Urgent warning over blue lagoon which is like a 'bath full of bleach' The dangerous lagoon has sparked warnings this week - and it is all down to its high alkaline pH levels that make it similar to swimming in a 'bath of bleach'. 11:54, 3 JUN 2021 Updated Latest news email updates straight to your inboxInvalid EmailSomething went wrong, please try again later. Subscribe When you subscribe we will use the information you provide to send you these newsletters. Your information will be used in accordance with ourPrivacy Notice. Thank you for subscribingWe have more newslettersShow meSee ourprivacy notice Police have issued a warning to stay away from a blue lagoon that's like a 'bath full of bleach' and have implored locals and day trippers to stay away.