Use of neurotoxic materials in theatrical production
by Rebecca M. Burton, CIH, MPH
Published March 2019
Theatre artists use a lot of weird stuff. Moreover, we use a lot of weird stuff in ways it was not designed to be used. We mix things, like alkyd based paint with water-based elastomeric, to make intentionally curdled paint. We might take a heat gun to a textured surface to get it to bubble and crack. We might need to glue gravel made out of bead foam to a wearable backdrop with flexible adhesive (i). But the thing is, when we use all these myriad chemicals in exciting and creative ways, we’re opening ourselves up to some pretty significant exposures, if we don’t take care. One of the primary hazards of our common materials is that of neurotoxicity.
Simply speaking, a neurotoxin is a chemical or chemical compound that alters the structure or function of the central nervous system. However, right off the bat I have to start with a disclaimer, because English is a complicated language and scientists have a Thing about being semantic. In the medical / toxicological / biochemical fields, the word toxin is reserved for harmful chemicals that are biological in nature, like snake or spider venom, and toxicant is used for things that are not, like lead, or solvents. Most people outside those fields are not aware of this distinction (or at least don’t observe it), so the results you’ll find if you do an internet search for “toxin” will be divided based on whether their source is from the academic scientific community. For purposes of simplicity I’ll be referring to “neurotoxins” in this article as any chemical acting injuriously upon the central or peripheral nervous system. Most of the harmful chemicals we use in arts production aren’t biological in nature, anyway(ii).
So how do neurotoxins work? Well, to answer that we need to go back to the basic entry level biology classes you may (or may not—BFAs, amirite?) have had in college or high school. Remember that all the various systems in the body do their thing based on signals from the brain that prompt organs to work in certain ways, and different substances (like hormones) to be produced, increased, or decreased in order to maintain or correct the body’s equilibrium, and keep it running optimally. There are, scientifically speaking, a bajillion ways these systems can get mucked up (™).
Very briefly, most chemical muck-ups work by interfering with the chemical structure of some body-produced chemical, and either prevent it from performing the reaction necessary for health, or cause it to perform the reaction to excess, and then further effects proceed from this initial error in a ripple-like way. The body chemicals in question are usually proteins like amino acids, peptides, enzymes, and a whole host of others. The nervous system also relies particularly heavily on electrical impulses occurring at the right times and in the right ways, so if the proteins that regulate these impulses get mucked up, the electrical impulses misfire, and the effects can spread throughout the entire system [1].
The nervous system itself is made up of two basic divisions: the central nervous system (CNS), and the peripheral nervous system (PNS). The CNS is the brain and spinal cord, and the PNS includes all the other nervous system tissue anywhere else. The PNS includes all the nerves that carry information between the CNS and other parts of the body, and the CNS processes that information in the brain and spine and decides what to do with it [2]. The nervous system is particularly vulnerable to chemicals that can pass through the blood-brain barrier, which is basically a special kind of cells and capillaries lined up in a very particular way, which prevents most blood-borne molecules from reaching the brain. Molecules that can cross this barrier tend either to be very small, nonpolar, and highly lipid (fat) soluble, or else have a very special kind of structure that allows them to mimic things that are designed to pass the barrier, almost like special agents in disguise [1].
In general, in arts production you’re going to be running into mostly two main categories of neurotoxins: metals and solvents (iii). Metals show up in pigments, welding fume, soldering fume, and sometimes in your production environment, like flaking lead-based paint or contaminated soil. Solvents show up when you’re using solvents—either for thinning non-water-based paint, for cleaning, for special treatments like spattering bead foam with acetone, in adhesives, and on the beer porch after (hopefully) your work call is over. (Yes, ethanol is a neurotoxin.) I’m not saying there aren’t any other exposures, but in my experience most of them are going to fall into these two groups.
Solvents
A solvent is a liquid organic chemical used to dissolve a solid material. While most solvents are derived from petroleum or other synthetic materials, some are naturally derived (iv),like turpentine and citrus oil. Some common solvents you may encounter in your production spaces include: acetone, citrus cleaner, paint thinner, and denatured alcohol(v). There are other solvents you’ll mostly run into as part of adhesives (glues, cements, etc.): more acetone, heptane, hexane, cyclohexane, and toluene. This is the type of solvent you’ll find in rubber cement, barge cement, and other contact adhesives. They also come out of vehicle exhaust from incompletely-combusted gasoline—which you may run into if you use powered industrial vehicles inside or spend a lot of time on the loading dock.
Any of these solvents can affect the nervous system. For the most part, exposure will be through inhalation of the rapidly evaporating liquid, but some can be absorbed through the skin. You’ll notice exposure through symptoms such as dizziness, drowsiness, fatigue, irritability, and nausea. As exposure increases, these can progress to unconsciousness or death. Long-term exposure to lower levels can cause permanent nervous system damage resulting in mental illnesses, memory loss, insomnia, and in extreme cases, a disease similar to multiple sclerosis [2].
Metals
Metals and metal-mineral compounds are the other main class of neurotoxins you’re likely to encounter in theatre. Some of the most potent include lead, mercury, antimony, arsenic, cobalt, copper, lithium, manganese, and some forms of nickel. Some have various levels of toxicity depending on the route of exposure—whether you inhale them through mixing a powder that becomes airborne or through welding, absorb them through the skin when you dunk your hand in a mixed paint, or ingest them when you eat while your body or clothes are contaminated [3].
I’m going to dedicate a special paragraph here to lead. Lead is simultaneously one of the most dangerous substances a human can be exposed to, and also one of the most ubiquitous. In acute exposure concentrations, it can cause mental retardation, coma, convulsions, and death. In low level chronic concentrations, it can irreversibly lower a person’s IQ, cause behavioral disorders, negatively impact attention span, and low educational attainment—and these are just the health effects to the nervous system. It is present, in varying amounts, in the air, the soil, in foods, and in water. Plenty of art materials still contain lead, and there is no safe measurable level of lead in the body. Government regulations for the use of lead by businesses are getting stricter and more costly, but many small companies and individuals operate outside the law and fly under regulators’ radar [4-7]. It can contaminate your clothes, your car, your home, and your heating/cooling system, so you take it home and share it with your family and pets. You should do everything you can to avoid lead-containing materials and processes. Be aware of the potential for lead in your environment if you’re operating in an old and rundown space, or recycling a lot of old props or scenery(vi).
This brings me to controls. What can we do about exposure to neurotoxins in our work? The first thing is to require a safety data sheet for every material you use (for things like truck exhaust that you’re exposed to without “using” it, check out an SDS for “gasoline”). Every. Single. One. If you don’t have a safety data sheet for it, don’t use it. Once you have the SDS, read it and understand it. A telltale hazard statement for neurotoxicity you’ll see is “may cause drowsiness or dizziness.” You might also see “may cause damage to organs,” or “may cause target organ effects” and then as a footnote see the organs listed as being central or peripheral nervous system. These hazard statements will be paired with the exploding chest pictogram which indicates health hazards. Sometimes the toxicology section of the SDS will show a chart telling you which ingredients of a mixture are associated with which health effects. Otherwise, you can look them up in a database like Gestis.
Heirarchy of Controls
Once you know you’re dealing with a neurotoxin, go through the hierarchy of controls: Elimination, substitution, engineering controls, administrative controls, and finally personal protective equipment.
Elimination: Can you just get rid of it? Do you really need to sculpt your foam by spattering it with acetone? Can you carve it instead? Can you sew that trim onto the costume or prop instead of gluing it?
Substitution: Can you substitute something less toxic for the material containing the neurotoxin? Can you use denatured alcohol to wipe down your greasy steel stock instead of acetone? Monona Rossol provides a really nice chart of solvents showing the various types and their relative toxicities that I highly recommend [2].
Engineering controls: You’ve determined you have to use the neurotoxic material, so now how can we protect you from its effects? Can you use ventilation to blow it away from you? Can you use it within a glove box that will keep you isolated from it? Can you brush your paint instead of spraying it? If you’re thinking about a dry pigment, can you purchase it in a liquid solution instead? This will help to keep it from becoming airborne.
Administrative controls: You still need to use the thing, you’ve explored all your options for engineering it away, now you need to limit the damage it can cause. Administer training, so that your staff knows the hazards of the material. Teach them ways to use it that will limit exposure. Limit the amount of time any one person will be exposed to it to avoid overcoming the body’s natural elimination process. Have a serious housekeeping policy to keep the material from contaminating your work environment and clean it up right, every time.
Personal protective equipment (PPE): Generally used in conjunction with administrative controls, PPE forms the last barrier between the employee and the hazardous material. PPE is not an awesome solution for exposure because there are too many ways for it to fail. Did the employee use it right? Is it still in good condition? Is it the right kind? Do you have the appropriate glove material for the substance? Are you wearing safety glasses? Should you be using chemical goggles or a face shield? What about a smock or apron? Is a respirator appropriate for this job?
Let’s talk about those respirators. Respirators can be a handy method of controlling exposure to certain airborne contaminants under certain conditions. But they have definite limitations and require a number of precautions to make sure they are being used effectively. These can be found in the OSHA respiratory protection standard, and they are put in place to make sure the protection you think you are getting is the same as what you are actually getting. Briefly, when using a respirator, you need to do some homework to determine:
- Respirator type – protection factor, material, etc.
- Cartridges and filters – type, protection factor, reusability
- Cleanliness and storage
- Employee medical clearance needs
- Training needs
- How to convince your employees with facial hair to shave it until they’re done with respirators
Respirators are really not the magic protective barrier they sometimes get credit for being. I wish as much as anyone we could have some really good Harry Potter-worthy protective charms, but the science just isn’t there yet.
All in all, there are a lot of ways we can hurt ourselves in theatre, and use of neurotoxic materials is just one of them. But like most health hazards, with careful planning and research they can usually be used safely to achieve the desired effect, and if they can’t, the danger isn’t worth it.
References
1. Stine, K.E. and T.M. Brown, Neurotoxicology, in Principles of Toxicology. 2015, CRC Press, Taylor & Francis Group: Boca Raton, FL. p. 189-223.
2 . Rossol, M., The Artist’s Complete Health and Safety Guide. Third ed. 2001, New York, New York: Allworth Press.
3 . Rossol, M., The Health and Safety Guide for Film, TV, and Theater. Second ed. 2011, New York, NY: Allworth Press.
4 . Aizer, A. and J. Currie Lead and Juvenile Delinquency: New evidence from linked birth, school, and juvenile detention records. NBER Working Paper Series, 2017. DOI: 10.3386/w23392.
5 . Billings, S.B. and K.T. Schnepel, Life after lead: Effects of early interventions for children exposed to lead. American Journal of Economics, 2017.
6 . Liu, J., et al., Blood lead concentrations and children’s behavioral and emotional problems: A cohort study. JAMA Pediatrics, 2014. 168(8): p. 737-745.
7 . World Health Organization. Lead Poisoning and Health. WHO Newsroom Fact Sheets, 2018.
Footnotes
(i) A real thing I did. #wall #pyramus&thisbe
(ii) Unless you count mold spores. Or the snake that lived in my paint shop in Delaware.
(iii)“Naturally derived” does not mean harmless. Mother Nature makes plenty of very harmful things. Just ask anyone who’s ever been bitten by a brown recluse, or this artist.
(iv) Any of these materials I’m discussing may have additional hazardous properties besides neurotoxicity, but to avoid coming out of this with an article less lengthy than Encyclopedia Britannica, I’m only discussing neurotoxicity in this piece.
(iv) Not an exhaustive list.
(vi) I don’t know if they ever used lead paint on costumes, but it sounds plausible.
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