Regulatory frameworks need to distinguish persistent from transient plastic fragments

Plastic particles below a diameter of 5 mm are often grouped together under the label ‘microplastics’ in current Environmental Impact Assessment protocols, regardless of their environmental half-life. We argue for a fundamental shift in nomenclature and regulatory frameworks: microplastics should be regulated according to degradability, with separate categories for transient and persistent particles. Plastic particles below a diameter of 5 mm are often grouped together under the label ‘microplastics’ in current Environmental Impact Assessment protocols, regardless of their environmental half-life. This Comment argues that microplastics should be regulated according to degradability, with separate categories for transient and persistent particles.