Every potter/ceramics artist needs to understand how to minimize exposures to hazardous materials. There is an abundance of information available today on every chemical used in your studio (and your house and garage, for that matter). Several years ago, the Occupational Safety and Health Administration (OSHA) required manufacturers to prepare a Material Safety Data Sheet (MSDS) for each hazardous material they produce, and to provide them, upon request, to the consumers of those products.
How to Find an MSDS
In addition to the supply house from which you purchase the material, an excellent source of MSDSs is the Internet. Not only do you receive the information immediately, you have access to as many as you like. This can be particularly useful because, although OSHA requires that MSDSs be prepared and available, there is no mandate for the information to be presented in a uniform way, and manufacturers have a great deal of leeway regarding what information is included in the MSDS.
To find an MSDS on the Internet, I usually use the search engine Alta-Vista (http://www.altavista.digital.com), entering the name of the chemical and the initials MSDS; for example, “copper sulfate” & MSDS. It is best to place the chemical name in quotes; otherwise, Alta-Vista fi nds information on anything dealing with copper and sulfate. Use the ampersand, without any spaces between MSDS and the chemical name, or the list of MSDSs will not be limited to those for the desired chemical.
A great attribute of Alta-Vista is that you can refine the search by answering a series of “include/exclude” questions. You can also specify which language you would like to see the documents in; many of them can be translated into the language of your choice with a few simple keystrokes or mouse clicks.
Alternately, you can find information about most chemicals by referring to several reference books. One of the most recognized texts is Dangerous Properties of Hazardous Materials by Irving N. Sax; it has been around for decades and is frequently updated. Another widely used reference is the Merck Index; its content is somewhat similar to Sax’s text. Both are fairly technical and require a reasonable understanding of toxicology to be of much benefit.
How to Read an MSDS
Once you have an MSDS in hand, you need to be able to glean enough information from it to use the material safely. Begin by reading the entire MSDS to seek out health hazard data, plus advice on first aid and personal protective equipment. Typically, MSDSs are divided into several sections; however, because there is no requirement for them to be written in a uniform manner, the titles and information in these sections will vary. Because of this variability, it is not a bad idea to refer to several MSDSs on the same chemical.
The health hazards section should contain information about the symptoms associated with exposure to the chemical. Exposure symptoms for some chemicals may include skin rash, headache or dizziness; others may cause flulike symptoms and/or a metallic taste in your mouth. Frequently, this section will recommend the first-aid procedures to follow to alleviate symptoms.
Of course, it would be better to avoid experiencing any symptoms to begin with, so look for information regarding personal protective equipment (PPE). In the ceramics studio, the two most useful pieces of PPE are a respirator and gloves; however, neither is intended to replace common sense (i.e., not ingesting or inhaling the material).
Considering the types of materials commonly used in ceramics, “rubber” gloves of nearly any type (latex, butyl or nitrile) can provide adequate protection; however, the gauze-type masks, commonly available at hardware stores, simply will not provide adequate protection against the small particles. The type of respirator needed is one that has been rated as suitable for particulate and radio-nuclides. These come either as disposable units (ideally suited for those who would use this protection on rare occasions) or units that can be cleaned and reused with new filter cartridges. Either comes in a couple of different sizes. The disposable units are less than $10 each and the nondisposable ones are about $20, but replacement cartridges are only a couple of dollars per pair. Remember, though, that these respirators only provide protection if there is a good seal between your face and the edges of the mask. You will not get a suitable seal if you have a great deal of facial hair.
Where can you find PPE? You probably won’t have much luck looking in the Yellow Pages under PPE, but you should see a listing for Safety Equipment & Clothing. Some industrial suppliers and large hardware stores are also starting to carry these supplies.
How Careful Should I Be?
Once again, this is information that can be obtained from the MSDS. There may be information on the MSDS that says the LD50 (lethal dose that kills 50% of a sample population) or LDLO (lethal dose low) is such and such a number. This number is often derived from testing in the laboratory, so the number is typically associated with rabbits or mice (something other than humans). Because the physiology of the human species and the test species varies, a direct correlation is not possible. There are lots of very complicated ways to estimate the conversion from the test species to humans; it is probably more important to understand the relative risk than to attempt to determine the absolute risk. After all, even within our species, there is a range of tolerance and susceptibilities to different chemicals. Some people get poison ivy; others don’t. The table below should give you some general idea of what the numbers mean.
Let’s use a couple of examples to clarify this concept: barium carbonate and table salt. The MSDS for barium carbonate prepared by Chemical Products Corporation shows an LDLO oral human of 57 mg/kg. This is particularly helpful because it is for human exposure, and because an LDLO can be expected to be very conservative. The table shows that the probable lethal dose is between a teaspoon and an ounce if the material is ingested-a fairly large amount of any material to casually ingest.
Too much of anything is not good for you; salt has an LD50 of about 7.0 mg/kg. So, between a pint and quart of salt would need to be ingested to be fatal.
What is less well known is the synergistic effect of chemicals; that is, our response to a chemical in conjunction with another. What is also less known is the chronic (long term) effect of many chemical exposures. Some chemicals are known to accumulate in the tissues of our bodies; others are purged. There are so many variables to consider that it would be prudent to reduce exposure utilizing all the tools and techniques available.
Keeping the Studio Clean
Exposure hazards exist not only when you are mixing ingredients, but any time some residue may be present. After you glaze, are there drips on the floor, the shelves, your clothes? Frequent cleaning with water is needed to keep these potential sources of contaminants under control. Venting the area where hazardous materials are mixed and fired also helps reduce your exposure.
Tags: ceramics artist
, Every potter
, hazardous materials
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