It's getting to be the time of year when young goblins rule the streets, but some everyday items may include more trick than treat. While officials this fall are on the lookout for stores stocking candy laced with the harmful chemical melamine, yard-sale shoppers might be wise to be wary of plastic sippy cups, regardless of festive pumpkin decor. Here's why, along with a short outline of the plastics controversy in recent months.

Last Friday, attorneys general from New Jersey, Delaware and Connecticut wrote manufacturers requesting that they refrain from using a certain plastic, bisphenol A (BPA), in baby bottles and formula containers, reported the Associated Press. Aside from citing concern about BPA's risk to infants, the attorneys general referenced a preliminary study in a September Journal of the American Medical Association article linking high BPA levels in adults to heart disease and diabetes.

In contrast, the U.S. Food and Drug Administration declared in August and again in September that adults and babies face no threat from plastic products with BPA. About 93% of adults tested in a national CDC survey showed traces of BPA in their urine.Despite the FDA's stance, another U.S. government body, the National Toxicology Program (NTP), reported in September "some concern" about fetuses', infants' and children's exposure to BPA, according to USA Today. "Some concern" falls in the middle of a five-point ranking of adverse effects considered by the NTP, which has no regulatory power. While in April it rated BPA of "some concern" for accelerating girls' puberty, by September the NTP downgraded this risk to a "minimal concern," and found only "minimal" or "negligible concern" about BPA in adults.

Meanwhile, a few retailers intend to voluntarily strip their stores of baby bottles embedded with BPA, Canada plans to prohibit them, and some consumers may proactively seek alternatives.

A September article in Natural Solutions, "A Clear and Plastic Danger," reviewed years of research, by scientists like neurobiologist Frederick S. vom Saal, suggesting that endocrine disruption in humans could be triggered by intake of BPA -- created as a synthetic estrogen and now tapped to make plastics look clear -- as well as phthalates.

Used in polyvinyl chloride plastics for pliability, phtalates are banned by the European Union for the composition of toys. "Once inside us, endocrine disrupters interfere with normal hormonal processes," author Alan Reder wrote. BPA is detected in, and leaches from, "the linings of canned foods and soft drinks, including canned infant formula; clear plastic baby bottles and sippy cups; refillable water bottles; food storage containers; and dental sealants [and] composite dental fillings."

Natural Solutions' advice: Don't drink from or keep food in plastic-ware made of BPA or phthalates; avoid heating such plastic in the dishwasher or microwave; reduce consumption of canned foods; check the ingredients in toys and cosmetics.

Expect more studies -- and news, as bills to ban plastics and class actions make their way through U.S. legislatures and courts. For advanced reading, check out The Plastic World, the October special section of Environmental Research, edited in part by vom Saal.