Plastic waste has become a major area of investment and concern for beauty brands over the past few years, with multiple companies testing out more sustainable packaging options and initiatives. Earlier this year, Procter & Gamble-owned hair care brand Herbal Essences joined forces with waste management giant TerraCycle to launch a series of bottles comprising 25% beach plastic, while Kiehl's Since 1851 unveiled a limited-edition version of its signature ‘Rare Earth' mask in April alongside John Legend, presented in new, lower-plastic packaging. REN Clean Skincare has pledged to become completely "zero waste" by the year 2021, and personal care conglomerate Unilever recently unveiled a three-part plan to target plastic use in the US, including a pledge for 50% of its plastic packaging to be made from post-consumer recycled (PCR) content by the end of 2019.