Approximately 73 million inhalers are prescribed in the UK annually, which currently constitutes around 3% of total NHS UK emissions. The majority of inhalers — many of which contain chemical propellants that are known greenhouse gases, plastic and aluminium — are disposed of through the municipal waste collection process. Disposal through municipal waste streams can lead to the devices being transferred to landfill sites, the propellant leaking into the atmosphere and the other materials being unrecoverable.