1. Eyeliner
Eyeliner has been around for centuries and is popular with many women as a way to frame eyes and make them stand out. However, although in most cases eyeliner is no cause for concern, applying any product so close to your eyes can come with its risks. Not only are many eyeliners made up of chemicals which can cause irritation, but applying the product too close to the inner corners of your eyes can lead to blocked tear ducts. To keep your eyes healthy, use a natural kohl eyeliner, avoid applying too close to the tear ducts, and replace your eyeliner after three months.

2. Tight ponytails
You may not think about your health when considering how to wear your hair, but your hair-do not only affects how you look, it can also affect how you feel. Wearing your hair in a tight ponytail can strain the connective tissue in the scalp, leading to headaches as well as hair breakage and loss. Wearing your hair in a tight braid and wearing headbands can also have similar effects. If you feel a headache coming on, let your hair down to help ease the symptoms.

3. Hair dye
While ditching your hair dye may seem like a scary prospect, continuing to colour your hair could have even more frightening results. The chemical para-phenylenediamine (PPD) is thought to be behind up to 80 per cent of allergic reactions to hair dye. While most of these reactions are relatively minor, including blisters and skin sores, PPD has been linked to more serious conditions such as permanent hair loss and, in rare cases, even death – although this link has yet to be confirmed. As allergies to PPD can develop at any time, it is important to perform a patch test every time you colour your hair. It may also be worth swapping to safer chemical-free or wash-out dyes.

4. Hair straightening products
Many women opt for salon straightening treatments to help keep curly or unruly hair poker straight for months at a time. However, in 2011 the US Department of Labor's Occupational Safety and Health Administration (OSHA) issued a health warning over the risks of exposure to the carcinogen formaldehyde found even in straightening products listed as formaldehyde-free. Whilst salon workers who regularly use these products are at the most risk, it is still wise to avoid the dangerous chemical by manually straightening hair with blow-drying and straightening irons instead.

Mascara can harbour bacteria that is transferred into the product after each application and which can reproduce in the dark, warm environment of the mascara tube, potentially leading to eye infections. To help reduce the health risks associated with your mascara, make sure you store your mascara in a cool place and replace it after three months. Also, avoid applying your mascara in the car or on a journey as the motion can cause scratches to the eye during application which can also lead to infections.

6. Lipstick
Apparently the average woman eats four to nine pounds of lipstick in her lifetime. Given that a 2004 study revealed that up to 28 per cent of lipsticks contain chemicals that can cause cancer, this is a pretty scary statistic. A 2007 study by the Campaign for Safe Cosmetics also found that more than 50 per cent of lipstick brands tested contained lead. Look after your health by switching to natural, organic brands of lipstick, particularly if pregnant.

7. Fish pedicures
In the last few years, fish pedicures have soared in popularity across the world, with people flocking to doctor fish spas for help with psoriasis, eczema or simple pedicures in which the fish nibble away at dead skin to leave areas smooth and soft. However, just as quickly as popularity grew, health reports were issued over the perceived dangers of this treatment. Reports state that fish pedicures could spread viruses such as hepatitis. While the risk is thought to be low, it is advised that those who carry a blood-borne virus, have any open cuts, or who have recently waxed or shaved their legs should avoid getting this treatment.

8. Shared beauty products
It can be tempting to borrow your friend's lipstick when you've forgotten your own or to lend your best pal your mascara when she asks, however sharing your make-up can also mean sharing infections. It is impossible to tell by looking at someone if they have an infection as some viruses can be contagious even before they begin to show. Sharing lipstick could lead to catching cold sores, while eye make-up is the most risky and can lead to eye infections such as the extremely contagious conjunctivitis. If you must share make-up, minimise risk by wiping off the top layer before use.

9. Alpha and Beta Hydroxy Acids
You may not have heard of Alpha and Beta Hydroxy Acids (AHAs and BHAs) but they are commonly used in many beauty products, including anti-wrinkle and acne creams. Both AHAs and BHAs act as skin exfoliants, sloughing off dead skin cells. However, alongside potential side effects such as burning, swelling and skin irritation, the chemicals have a fairly dangerous side effect in that they drastically increase the risk of UV skin damage, therefore increasing risk of skin cancer. If you must use these products, make sure you use a high SPF daily to minimise risk of sun damage. However, exfoliating skin with natural skin scrubs may offer a gentler solution to applying acids.