritating.

 

Vinyl

Often used for aftermarket and home molding of canopies and other clear parts.

Essentially non-toxic.

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Adhesives

 

"White" Glues

Originally produced from animal parts (you don't want to know).

Today, are primarily water soluble emulsions of polyvinyl acetate; may also contain small amounts of other components to speed drying, produce different colors, etc.

Essentially non-toxic.

Solvent Adhesives

Most are methylene dichloride, ethylene dichloride, methyl ethyl ketone, toluene, or similar compounds; they work by dissolving styrene plastic and therefore weld the parts together.

Widely used in industry for many purposes.

Acute toxicologic effects generally due to inhalation; first symptoms arise from involvement of the central nervous system and are similar to alcohol ingestion.

May be absorbed through the skin and cause de-fatting (drying); cracks and rash can occur; with quantities typically used in modeling, these effects are generally not seen.

In the eye, liberal washing (several minutes at least), should suffice.

If more than a small drop, see a physician, but eye toxicity not high.

Commercial tube and liquid cements may also contain some solvents; also often have thickeners, retarders and other substances added to slow drying and to discourage glue sniffing.

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)

Originally developed during World War II; widely marketed in the late 1950's.

Used extensively in industry and in medicine for repairing small holes in the eye and in binding metal replacements (such as hip joints) to the surrounding bone.

Cyanoacrylates have many uses in modeling, and in many formulations (very thin liquid, gap-filling, gel).

Cyanoacrylates can cause mechanical or chemical effects.

Mechanical:

Do not "dry"; they polymerize (or cure) instantly, but this slows as the glue ages.

Accelerators supply base (opposite of acid); therefore, due to the slightly basic nature of the skin, they work very well for gluing fingers or other body parts together.

Chemical:

Primary chemical effect of cyanoacrylates in modeling is airway and eye irritation which can be intense due to fume that is released during the curing process. Can also cause more severe effects including permanent eye damage and chemical asthma.

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.

 

Keep a can of acetone nearby; it is the best agent for removing CA from skin (or anywhere else).

DO NOT just pull stuck fingers apart. You will almost certainly pull off at least one layer of skin and severe injuries can result. Instead, apply the acetone liberally and work the fingers apart.

When used on wood, cyanoacrylates can fume very vigorously, so be especially careful when using it for this purpose. The eye and nasal irritation can be severe.

The possibility for extreme irritation does not end after the cyanoacrylates are cured. Cured cyanoacrylates can produce significant fume when sanded - especially when worked with a power tool.

If you should get cyanoacrylate adhesives into the eyes, do not waste time attempting to open them; immediately get to medical care. Cyanoacrylate in the eye is a true medical emergency and urgent care is mandatory.

 

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

Composed of a number of different resins, hardeners, diluents, etc., depending on the needs or products.

As adhesives, formulations may cure very quickly to very slowly.

Often used today for casting individual parts or entire kits. In this use, generally known by the generic term "resin".

Generally composed of two parts which are mixed together in specific amounts; once combined, exothermic (heat-releasing) chemical reactions cause the mixture to harden.

It is the component parts, rather than the cured material, that causes most of the problems related to epoxy compounds.

The components are known to be sensitizers, that is, they can sensitize the skin, lungs, and other organs so that subsequent exposures can cause an increased reaction; the response can occur after the first use, or after the hundredth.

Therefore, care should be used while mixing the parts together and until the substances have cured.

While many epoxies will say that they are cured in 15 minutes, etc., care should still be taken for a considerably longer period, even though they feel hardened.

When completely cured, essentially non-toxic in a chemical sense.

On the skin, epoxies can also cause a dermatitis, but that condition may or may not be related to sensitization.

Can also cause eye damage; any incidents should be seen by a physician as soon as possible. Most common way into the eye: rubbing with an uncured epoxy-coated finger.

 

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.

 

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Paint

 

The Basics

All paints are mixtures of a number of components.

They may include pigments, solvents (toluene, xylene, lacquer thinners, etc.) carriers, dryers, stabilizers, and whatever other components the manufacturer may choose to include.

Whether the paint is labeled a lacquer or enamel does not really matter; they differ chemically only in the proportions of the various components.

Acrylic paints are often considered to be non-toxic, BUT, the typical acrylic paint contains 2-6% solvents (generally glycols and glycol ethers), plasticizers, preservatives, and fungicides.

Some acrylic paints use water as a base while others use alcohol.

Alcohol is not as volatile as the other solvents, but can still produce some effects if the dose is high enough.

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

 

First and foremost, wear a proper canister respirator.

If possible, spray in front of a window that can be opened.

place an ordinary oscillating fan behind you. This will push the emissions away from your breathing zone and through the window.

Try to spray in a room that does not contain a cold air intake for the furnace/central air; if one is present, just cut a piece of cardboard that can be taped over the inlet when spraying.

Closing outlet vents can seem counterintuitive to keeping emissions from the rest of the home, but when the fan is not on, the emissions can move through them.

Close the door of the room while painting.

Keep the fan on, the window open, and the door closed for a period of time, say 30 minutes after spraying is complete.

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Miscellaneous

 

Future Floor Polish

One of the more useful products for modeling to appear in years.

A totally man-made mixture of several chemicals.

Essentially innocuous, but still should be used with some precaution since it was not designed for use in airbrushes and has never been tested for extreme exposures.

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

 

Extremely useful; I have three on my workbench and use them every day.

Always consider the use of a paper mask and eye protection.

Remember that the speed of the rotating bit will generate particles that are smaller and will travel further.

Most of the tools I have seen rotate so that they throw the particles directly at the user's breathing zone; thus, a dust mask can be very useful.

Be particularly careful when dealing with brass or other metals since they can generate small pieces that can produce eye damage.

Use caution when using thin cut-off disc to do work on thick or hard materials because the discs themselves can shatter and throw pieces some distance.I try not to watch the cut from an angle, not at the direct plane of the rotating disc; the odds would therefore be less that I would get something in the eye.

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

 

Solder may contain lead (although this has been phased out of most

Fluxes contain resins, binders, and other chemicals that allow the metal to bond.

All these things can produce fumes which are capable of causing short-term symptoms that are somewhat flu-like.

At the very least, all soldering should be done in a well-ventilated area.

Setting Solutions

 

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

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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

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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:

 

Air-purifying respirators must be properly fit-tested on the person wearing it. Most, if not all, canister respirators come in three sizes. If the respirator does not fit properly, it probably will be ineffective.

The proper filters for the application must be used. When wearing a respirator, the person's face must be clean shaven. Stubble or a beard will render the respirator ineffective.

Each time the wearer uses the respirator, he must ensure that it is properly sealed to the face and there are no air leaks. The respirator should be cleaned after every use and should be stored in a clean and dry place.

When airbrushing, a respirator may be the most important piece of equipment a modeller should have, next to a spray booth.

Toluene is a toxic chemical which with long term exposure may impact the body's soft tissue such as your kidneys and liver. It can also affect your white blood cell count and bone marrow. It is not a safe chemical to be exposed to. It is usually found in certain paints and thinners and if possible should be avoided.

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Y

[LSP_Kevin]

Thanks for posting your information Frank. I was pretty certain we had this published as an article somewhere on our website, but I can't find it. If it's lost or non-existent, can I seek your permission to post it?

 

Kev