Polymer Clay Safety
by Tommie Howell
I preface my remarks by saying that I am not against safety per se. Taking prudent precautions in all areas of life is a good enough thing. As far back as the great Greek philosophers we are taught about the Golden Mean. However, encasing oneself in a bubble that hampers one's actual living or making statements that become so much alarmist rhetoric is just goofy.
I keep thinking this horse has got to be dead, but I'll be danged if people don't just go on beating it. The fact that I am revising and republishing this article some 5 years later is evidence of that fact. This poor horse has a name. That name is "The hazards of Polymer Clay." When reading this debate, one who is unschooled in the history and use of Polymer Clay would probably rank Polymer Clay right up there with dioxin, nuclear waste, and rat poison. I have read posts and e-mails from people just starting with Polymer Clay who have been about ready to take the stuff back to the store. To hopefully allay some fears I am going to examine some realities here. Before going any further let me clarify, I do not speak for people who have specific reactions to the clay; I know there are some. I am speaking in terms of the general populace.
TESTING ART MATERIALS
All of the widely available Polymer Clays have been tested from stem to stern by the Arts & Crafts Materials Institute (ACMI). This Boston-based organization does not take this testing lightly nor do they balk at rejecting materials that don't make muster. Polymer Clay has been found, by ACMI, to have the status of non-toxic, and as such, bears the ACMI seal of approval.
Now please indulge me here, this is going to get a little heady. I have done a lot of research for this article; some of the information that I have found is quite wordy. I believe, however, that if we take the time to digest it, we will be better off for the information.
In the early 1980s, the manufacturers of artists and crafts materials began to voluntarily submit their products to the ACMI for testing. A group of manufacturers, artist's organizations, and health professionals worked to put together the standards by which the submitted products would be judged. That standard is ASTM D-4236. Detractors would have you believe that ACMI is made up solely of manufacturers of art and craft materials. This is not true. It consists of all of the groups mentioned above.
If you look on your packet of clay you will see a notification that the Polymer Clay conforms to the ASTM D-4236 standard. Any product with this label is certified to be "properly labeled in a program of toxicological evaluation by a medical expert." A toxicological review board then reviews the findings of the medical expert. After all this is done, only then can a material bear the label that it conforms to this standard. This means that a medical expert who specializes in the bioavailability of toxins has evaluated the clay for health dangers, then that testing is further tested by a group of professionals who specialize in toxicology. So each product that passes has been effectively double evaluated.
The ASTM D-4236 standard is meant for art materials for adults. There has been a standard for children in effect since the late 1930's! A product that has been tested under the children's standard will bear one of two titles. "CP" indicates a certified product has undergone the testing process and is awaiting final approval. "AP" indicates the product has undergone the test and been approved for use by children.
So what does this "AP" status (which you can see on your packet of Polymer Clay) mean in a practical sense? It means that Polymer Clay has been "certified by an authority on toxicology associated with a leading university to contain no materials in sufficient quantities to be toxic or injurious to the body, even if ingested." (Emphasis mine) This is important to note: The authorities here are independent of the organization seeking certification. The papers that started all the fear of Polymer Clay rely on studies conducted by their own researchers.
In the early 1980s, The Public Interest Research Group (PIRG) decided to take a look at these standards. Since the labeling was voluntary, people were still using materials that could be unsafe. PIRG worked with the Center for Safety in the Arts and many legislators to get some laws passed that would require materials used in schools to be certified as non-toxic. California passed the first such law in 1984 and was followed by six other states in the mid 1980s.
All of this activity led to the 1988 Labeling of Hazardous Art Materials Act. This act was backed by PIRG, the American Association of School Administrators, the American Association of Pediatrics, the American Health Association, Artists Equity, The Center for Safety in the Arts, the NEA, the PTA, manufacturers of art products, dealers, and artists themselves.
The law went into effect on November 18, 1990. It was then and now mandatory under federal law that an artist material must bear a hazard label if it is not certified as non-toxic! They define an artist material as "any substance marketed or represented by the producer or repackager as suitable for use in any phase of the creation of any work of visual or graphic art of any medium." (Sounds to me like Polymer Clay fits in there.) Beyond this, even materials some artists use that are not considered an "artist material" must still be labeled by the Occupational Safety and Health Administration.
Now here is where we get down to some nitty gritty. In the fall of 1992, the Consumer Product Safety Commission (CPSC) came up with their final statement on labeling requirements. The ASTM D-4236 standard was modified as follows:
A substance is a hazard if it is a known or probable human carcinogen, and has a cancer risk of one in one million or more, or is a known or probable neurotoxic or reproductive or developmental toxicant, and if exposure is above a certain defined level (Allowable Daily Intake).
This modification takes into account such things as:
If there is an upper limit on how much contact one can have with a material, it must be stated in a warning label. Polymer Clay would be required by federal law to carry such a warning if it was toxic in any of these ways. In fact, Polymer Clay is forced to bear no warnings of any kind!
- Chronic health effects in adults and children
- Which chemicals have the potential to cause adverse health effects such as cancer and reproductive maladies
- How much can be absorbed into the body or bioavailability
- Acceptable daily intake levels
Who else has good things to say about Polymer Clay? Ever hear of Consumer Reports Magazine? In their research, they found no adverse effects due to Polymer Clay even in reports of people and pets that had eaten it. Almost all Polymer Clay artists can point to a time that they, their children, or their pets ingested some amount of Polymer Clay with no ill effects.
Now let me move on to some specific concerns. Many people are concerned about the "fumes" from baking clay. The normal baking of clay may produce some smell, I find that smell pleasant but others do not. The only fumes that are produced come from burning the clay. Even these fumes, while quite nasty to smell, have no chronic effect.
The people at Fimo tell us that burning clay releases hydrochloride gas. This gas can irritate the mucus membranes and cause stinging of the eyes, nose, and throat. The response to burning clay they recommend, and what a prudent person would do, is to turn off the oven and vacate the area until the gas dissipates.
You stand more risk from your Teflon cooking pans than from burning Polymer Clay.
What about those pesky phthalates? People say "Okay, Okay! You win on the clay itself but those plasticizers will be the end of us all!" Long ago in a less cautious time, dioctyl phthalate (DOP) was used in the plasticizers. This use has been banned and DOP is NOT used in the making of Polymer Clay.
The concern over this particular phthalate is what causes all the uproar. Think of it like Red Dye #2. They have red M&M candies again, because other red dyes were used that don't have the harmful effect that RD#2 had. The phthalates used in Polymer Clay today are monitored under all of the hazardous materials testing that I presented earlier. Remember, if it contained known human carcinogens, Polymer Clay would be required by federal law to bear a warning label. Again, Polymer Clay is not required to bear such a warning.
A Duke University study from 2000 states in it's summary:
In summary, phthalate esters found in these Polymer Clays offer little or no acute toxicity concerns and are not a chronic hazard concern even assuming a large (24 mg) daily ingestion of these clays. Analyses of these clays for residual vinyl chloride found non-detectable (<1 ppm) levels. The clay matrix does not break down to release hydrogen chloride gas until temperatures of 350o F. or greater are reached, with progressive release at higher temperatures: curing at temperatures low enough to prevent destruction and blackening of the clay body will prevent appreciable hydrogen gas release. Little phthalate ester is released during curing, even when heated to the point that the clay breaks down: there is little opportunity for incidental food contact.
CURING IN THE OVEN
Many are concerned about baking in their home ovens. One of the beautiful things about Polymer Clay is that it is a material that can be brought to permanence without the expense of a kiln or other additional firing device. This is a drawing point for many people; otherwise they would work with earth clay for sculptures and glass for making beads and millefiori.
The only reason you would need a separate oven, let alone put the dang thing outside, is if you don't like the smell of the baking Polymer Clay. If you clean your oven on a routine basis, you have no worries from cooking your dinner in the same oven that you baked your clay in earlier that day.
FOOD AND POLYMER CLAY
If Polymer Clay is non-toxic, why then, you might ask, can't you put food in a Polymer Clay bowl? Well, let me tell you it has a lot more to do with the food than the clay. The inert baked clay is not going to poison you. Polymer Clay is not a food grade plastic mainly because it is very porous. You cannot clean it well enough to insure no little bugs are going to grow in leftover food.
People naturally assume that a material that is not food grade is somehow dangerous. This is not always the case. While there are some materials -- some pottery, for example, contains lead in the earth clay -- that are in fact dangerous in and of themselves, Polymer Clay is not one of them. Polymer Clay's story is that it simply doesn't sanitize well.
It has been suggested that the scares over Polymer Clay toxicity have grown due to the duplicity of early Polymer Clay artists who thought, "If we scare people off, there will be less competition." Then those scares grow and get passed around innocently by people who are genuinely concerned.
No one can say if this allegation is true or not. I would say that it is a possibility. If you feel the need to take a lot of precautions in order to feel safe, I will not tell you that you shouldn't.
I would ask, however, that you not go around like chicken little crying that the sky is falling, because it scares talented new people from picking up the clay. We lose new blood over this sort of thing.
Use your common sense when you work with clay. Don't make a meal of it, but don't freak if your miniature poodle happens to chomp on some. And if you screw up and use a knife that you cut clay with to butter your toast one morning, you don't have to call poison control.
The very last thing I have to say on this topic will perhaps be the most vehement. There is a statement that I have seen in various forms over the past few years. It is a question that just chaps my butt: "Would you want to find out (10,15,20) years from now that you gave (yourself, your family, your pet) some kind of (cancer, disease, demon possession) from Polymer Clay?"
To be honest with you, I want to say, "Oh, hell yeah! I want to give them bubonic plague, Ebola, and the heartbreak of psoriasis as well!"
This question is a classic case of what Aristotelian logic calls the fallacy of hyperbole. When there are no facts to back up an argument, the only thing left to do is state your case in the most outrageous and frightening way you possibly can.
So basically, I contend that the most dangerous thing about Polymer Clay is trying to use a wavy blade without cutting the hell out yourself.
Thank you, Tommie. You can visit Tommie's
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