By THÉRÈSE MARGOLIS

So we know that the sun’s rays are dangerous, causing not only premature aging, but potentially even skin cancer.

And we have all been read the riot act about the horrors of tanning beds, which can be 10 times more potent than the UV rays emitted by the midday sun.

But what about those self-tanning lotions that keep popping up on beauty counters across the country?

Can we safely give our skin a golden bronze glow without risking life and limb from ultraviolet radiation?

Derma-oncologist Rossana Janina Llergo Valdez doesn’t think so.

Llergo Valdez, who, in addition to her private practice, is vice president of the Mexican Foundation for Dermatology (FMD), insists that although self-tanning lotions and creams are much safer than unprotected exposure to sunlight and tanning beds, there are still some serious concerns regarding the safety of these do-it-yourself tanning products.

While modern sunless tanners have come a long way since those early formulas that left skin orange and streaky, they still use chemicals to create a temporary illusion of brown pigmentation in the skin’s outer levels.

Regardless of the brand (and there are a plethora of beauty companies offering their own lines of sunless tanners), the main active ingredient in these lotions, creams, mousses and oils is dihydroxyacetone (DHA), a substance that reacts with the amino acids in your outer skin to give a tanned appearance.

But Llergo Valdez says that DHA can cause skin irritation or allergies and has even, in some instances, been linked to skin cancer.

“We don’t really know what the long-term effects of using DHA might be,” she said during a recent conference of skincare organized by the FMD.

“And while DHA has been approved for external use, it should never be inhaled, ingested or exposed to areas covered by mucous membranes, including the lips, nose and areas in and around the eyes, because of the potential risks it poses.”

Llergo Valdez also noted that many people think that because their skin is colored by the DHA, they are protected from the sun’s rays the same way as those who have natural tans produced by increased melanin, which acts to shield the skin to some degree from UVA and UVB rays.

“Most sunless tanning lotions do not contain sunscreens,” she warned.

“Despite giving you a tanned appearance, sunless tanners don’t give you a base tan that reduces your chances of sunburn.”

Consequently, Llergo Valdez said, it is important to use sunscreen no matter how dark your skin may appear as a result of a sunless tanner.

Your best bet, Llergo Valdez said, is to avoid indoor tanning lotions altogether, wearing protective clothing and plenty broad-spectrum sunscreen reapplied every few hours whenever you are outdoors, and especially when at the beach.

“Porcelain skin is healthy skin,” she said.

“Learn to love the skin you were born with and protect it from the elements, both natural and manmade. A dark tan may give the false impression of a healthy glow, but deep down, it is anything but healthy.”