The Montreal Protocol on Substances that deplete the Ozone Layer was adopted in 1987 as an International Treaty to eliminate the production and consumption of ozone depleting chemicals. This treaty was signed by 110 countries and India became a party to the Montreal Protocol in 1992 and has thereafter committed itself to stop the use and production of such chemicals, which damage the ozone layer and the environment. One of the chemicals which damage the ozone layer and the environment is Chlorofluorocarbon gas, popularly known as CFC’s. This gas was used as a propellant in aerosol products such as Silicone Spray.
All over the world, most aerosol products have substituted the use of CFC’s with Hydrocarbon Aerosol Propellants (HAP) and Hydro Fluoro Carbons (HFC).
Like LPG, HAP is highly flammable and as a result, most aerosol products including Silicone Spray have become highly flammable. HFC is also used to manufacture Aerosol Sprays but it makes them expensive. Many enterprises in India have started the use of LPG and HAP as a propellant in the production of Aerosol products, recently and the Government of India has banned the use of CFC’s in aerosol products w.e.f. 01.01.2003.
Besides having all its contents in pressurized containers, the use of HAP as a propellant makes Aerosol Spray a hazardous product. Consumers must understand the characteristics of HAP as discussed below and be aware of the hazards involved in the storage and use of Aerosol Spray.
- HAP is a mixture of propane and butane gases. At normal conditions HAP, like LPG, is heavier than air and therefore tends to settle down on the floor, in the absence of ventilation. The vapour may accumulate in depressions, pits and drains and remain settled there.
- A small amount of HAP in air gives rise to a very large Air-Vapour mixture that is capable of being ignited by a spark from an electrical switch or by the falling of a tool on the floor. To be exact, one gram of HAP will expand to 500ml of LPG vapor in air and mix with air to form 50 times the quantity of a flammable mixture. In short, one gram of LPG gives rise to 25000ml of highly flammable air vapour mixture.
- Flammable concentrations of air vapor mixture can travel through drains, depressions and inclination upto very long distances.
- Besides the above, all pressurized containers must be protected from body damage, puncturing & heat. These factors can cause pressurized containers to burst violently.
- The cans should be stored in a vertically upright position. Cartons of cans may be stacked on shelves or on pallets up to a suitable height.
- The storage should not be in the basement of a building. It should be on any floor other than the basement with adequate ventilation, especially at ground levels. The storage area should be free from sunken portions, pits, and trenches as far as possible.
- The area of storage should be away from sources of sparks, ignition and heat such as electrical connection, switches, radiators, batteries, boilers and direct sunlight. The storage temperature should be below 50° C
- The story/warehouses should be free from other inflammable materials, hazardous chemicals such as Acids, Alkalis and other oxidizing materials as far as possible.
- The area of storage should be free from risks of heavy objects and materials from falling on the cans of Aerosol Spray.
- Do not use large quantities of Aerosol Sprays in basements and small rooms without adequate ventilation.
- It is always advisably to wear eye protection, if using large quantities, regularly.
- Use Aerosol Spray away from sources of sparks such as Switches, Control Panels and Batteries.
- Do not keep ‘in-use’ cans on or near hot surfaces such as Boilers, Radiators, Furnaces etc.
- Do not attempt to cool hot surfaces or extinguish flames by spraying Aerosol Spray on such surfaces.
- Do not use Aerosol Spray in confined, non-ventilated areas where welding and metal cutting operations are going on.
- Avoid dropping cans from a height. This may cause the can to explode violently.
- Do not puncture cans or attempt to break open cans by hammering.
- Avoid excessive inhalation and do not spray into eyes, mouth and open wounds.
- Do not smoke while using Aerosol Sprays. As far as possible the area of use should be a No smoking area.
- Keep the floor area adequately ventilated and free from litter.
- Obtain a MSDS (Material Safety Data Sheet) from the manufacturer and ensure the concerned workers are acquainted with it.
Used cans may contain residual HAP vapour and therefore can be as hazardous as filled cans. Often, used cans are assumed to be non-hazardous. As most cans are made of recyclable material, i.e. Tinplate or Aluminum, they can easily be sold off as scrap.
Prior to their disposal, it is advisable to empty out the contents fully during use and puncture the cans using a long nail and non-sparking hammer. This activity should be done in the open, away from sources of ignition.
Such depressurized cans may be disposed as scrap as they are no longer hazardous. This will further prevent unauthorized re-filling of cans.
The following guidelines should be followed for their storage, transport and disposal.
- Do not store used cans in sacks, gunny bags etc. always store in the suppliers cardboard cartons and ensure that the valve remains in ‘off’ position. Stacking in gunny bags or in disorderly fashion may press the valve and release residual HAP vapour.
- Do not dispose cans in an incinerator. This may cause the cans to burst violently.
- Do not throw cans on the roof of buildings or open areas, direct sunlight may heat up the can causing it to deform or burst.
- Do not transport or store used cans along with spark producing materials such as metal components, static plastics, batteries etc.
- Keep disposing of scrap at short intervals so as to avoid accumulation of used cans.