Microwaving Polymer clay is a new process and some people might not accept the new method of curing the clay. They will rather follow the manufacturer's baking instructions, DO NOT MICROWAVE, for fear of venturing into the unknown.

" Fear of danger is ten thousand times more terrifying than danger itself " - DANIAL DEFOE

I don't blame them, as there are so many warnings about using microwave oven, Danger of Coffee or Tea Explosion, putting a metal spoon in the superheated water can burst out of the ceramic mug and scald you. Warning about Exploding Egg after Microwaving in the oven. The facts are out there and it's causing concern to too many people, but one must observe the manufacturer rules when using the microwave oven.

Testing theWarnings using a proper container, I set the control dial to high, heat up the water for 5 min. I took out the container and put into the boiling water a metal fork, there was no reaction in the container. I reapeated another test, by putting a tea bag in the container, there was also no reaction or any water explosion. The problem of the Warning in the internet is the used of ceramic cups instead of a microwaveable container. The ceramic cup can be over heated causing the situation. Anyway, do not use vessels other than Microwaveable Container and Dinnerware.

Another problem with microwaving is phthalate plasticizers, which is in the polymer clay. The manufacturer indicated on their site that "as recently as last year, a CPSC Chronic Hazard Advisory Panel concluded that DINP, a phthalate, presented "an extremely low or non-existent" risk to reproductive and developmental processes in humans due to DINP exposure." The level of phthalate plasticizers was a controversy as claimed by VPIRG "research indicates that adults and children using polymer clays may be exposed to phthalates at harmful levels"

Even though there's controversy on phthalate plasticizers in polymer clay, I am confident that the manufacturer of the product are responsible organization, they will not create harm to adults and kids all over the world using their products. Twenty one years of addiction to the polymer clay have given me lots of fun in playing with the clay. I am in good condition with my health, except when you are getting older, you are not getting stronger.

If the "Chronic Hazard Advisory Panel concluded that DINP, a phthalate, presented "an extremely low or non-existent" risk to reproductive and developmental processes in humans due to DINP exposure." even there is leaching of plasticizer in the water after microwaving the low or non existant amount will not to create harm to adults and kids.

There are also lots of other research about plasticizer and here are some of them:

ICTI Responses to Greenpeace's Claims Against the Use of Polyvinyl Chloride (PVC) Against in Toys

" Phthalate esters are used more widely than any other class of plasticizer, and no other class of plasticizer has ever been subjected to the same degree of safety and toxicity testing.

The evidence about the plasticizer most frequently cited as hazardous by Greenpeace, diisononyl phthalate (DINP), is unequivocal:

* it has a low order of acute toxicity

* it is not a skin irritant

* it does not represent a reproductive or developmental concern for humans and in vivo tests for estrogenic effect on the endocrine system are consistently negative at realistic exposure levels.

The fact is, that after half a century of vinyl's use in toys, there is no evidence that the presence of phthalate plasticizers has harmed a single child. Vinyl has proven itself to be a safe material that makes clean, affordable and fun toys for children around the world."

Koop panel report concludes phthalate plasticizers are safe - independent peer review panel headed by former Surgeon General C. Everett Koop

Paper, Film, & Foil Converter,  August, 1999  by Sheila A. Millar

"The report strongly reinforces the need to be sure that regulatory decisions are made based on sound science in a manner that realistically assesses the likely exposure potential of adults and children.

Recently, the controversy over the possible health hazards of di(2-ethylhexyl) phthalate, commonly known as DEHP, and diisononyl phthalate (DINP), both used as plasticizers in flexible vinyl products, led to the creation of an independent peer review Panel by the American Council on Science and Health (ACSH).

Chaired by former Surgeon General C. Everett Koop, the Panel released its risk assessment report on June 22, concluding that the scientific data indicated that DEHP and DINP were not harmful."

Update, Jan. '99:
Lead, Cadmium, Phthalates still found in Children's Products

Understanding Phthalates - basic facts "Phthalate Toxicity
The CPSC and the Dutch government, in laboratory simulations of children's sucking and chewing behavior, have recently concluded that although children using PVC teethers would indeed swallow significant amounts of Phthalates, these amounts are too small on a daily basis to present a hazard. "  

Baking Instructions from Manufacturer

Going back to the Baking Instructions, Polyform is right to set the instructions, but they did not elaborate the situation. I conduct the test, directly microwaving the clay in the oven, using a plaster base (conduct lesser heat). Setting the control to high, timed it to 3 min. with a 6 mm. diameter bead. Observing the process, after, 2 min. the bead expanded, within 3 min. it started to fume and finally blacken, the smell was nauseating. The test was done under a control environment, in a well ventilated room with ceiling fan.


The Second test( below), using a 12 mm. diameter bead direct microwaving for 3 min. on a ceramic tile, after 3min. the bead was partially burned, even though there is insulation, touching the ceramic with a kitchen glove, the tile was really hot.


Under the above direct microwaving process, the fifty percent burned clay bead is also fully cured. Comparing microwaving the beads in a container filled with water, direct microwaving will difinitely burned the bead by microwave for 3 min. to 5min. depending on the bead size. To take advantage of a fast curing method, there is also a direct microwaving method to cure the bead which I will elaborate on it much later.

Comparing direct microwaving and water microwaving, the latter is much safer as the bead will not burn, as long as there is water in the microwave safe container. Prolong microwaving the clay from 15min. to 30 min. will makes the clay bead even harder.

Microwaving process is limited to small miniatures or beads, you have to put your clay work in a container with limited space. It is not a method to replace baking in the convection oven, it is to help those people who don't own a convection oven. This is certainly a much better method, than using a hair dryer, boiling in water, bake under the hot sun, in the trunk/boot of your car. You can also cure the beads or miniatures in the microwave oven and bake them in the convection oven.



How To Use Microwave Oven To Harden Polymer Clay

Microwaving And Polishing Polymer Clay Beads

Microwaving The Multi-Polymer Clay Beads

Comparison Test: Microwaving And Baking Sculpey Premo

20 Minutes: Microwaving To All Types Of Polymer Clay

Microwaved Polymer Clay Beads And Miniature Bears After 1 year

Finally, A Microwaveable Clay


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