7 beauty trends that can kill you

We have an arsenal of beauty products we use to make ourselves look and feel gorgeous, but did you know that some of our favorite beauty items could contain ingredients that could do more harm than anything? Chemicals like formaldehyde and phthalates are just two of a slew of ingredients that be super dangerous and lead to irritation, infections, and even cancer. Ay, no!

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 Check out a list of some of the beauty hazards you might encounter so that when you're doing up those eyes, you also take a closer look at what exactly is in that bottle.

Image via Thinkstock

Formaldehyde

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Thinkstock

Products like keratin hair straighteners could contain high concentrations of formaldehyde, which could cause cancer after long-term exposure. That said, getting a keratin treatment every few months shouldn't be cause for concern, but opting for a good frizz-fighting conditioner and a flat iron would be a safer bet.

Costume Contacts

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Adam Ross/Flickr

Sure you'll get a crazy new look for just a few bucks, but are store-bought contacts worth an eye infection or vision loss? Let's go with no. Avoid grabbing a pair that doesn't require a prescription from a licensed professional.

Hydroquinone

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sunshinecity/Flickr

Some might use skin lighteners like hydroquinone to treat dark spots, but overuse could lead to skin discoloration. The chemical has also been linked to cancer in animals, but studies are still be conducted to see if this same link is applicable to human consumption.

Tanning

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whatsername/Flickr

A tanned body might look sexy, but only if the idea of developing skin cancer is attractive to you. Not only do tanning beds increase your risk for melanoma, but its UVA rays lead to wrinkly skin. Go for the spray-on tan or just rock your natural color.

Mani-Pedi Chemicals

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Quinn Dombrowski/Flickr

Mani-pedis are such a treat, but do you really know what's being sprayed, painted, and rubbed on your fingers when you go in for your beauty appointment? There's a reason why your manicurist wears a filtered mask. Not only are chemicals like formaldehyde, acetone, toluene, and phthalates present in the air just waiting to irritate your eyes, nose, and lungs, but an unclean salon could lead to some icky infections.

Latisse

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Michael Sandoval/Flickr

Who wouldn't want long and voluminous eye lashes without piling on layers of mascara? Well if you're using this prescription serum to get those lashes to grow beware: the drug could darken the skin around the eye or turn your iris brown. If you use eyelash extensions to give your peepers a flirty oomph, take note if the adhesives cause any irritations or allergic reactions.

Expired Makeup

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Molly/Flickr

No matter how much you loved that shade of lipstick, you really don't want to be applying old makeup onto your skin once bacteria has started to grow in it. Throw out foundation after one year, powdered makeup after two years, lipstick after a year of use, and mascara after three to four months.