Operating across 12 countries, including Australia, America and South Africa, Bristol-based A-Gas supplies the refrigerants used to air-condition buildings and chill food. It also provides industrial gases and fire suppressants, and reclaims waste gases for resale. Led by chief executive Andrew Ambrose, 58, and majority-owned by private equity firm KKR, it grew overseas sales to £205.7 million in 2019. In November, it acquired Italian firm Safety Hi-Tech for an undisclosed sum.