Plastic microbeads are banned in wash-off cosmetics in many regions, but the ‘environmental’ alternatives are sometimes not much more sustainable. Now, a team of researchers has found that silica is one of the best.
Microbeads are manufactured plastic pellets, typically measuring less than 0.5 millimetres’ diameter. In many products they are designed to be washed off, where they pass through wastewater treatments plants and end up in marine ecosystems. This has led to them being banned in wash-off cosmetics in many regions.
Now, a research team from Imperial College London has assessed 29 alternatives to microbeads for their environmental impact.
They found that silica, a naturally occurring and abundant mineral, was the best alternative, performing overall better than plastic microbeads across all categories. It is chemically inactive, non-toxic and naturally occurring, making it easy to source and process and unlikely to cause long-term negative effects, according to a statement.
Lead researcher Professor Nick Voulvoulis said: “Not every apparently ‘natural’ alternative is desirable, so care is needed in selecting new cosmetic formulations.”
The team examined different plastic formulations, minerals like silica, salt and pumice, and plant and animal-derived products like almond shells, oats and pearls. For each alternative, they considered the environmental impact of their ‘life cycle’ and evaluated factors affecting environmental and human health, such as toxicity or ozone depletion.
They found that two major factors influence the environmental credentials of the materials: the amount of energy-intensive processing they require (creating greenhouse gases), and, for plant-based materials, the amount of land and water they require, explains the statement.
Image credit: MPCA Photos, flickr/Creative Commons