nonozonedepleting

Nonozonedepleting refers to chemical substances that have zero ozone depletion potential (ODP). ODP is a relative measure of how much a substance releases halogen radicals, such as chlorine or bromine, in the stratosphere to destroy ozone. Substances with an ODP of 0 are considered nonozonedepleting, meaning they do not contribute to ozone layer thinning as defined by international agreements such as the Montreal Protocol.

In practice, most compounds that do not contain chlorine or bromine have zero ODP. This includes simple substances like carbon dioxide, ammonia, and many hydrocarbons (for example propane and ethane), as well as fluorinated gases that lack chlorine or bromine, such as many hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs). While nonozonedepleting, these substances may still pose other environmental concerns, notably global warming potential (GWP). Some nonozonedepleting refrigerants and solvents are potent greenhouse gases, and their climate impact is a major consideration in policy and industry.

Regulatory context: The Montreal Protocol targets ozone-depleting substances with nonzero ODP. Substances with zero ODP are not controlled for ozone loss, but some have been regulated or phased down for climate reasons, notably through the Kigali Amendment addressing HFCs due to high GWP. Handling considerations include flammability and toxicity, which influence safe use and alternatives.

Applications and alternatives: Nonozonedepleting substances are used in refrigeration, air conditioning, insulation foams, solvents, and fire suppression. Safer or lower-GWP alternatives continue to be developed to balance ozone safety with climate and safety concerns.