evidence: Vegan leather, a cruelty-free and environmentally friendly substitute for animal and synthetic leather (essentially made of plastic) has long been the holy grail of sustainable fashion. [...] Most "leather" that is branded vegan is polyvinyl chloride (PVC) and polyurethane (PU) or some form of natural material combined with PU. While this synthetic leather has a lower environmental impact, according to the Nature Sustainability study, and is of course animal free, the manufacturing process uses hazardous chemicals and it’s also made from fossil fuels. And like most plastics, the material takes centuries to break down, according to the study. [...] A number of startups are banking on consumer interest in a truly vegan fungi leather. Some 66% of US respondents to a survey by consulting firm McKinsey & Company said they consider sustainability when making a luxury purchase.