When I was a kid, my mum and aunt always clipped their hair up before going in the pool. As women with curly and coily hair, they never let their locks touch the chlorinated water. I intrinsically understood that the water must be bad for curls, so for me and my much straighter hair, I dove in head-first without a care in the world.

But with age comes wisdom. The older I got, the more I realised just how ruined my hair was at the end of a summer season. Is it the pool? Is it the sun? Is it the ocean salt? Or perhaps a combination of all three?

As we close out the summer season, and many of us (including myself) are assessing whether our haircare needs to change with the seasons. With this in mind, it's important to understand exactly what happens when you put your hair in the water. I spoke to trichologist Chelcey Sallinger to ask everything about chlorine and salt water hair care. Her motto? "When it comes to hair damage, prevention is the key." 

Below, Sallinger shares how chlorine affects your hair, whether it does turn blonde hair green and when it's time to cut your losses – literally.

Does pool chlorine damage your hair? If so, how does this damage occur?

While swimming in the ocean or a pool can benefit your body and mind, saltwater, chlorine, and UV rays can damage your hair. Frequent exposure to these elements, especially during warmer months, can strip natural oils, fade colour, and cause split ends and breakage. Chlorine exposure can also disrupt the hair cuticle, leaving it dry, brittle, and highly porous.

Is it worse for certain types of hair? Does it really turn blonde hair green?

Chlorine damage is particularly harmful to curly hair, as it weakens the strands and diminishes shine. This can result in brassiness and unruly curls, coils, and waves.

Chlorine oxidizes the artificial colour, breaking down the colour molecules in hair. It's not chlorine by itself that turns blonde hair green in the pool, but rather the copper found in pool cleaning chemicals. Chlorine can cause hair colour to fade and lose its shine more quickly, especially in highly porous hair, such as those with bleached hair, which is more susceptible to losing moisture.

Is there any way to reverse the damage or colour changes after it’s happened?

The “sun bleaching” colour change experienced is oxidation and is irreversible. You can help to compensate for this damage with protein-based products that form “false bonds” within the hair. This is not a permanent solution, as the false bonds are eventually lost. But it can help your hair to feel better and be stronger in the short term.

At the end of summer, if you realise your hair is damaged, is there any way to bring it back? Or, is it time to head to the hairdresser for a cut?

Ultimately, the damage is done and it's time to “cut” your losses. When it comes to hair damage, prevention is the key.

What’s the best way to protect your hair before you get in the pool?

Rinse your hair with clean water before and after swimming. It’s as easy as jumping in a beach shower on your walk down to the water. By doing this your hair becomes less absorbent of the saltwater/chlorine and therefore minimises potential damage

Also, try a leave in treatment. Go one step further and protect your hair by applying a leave-in conditioner or hair oil. This will create a protective barrier that helps reduce chlorine or salt water’s ability to enter the hair shaft and prevents your hair from soaking up the water and its chemicals.

Is swimming in salt water better for your hair? Or can salt water cause damage too?

Although saltwater is gentler on your hair and skin than chlorine, due to being softer, it can still strip your hair of its colour, moisture and shine, and weaken its overall structure leading to increased frizz and dryness. Therefore, it's crucial to protect your hair using the same techniques, regardless of whether you're swimming in saltwater or chlorine.

What hair care regime would you recommend after a day in the sun at the beach or pool?

Shampoo. It is essential to wash your hair after you have been in the sun or water. The combination of hair product, dirt and sebum can lead to many unwanted scalp issues, impacting your hair from root to tip. Washing your hair and scalp regularly is also ideal for maintaining a healthy scalp, however, it’s important to use the right shampoo. I look for one with a pH of around 5.5, which matches the natural pH of your scalp and hair. This helps close the hair cuticle, resulting in smoother, shinier hair that is less prone to frizz and knots. Using a blonde shampoo for bleached hair will neutralise any brassy tones whilst simultaneously adding nourishing hydration back to your strands.

Try a Scalp Massager. It's a great way to treat your locks to a little TLC every few washes with a scalp massager to remove any product build up and help to stimulate blood flow.

Use a deep-conditioning treatment once a week when washing your hair to help restore the moisture lost whilst swimming. For those with bleached hair, look for formulas that offer strengthening properties to support the structure of weakened bleached strands.

Blow dry your hair – avoid keeping your hair wet for long periods of time as this is an environment where detrimental yeast and bacteria on the scalp can thrive, leading to scalp problems. Blow Drying your hair will also seal the hair cuticle, reducing frizz and enhancing shine. I recommend the Dyson Airstrait to my clients as it cuts down the styling time by 25 per cent without relying on extreme temperatures, preserving hair strength, reducing breakage and protecting hair’s natural shine.

What are your biggest hair no-nos post swim?

Avoid keeping your hair wet for longer periods of time.

Sitting around with wet hair is the perfect breeding ground for unfriendly yeast and bacteria on the scalp. I like to use the Dyson Supersonic Nural™ hair dryer to gently blow dry my hair and scalp after each post-swim wash or rinse. I find it also helps me beat the heat and humidity.

Hair is also a little more fragile when it is wet because two out of the three different types of chemical bonds within the hair are broken by water (salt bonds and hydrogen bonds), leaving only the disulphide bonds formed. So the sooner your hair is dry, the more resilient it will be and less susceptible to damage.

Also keep it simple and be gentle with hair care. You don’t need a million steps to have great hair and scalp health, just frequent hair washing and general good scalp hygiene. Avoid scrubbing at your scalp to overcompensate infrequent hair washing and be gentle when styling - brushing, drying and applying heat tools.