A recent research by NASA has once again forced us to shift our focus toward the depleting ozone layer. According to the research, the depletion of ozone layer has reached unprecedented levels of up to 40 percent compared to previous reading of 30 percent. The ozone layer protects life on Earth from the Sun’s ultraviolet rays by preventing passage of harmful UVB wave length through the stratospheric layer of the atmosphere.
Depletion of ozone layer was for the first time identified during the 1980s. Chlorofluorocarbons (CFCs) and other halogenated substances are mainly responsible for man made ozone depletion.The catastrophic effect of depleting ozone layer is already visible in the form of damage to crops and plants, increased risk of skin cancer, cataract and reduction of plankton population.
Its depletion had generated worldwide concern that lead to the adoption of Montreal Protocol Treaty. This treaty regulates the manufacture of chemicals that damage the ozone layer and at the same time encourages member nations to search for other ozone friendly alternatives. Depletion of ozone layer occurs when intense cold conditions induce radical catalytic reactions that convert atmospheric chlorine from artificially produced chemicals into atomic halogens which destroy ozone. The main source of this halogen is the photo dissociation of man made halo carbon refrigerants and aerosols such as CFCs, HCFCs, fleons and halons. All these are together referred to as Ozone Depleting Substance (ODS).
Though the list of ODS is not exhaustive, some commonly used products have been identified that have a substantial effect on the atmospheric ozone layer. The 5 most commonly used products that make it to the list are:
An inhaler is a quite commonly used medical device for injecting medicine into the body via lungs. Inhalers are used mainly in the treatment of asthma and Chronic Obstructive Pulmonary Disease (COPD). The most common type of inhaler is the Metered-dose inhaler (MDI) where the medication is stored in solution in a pressurized canister that contains a propellant. Upon activation, a fixed dosage of medication is released in the form of aerosol. This releases CFCs into atmosphere. Although in 2009 the FDA banned the usage of CFC propellant inhalers, scientists are yet to come out with a feasible alternative.
2. Fire extinguisher
Using a fire extinguisher to put out a small fire can save lives and property. But it also causes depletion of ozone layer. Fire extinguishers contain halo alkanes that are a threat to the ozone layer.
3. Aerosol hairsprays
Hairsprays as a class of personal care product is a common household name. The main purpose of the spray is to help hair hold a desired style. Hairsprays are devised as either aerosols where the spray is disbursed through a nozzle aided by pressurized gas or non aerosols that are dispensed by a pump manually. Aerosol hairsprays are chemical cocktails of solvents, glues, polymers, and propellants. Propellants, as implied by their name, aid in propelling the hair spray out of the can.
Originally CFCs were used as propellant but owing to their complicity in the depletion of ozone layer, they have been completely banned. Currently non CFC aerosols hairsprays are available which use HFCs instead of CFCs. HFCs though inert to environment and a contributor to global warming are indeed ozone friendly. Developing countries still use CFC aerosol hairsprays whereas it has been completely phased out in developed nations.
4. Wasp and hornets sprays
There are a host of conventional wasp and hornet sprays that are easily available in the market at a very affordable cost. No doubt in the fact that the sprays help in pest control, protect our houses but these sprays are a cause of major concern due to their impact on the ozone layer. As with majority of the sprays, wasp and hornet sprays also use CFCs and HCFCs as a propellant. The Environmental Protection Agency (EPA) has even made it mandatory to use such sprays near high tension power lines. The agency has also given clear guidelines to all the sellers to alert the buyer about the usage and restrictions.
5. Foam insulation product
Foam insulation is an alternative to traditional insulation. It is widely used in electronic appliances such as refrigerators and air conditioners and in pipe insulation. Foam insulation helps in filling vacant air gaps. Commonly used foam insulation product consists of HCFC blowing agents. The HFC variants are yet to be implemented worldwide.
The products listed above are just a few among the plenty. While countries all round the globe have started to realize the importance of ozone layer and have started taking curative measures to prevent further depletion, it is still a long way to go.