Way forward in the Twelfth Malaysia Plan 2021-2025 (2021) is towards low carbon growth with strategies, such as transition to circular economy which is one of the focus for the research in using recycled materials as a sustainable alternative to the existing heating, ventilation, and air-conditioning (HVAC) insulation materials. In response to the challenges with regards to the green building materials, the study aims to explore potential sustainable alternative HVAC thermal insulation to the existing insulation materials in the market. Rockwool (fibreglass), open cell nitrile rubber, and open cell polyurethane (PU) foam were tested for the presence of metallic and non-metallic elements, and alkalis by way of X-ray fluorescence spectroscopy. The chemical elements present consist of post-transition metals (Silicone and Aluminium), a range of transition metals (Iron, Zinc, and Copper), halogen (Chlorine), non-metal (Sulphur) and alkali earth (Magnesium and Calcium), which may contribute to the insulation material being non-degradable, thus pose a risk to the environment and human beings. Future research area should focus on the feasibility of integrating with recycled or natural materials to reduce the chemical content.