Nu-Calgon has developed the Green Select products with all natural ingredients derived from vegetable esters and other eco-friendly resources. All of the Green Select products have been tested extensively to ensure the highest level of performance while utilizing green ingredients. In addition, the products are biodegradable and will not harm plants, animals, and aquatic life. More importantly, we use only natural and renewable resources that are on the EPA's Designed for the Environment list of acceptable green ingredients. Cal-Green is an all natural environmentally friendly condenser coil cleaner. This low-foaming, non-toxic cleaner is outstanding for removing dirt and grime which hinders heat transfer. By cleaning the fins with Cal-Green you restore the units efficiency while being environmentally responsible.