Polymer clay is, generally speaking, not dangerous at all for ordinary use. There are a few basic safety rules you should keep in mind to avoid any problems: don't accidentally eat bits of the clay, be careful not to let the plasticizer in the clay get into food, and don't burn or scorch the clay during firing.

This isn't a good idea. It's difficult or impossible to remove all the clay particles from some utensils (such as the pasta machine), and the plasticizer in the clay may remain on or in surfaces, particularly porous ones such as plastic. To be safe, don't use utensils for food again once you've used them with clay. (You may even want to label your clay utensils to make sure no one accidentally uses them in the kitchen.)

Residual plasticizer can remain in the clay after firing, and this plasticizer might leach out into food that touches even the fired clay, so it may not be safe to use polymer clay on surfaces that will be in contact with food.

This shouldn't be a problem for pieces that don't touch food directly, such as napkin rings. If you want to use polymer clay for a serving dish, consider sandwiching your clay design between two pieces of glass - that way it can be seen without touching the food on the dish.

The clay is safe to touch, but you shouldn't ingest it, so you need to clean your hands thoroughly after you work with the clay and before you eat or cook. Polymer clay sneers at soap and water. You can keep a rough towel or a package of wet wipes near your workspace, to remove the worst of it when you want to switch between colors of clay. Using a small pumice stone with soap will help remove the clay from your hands; so will some hand creams and facial "scrubs".

Another effective cleanup method is to rub a little oil (cooking or mineral oil) onto your hands, then wash it off with ordinary dish soap. (Thanks to Cristy Anspach for this tip.)

The main thing to remember when firing the clay is not to let your oven temperature get too high. If the clay gets hotter than 300° Fahrenheit, it can burn, and burning PVC gives off toxic fumes.

To avoid any chance of burning the clay, get an oven thermometer and calibrate the oven you'll be using. It's common for home ovens to be 25 degrees off the temperature on the dial, and if your oven runs hot you may be firing the clay at too high a temperature. Fire in a well-ventilated room; open your kitchen windows, and if you have a stovetop fan, turn it on during firing. For an extra margin of safety, some clayworkers fire in a toaster oven or portable convection oven which is placed outside, on a deck or patio.

Polymer clay normally gives off a slight odor when firing; this is nothing to worry about and not a sign that the clay is burning. Burning clay smells acrid and may cause your eyes or throat to sting. If you do burn a batch of clay, turn off the oven, open windows and turn on fans, and leave the house for an hour or two to give the fumes time to clear.

Attention bird-lovers: Birds are reportedly extra-sensitive to fumes, so if you have a bird, it may be safer to put either bird or oven outside while you're firing.

The rules for safety while sanding or buffing clay are similar to the rules for sanding wood or other materials. If you're dry-sanding (instead of sanding under water) or drilling a clay piece, use a face mask to avoid inhaling the tiny clay particles coming off the sandpaper. You should also use a face mask when working with aluminum-based metallic powders, since these fly everywhere and can cause damage if they're breathed into your lungs.

Always, without exception, use eye protection when using any power tool with the clay, whether for drilling, buffing, or sanding. It's very easy for a bead you're buffing to get loose and go flying, possibly into your face. Even the tiny clay particles can get into your eye and cause injury. You can buy plastic safety goggles at any hardware store.

Sure, as long as the kids are old enough not to try eating the clay. Children too young to use an oven safely will require supervision during firing. Soft clays such as Sculpey are easier to handle and may be more satisfying for younger kids than the stiffer clays; try making marbled beads or simple canes.

The plasticizer in unfired clay can be harmful to wood finishes, and it eats into some kinds of plastic. If you need to set clay down on a table or a surface other than your work surface, wrap it in waxed paper first to keep it away from the finish. Fired clay is neutral and can be put anywhere.