The new package will fund projects that will support efforts made by health boards and NHS organisations to cut carbon dioxide emissions by more than a third by 2030.
It has committed to cutting the use of high global warming potential inhalers to less than 20% by 2025 from the current 70%.
People who use inhalers are advised to ask their prescriber to switch their regular inhaler to a low carbon alternative.
NHS Wales Chief Executive Judith Paget said: “As the largest public sector emitter of carbon dioxide, the NHS in Wales needs to play its part to protect the health and wellbeing of future generations.
“We can all help with this effort by returning unused medication to their pharmacy, asking for a more sustainable inhaler or using active or public transport to attend appointments.”