Some yoga enthusiasts have a relationship to their mats that borders on friendship. In my own classes, I've heard people use adjectives like strong, safe, rejuvenated, replenished, and generous, to describe how they feel upon plopping down on their own rectangles of anti-slipperiness. But the truth about how most yoga mats are created isn't so glowing.

PVC (polyvinyl chloride), a hard plastic softened with plasticizers called phthalates, has been the most common material for modern yoga mats until recently. (Traditionally, cotton rugs were used.) Scientific studies have linked PVC or phthalates to a wide range of health problems, including cancer, kidney damage, lupus, allergies, and improper reproductive development and function. The E.U. just banned several phthalates in January, and in the U.S., the FDA cautioned against certain uses of medical supplies containing PVC. GreenPeace wants all PVC production to cease, because it releases dioxins into the environment. Moreover, even if phthalates turn out to be safe in low levels or certain uses, as the plastics industry hopes, PVC is not recyclable.

So my time on this earth is finite, but my mat's isn't? Fortunately, I found five nontoxic, next-generation yoga mats in contemporary colors that range from merely safer-to-make to fully biodegradable.

The hands-down grippiest eco-mat I found was the 3/16”-thick Harmony mat from Jade Yoga ($49.95)—with dripping wet hands, I held downward dog for twelve breaths without slipping. Cushioning was exceptional, and I used it straight out of the box, without pre-washing, unlike other models. The U.S.-made Harmony mat is 100% natural open-cell rubber with a mesh core to prevent tearing. It smells like a new bicycle tire, evoking happy memories (for me at least). Although it contains latex, Jade claims it usually won't cause a reaction in sensitive people. In midnight blue, the mat showed dusty footprints after one use, which wiped right off. Direct sunlight, heat and contact with oils degrade natural rubber and must be avoided, so don't use this one on an outdoor yoga retreat.

The Green Yoga Association advocates earth-consciousness in yoga practice and sells the EcoYoga Mat ($36-$45), made of 100% biodegradable jute and rubber and imported from Edinburgh. The manufacturer likewise claims that most latex allergy sufferers should be OK. Added jute fibers are exceptionally strong and sustainable, and the mat's top side looks like a woven rug dipped in rubber, which it is. Odd looks aside, the scruffy texture was pleasant and more resistant to my sweaty palms than PVC. The rubber underside was soft, nearly odorless and cushiony (I tested the 4mm model). My dusty footprints also stuck to the grape-colored “dark lavender” mat, but I hesitated to wet it from the faucet or my perspiration. However, the manufacturer recommends regular airing out and occasional soaking, followed by rolling with a towel, according to “the old traditional woolens method.” Same goes for sunlight and heat—verbotten.

If you like jute, but can't do latex, Gaiam offers the 1/8”-thick Envirofit Jute Yoga Mat ($40). This one's stylish enough to lay in your foyer, but beauty isn't everything—it's “eco-friendlier”—made of phthalate-free “PER plastic,” which is less toxic than PVC to produce, but not biodegradable (although jute is). It grips well in downward dog, but its real performance comes in standing warrior poses—my back foot remained planted. Gaiam also sells the double-thick, jute-free Premium Benefit Yoga Mat ($40). Made of PER, it could be mistaken for a conventional yoga mat. If you're latex-sensitive and like the feel of PVC, this might be for you.

The dark horse was the Earth Elements mat from Hugger Mugger ($42.95)—the company largely credited with popularizing sticky mats. Shrink-wrapped and stinking like modeling glue, I couldn't wash it fast enough, which is required. Amazingly, it retained no water or soap, dried quickly, and the odor disappeared in 24 hours. Made from a new substance called TPE, or Thermal Plastic Elastomer foam, this 5mm-thick bright purple mat is biodegradable, latex and PVC free, and produced non-toxically. It also matches the EcoYoga mat in the anti-slip department, with a textured surface and closed cell construction.

The yoga tenet of ahimsa instructs that we “do no harm,” planet Earth included. Since most eco-mat makers still make and sell non-eco models, the Green Yoga Association and Jade Yoga should be commended for selling only products that can return safely to the soil.

Harmony yoga mat from Jade Yoga

Cost: $49.95

Where to Buy it: Bean Products and other online retailers

EcoYoga mat from Green Yoga Association

Cost: $36-$45

Where to Buy it: GreenYoga.org

Envirofit Jute Yoga Mat

Cost: $40.00

Where to Buy it: Gaiam

Premium Benefit Yoga Mat

Cost: $40

Where to Buy it: Gaiam

Earth Elements Mat from Hugger Mugger

Cost: $42.95

Where to Buy it: Hugger Mugger

Photo: Jade Yoga