Here's the run-down on plastics, according to the Oct. '05 issue of Mothering Magazine, evidentally taken from The Green Guide (www.thegreenguide.com).
"Look at the recycling number stamped on the bottom of the container: 2, 4, and 5 are OK for food storage. Avoid 1, 3, 6, and 7.
#2 High-density polyethylene (HDPE) is the durable, opaque plastic that milk jugs are made of. It's considered safe, even for multiple use, and is accepted by most curbside recycling programs. However, few reusable #2 containers are available.
#4 Low-density polyethylene (LDPE), like the related HDPE, is a food-safe plastic used to make plastic wraps and plastic bags. It is a good choice for food storage.
#5 Polypropylene (PP) is readily available in reusable containers such as clear deli tubs. It has not been shown to leach harmful chemicals, but is not as widely accepted for recycling as other plastics.
plastics to avoid
#1 Polyethylene terephthalate (PET or PETE), used for most clear disposable bottles, is safe for single use. But studies indicate that after repeated use, PET containers can leach DEHP, an endocrine-disrupting phthalate and probable human carcinogen.
#3 Polyvinyl chloride (V or PVC) is an inherently hard substance that is softened by the addition of phthalates and other additives. Once softened, PVC is used in a variety of consumer products, such as toys, backpacks, shower curtains, and plastic wrap. There is some evidence that the phthalates in PVC can migrate into food, especially if the food is fatty or hot. Phthalates are endocrine disruptors that can cause cancer in laboratory animals and may be linked to asthma in people. In addition, the manufacture and incineration of PVC releases dioxin, a known human carcinogen, into the environment. To minimize exposure to PVC, unwrap cheeses and other plastic-wrapped grocery items, cut off a thin slice of the food where it was in contact with the plastic, and store the rest in a safer continer, such as a glass gar, waxed paper, or a #4 plastic bag. Make sure to purchase only non-PVC plastic wrap.
#6 Polystyrene (PS) can leach styrene, a possible human carcinogen that may also interfere with hormones. Although usually encountered as Styrofoam, polystyrene also comes in nonfoam forms, such as clear takeout containers and plastic cutlery.
#7 Other. This usually means polycarbonate, a hard, clear plastic used to make baby bottles, water pitchers, and Nalgene-brand water bottles. Polycarbonate contains bisphenol-A, an endocrine disruptor that can leach into food or water.
Even the safest plastics can potentially leach chemicals when exposed to heat from microwave ovens, the dishwasher, hot food, or direct sun. Promptly recycle any containers that are scratched, stained, or misshapen."
If you're in search of glass storage containers, Ikea sells them. They have rubber gaskets around the glass lid and it makes a nice fit into the glass bottom.