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toxicity of polymer clays

updated thu 27 nov 03


Brian Mittelstaedt on wed 26 nov 03

A search in Google of "polymer clay health" gave a number of references. This was the
first and most interesting of those I found. It is published by Susanne Miller, Environmental Health Advocate, Vermont Public Interest Research Group, Inc.

I've included the executive summary below.

Executive Summary

Polymer clays are a form of modeling clay that have become popular in recent years among children, adolescents and adult craftspeople. They are inexpensive, come in a variety of colors, are soft at room temperature, can be molded by hand into small or large items, and can be baked in a conventional oven at low heat, resulting in a permanent hard object. Fimo and Sculpey are the most common brand names of polymer clays in the U.S., but other different product lines exist. Unfortunately, these clays contain polyvinyl chloride (PVC) mixed with phthalate (pronounced tha- late) plasticizers. While the phthalate plasticizers make the clay soft and workable, they are also associated with potential health risks. Phthalates as a class of chemicals have been implicated in birth defects, reproductive problems, nerve system damage and other negative health effects.

VPIRG’s research indicates that children and adults using polymer clays may be exposed to phthalates at harmful levels. Even when clays are prepared following proper package directions, children and adults can breathe or ingest high levels of phthalates. In addition to phthalate exposure the research indicates that when polymer clay is overheated enough or accidentally burned, the PVC will break down and release highly toxic hydrochloric acid gas.

The potential for exposure to phthalates from normal use of polymer clays is troubling given the popularity of the clays both at home and at schools, the inadequacy of consumer warnings about the effects of these chemicals, and the effects phthalates may have on children. Moreover, since the Federal Toxic Substances Control Act does not require pre-market testing for new industrial chemicals, and because it is difficult to restrict the use of existing chemicals in commercial products, exposure to phthalates is cause for concern. VPIRG recommends that consumers avoid using polymer clays and calls on the Consumer Products Safety Commission (CPSC) to recall or suspend sale of polymer clays until they are shown to be safe for use by children and pregnant women. If the products remain on the market – VPIRG calls on manufacturers to provide adequate warnings to consumers as to why they should avoid use of the products or take special precautions when using them. Finally, state Attorneys
General should investigate the claims by manufacturers that the clays are “non-toxic.”


As a father of three craft-minded children and a potter myself, I found the article disconcerting...

Brian Mittelstaedt

Lois Ruben Aronow on wed 26 nov 03

There was a response posted to that report by the ACMI (information
below) that was not included in the previous post. I think it's only
fair to post both sides. The link is, and the article is
reprinted below.

Even though the materials are considered "non-toxic", I would never
allow my children to put it in their mouths, just as I wouldn't allow
them to put crayons or dirty fingers in their mouths. Sculpey says
explicitly in their instructions not to let the clay touch eating
surfaces, not to use eating implements as tools, and to wash hands and
surfaces well after using the clay. They even recommend you use a
glazed tile or a cutting board as a work surface. =20

Like any other art material (or non-food material, for that matter)
one should be mindful about it's use, read the directions, wash your
hands, don't put it in your mouth - and don't forget to have a little
fun with it. =20


Polymer clays in the ACMI certification program were
re-evaluated in October 2000 and continue to receive ACMI=92s non-toxic
designation, said Deborah Fanning, Executive Vice President of The Art
& Creative Materials Institute, Inc. (ACMI). This re-evaluation took
place at the request of the polymer clay manufacturers because of
questions raised at that time about phthalates in toys. =20
ACMI members do use phthalates in polymer clays but these
phthalate esters do not present acute or chronic toxicity concerns.
ACMI=92s consulting toxicological team at Duke University Medical Center
(DUKE) has evaluated these polymer clays for acute and chronic hazards
by all potential routes of exposure and have found none. A DUKE study
revealed that you would need to overheat and destroy the clay product
in the oven-heating process to release hydrogen gas, and <0.1% of the
phthalate esters would be released with no breakdown of the polyvinyl
chloride. =20

Woodhall Stopford, M.D., principal toxicologist of the ACMI
Certification Program, stated that =93Phthalate 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. Dr. Stopford=92s risk assessment, as well as an
executive summary, are available on the DUKE website at Simply click on =93Recent Toxicological
Issues=94 on the home page and then polymerclays1.doc for the risk
assessment or polymerclaysummary.doc for the executive summary. The
Consumer Product Safety Commission (CPSC) has extensively tested
samples of polymer clay for safety concerns. They found that the
polymer clay tested did not contain any volatile organic compounds and
that no acid gases were released if the clay was baked to 163o C
(325o F). They found that hydrogen gas was released only if the clay
was heated to the point of turning black, 180o C (356o F). =20

Mrs. Fanning said that ACMI would welcome another review of the
issue by CPSC. As recently as last year, a CPSC Chronic Hazard
Advisory Panel concluded that DINP, a phthalate, presented =93an
extremely low or non-existent=94 risk to reproductive and developmental
processes in humans due to DINP exposure. And, she noted, the U.S.
=46ood and Drug Administration in an April 19, 2001 fact sheet stated,
=93FDA believes that at the present time there is no reason for
consumers to be alarmed at the use of cosmetics containing
phthalates,=94 although the agency continues to study the issue.
It is not possible on such short notice to address the specific
test results described in a USPIRG report issued today, but the
inhalation report is clearly not in accord with that conducted by Dr.
Stopford. Nor has there been time to address in detail the
inaccuracies in the report about ACMI=92s certification program and the
independent evaluation of health risks conducted by the consulting
toxicological team at DUKE.

No hazardous level of any ingredient is permitted in any art
material product evaluated as non-toxic in the ACMI program, whether a
children=92s or an adult=92s product. ACMI=92s toxicological team takes
into account the metabolism and size of a small child when evaluating
materials that will be used by children. Thus, even children can use
polymer clays that are evaluated as non-toxic in the ACMI program;
however, supervision in the oven-baking process is recommended for
very young children. Parents, educators and others are urged to read
the labels on polymer clays and other art products to better
understand which have been evaluated by ACMI and which are non-toxic.
Some art materials meant for adults may need special handling as
indicated in the safe-use instructions on the labels.

Since the enactment of the Federal Labeling of Hazardous Art
Materials Act in 1988, currently administered by CPSC, not one
ACMI-certified product has had to be recalled by its member companies.
Mrs. Fanning noted, =93We believe this is an extraordinary record of the
effectiveness of the ACMI=92s certification program in protecting
children and other consumers.=94

The Art & Creative Materials Institute, Inc. is an international
association, composed of a diverse and involved membership, and is
recognized as the leading authority on art and craft materials.
ACMI=92s members are art and craft material manufacturers, and currently
there are over 210 members. Since its inception, ACMI=92s certification
program has certified that products in the program are either
non-toxic or appropriately labeled with any cautionary language and
safe use instructions. Of the 60,000 art materials in the program,
100% of the children=92s products and 85% of those meant for the adult
artist are certified as non-toxic. This certification program has
received the endorsement of experts in the field of toxicology and is
one of the finest industry programs in existence. ACMI seeks to
create and maintain a positive environment for art and craft materials
usage; to promote safety in art and craft materials; and to serve as
an information and service resource on art and craft materials. Press
kits are available from ACMI.

Lois Ruben Aronow
Modern Porcelain and Tableware

The Tattoo is back!