When parents pull a box of diapers off the shelf, how many of them are aware of the risks to which they are exposing their children: cancer, asthma, hormone disruption, and others. Dioxins, sodium polycrylate, dyes, fragrances, and phthalates are some of the ingredients credible scientific researchers have found in disposable diaper brands including Huggies and Pampers used by millions of parents. It's even been discovered that the dyes used to put decorations on diapers are known to cause diaper rash. Fortunately, there are much healthier alternatives.

Dioxins are a class of potent carcinogens (cancer causers) that are not made on purpose but are created as a byproduct of industrial processes like chlorine bleaching of paper pulp and some natural processes like volcano eruptions. The name dioxins refers to hundreds of chemicals, out of which about 30 are the most toxic. The most toxic, TCDD, was the contaminant in the infamous Agent Orange that made it so deadly. They are considered persistent pollutants because, once created, they hang around for a long time without breaking down and they stay in the human body for a long time, too.

Phthalates, on the other hand, are classed as endocrine disruptors. This means that they mimic human hormones and send false signals to the body.

A 1999 study tested emissions from three brands of diapers on mice and concluded, “some types of disposable diapers emit mixtures of chemicals that are toxic to the respiratory tract. Disposable diapers should be considered as one of the factors that might cause or exacerbate asthmatic conditions.”

The anatomy of a disposable diaper is pretty simple. There’s the inner layer touching your baby’s skin, the waterproof outer layer and the absorbent core in the middle. The diaper might have some fragrance, and dyes as well. When your baby does his or her business, the liquid is supposed to be trapped and distributed within the absorbent core.

The inner layer is often made from polypropylene (and maybe some aloe and vitamin E), the absorbent core from wood pulp and sodium polyacrylate.

The website BabyGearLab, which was founded by a pediatrician and mother, tested the absorbent cores of a number of diapers and reported that, “every one of the diapers we tested includes a matrix of fluff material and chemical crystals known as Super Absorbent Polymer (SAP) to soak up and trap fluid [more on this below]. The role of the fluff, usually made from wood pulp and may also include wheat/corn based materials, is to distribute the fluid, while the SAP is intended to absorb fluid and locks it in the core away from baby.”

Within that relatively simple structure, the most common chemicals causing alarm are dioxins, sodium polycrylate,, dyes, fragrances, and phthalates. The previously mentioned 1999 study also named other chemicals it found in diaper emissions, such as toluene, which depresses the central nervous system; ethylbenzene, a potential carcinogen; dipentene, a skin and eye irritant; and styrene, which harms the nervous and respiratory systems. Many of these chemicals are commonly used in manufacturing plastics and other industrial products, so it’s not too surprising to find them in a diaper with an outer liner made of plastic.

The easiest chemicals to skip are fragrances and dyes. Buy fragrance-free diapers that don’t have cute cartoon characters or teddy bears depicted on their outsides. In 2005, Pediatrics found that the dyes used on diapers were often the cause of diaper rash. Some dyes can even contain heavy metals — and heavy metals are not what you want near your baby’s skin.

Next up, dioxins. Nobody disagrees over whether or not dioxins are bad. They are bad. Period. Dioxins are such potent carcinogens that they are measured in the parts per trillion. In diapers, they come from chlorine used to bleach diaper material. Even chlorine-bleached diapers only emit trace amounts of dioxins, but why risk even that when chlorine-free diapers are available?

For a scientific look at the dioxin picture, check out a 2002 study that tested four brands of diapers and four brands of tampons. The study found dioxins in all samples, although in much lower concentrations than the amount of dioxin exposure from one’s diet. While some believe that the tiny size of dioxin exposure from diapers means it’s nothing to worry about, others feel it’s worth it to reduce dioxin exposure even by that little bit.

Phthalates are chemicals that make plastics more flexible. In diapers, they are most likely used on the waterproof outer liner. As Pediatrics notes, these chemicals are bad news for endocrine and reproductive systems. They found that “Phthalates are not chemically bound to these products and are therefore continuously released into the air or through leaching into liquids, leading to exposure through ingestion, dermal transfer, and inhalation. Children are uniquely vulnerable to phthalate exposures given their hand-to-mouth behaviors, floor play, and developing nervous and reproductive systems.”

Last up, sodium polyacrylate, also known as Super Absorbent Polymer (SAP). The jury is out on whether or not this chemical is actually harmful. In the 1980s, it was linked to Toxic Shock Syndrome (TSS) in tampons. However, this might be because it allowed women to keep tampons in for longer periods, creating a breeding ground for bacteria as a result.

While the link to TSS may be nothing to worry about, there are viewpoints on both sides about whether or not SAP is actually bad for your baby. One study linked superabsorbent diapers to urinary tract infections in girls. If you want to play it safe, go with cloth diapers. One site makes the point that — if nothing else — SAP might contribute to diaper rash by allowing you to change your baby’s diaper less frequently.

However, even some conscious parents out there do believe SAP is safe and continue using disposables that contain it. The brand gDiapers, which combines reusable diaper covers with disposable inserts that contain SAP, has a page explaining why they feel SAP is safe for babies.

Taking all of these criteria to mind — plus, of course, the additional criteria that a diaper must do its job as a diaper — BabyGearLab recommends three diapers based on its tests: Bambo Nature, Earth’s Best and Attitude. Other “conscious” brands include Honest Diapers, gDiapers, and — for an economical choice — Target’s Up & Up.

The winners tend to be fragrance- and dye-free, or use dyes that are free of heavy metals. They also eschew phthalates and chlorine bleach. However, they still contain SAP — you’ll probably have to switch to cloth if you want to avoid that.

Of course, yet another study — this one on the impact of diapers on walking — recommends allowing infants to go naked. While it has its obvious problems, it’s certainly one way to avoid any potential chemicals found in diapers.