Yesterday, I wrote about an arcane development called the scrubber which promises to rid the Earth of all CO2. The theory may or may not come to fruition, but now here's another application to which this 'greenhouse' villain can be put to.

Tattoos have become a part of our mainstream culture. It’s their on arms, legs, heads and even other unmentionable parts of the human anatomy. In vogue it’s as necessary as an earring perhaps. But this fashion statement comes with a small rider. It is more painful to remove than it is to apply. An American study had found that nearly 50 percent who went in for a tattoo later regretted their decision. For many years, tattoo removal required invasive technique like surgery, dermabrasion or excision. It took a pinch out of your wallet not to mention your skin.



These procedures are still in use today, but now lasers are preferred widely for there non-invasive and low risk properties. Lasers are used in several short high energy bursts called 'pulses'. The pulses cause the pigments to fragment into smaller particles which are subsequently absorbed by the body. Though it sounds scientific, tattoo removal is a painful procedure. Someone has said that it feels like being snapped repeatedly by a thin rubber band. And it usually takes quite a few sessions to remove all traces of the tattoo marks. Surgeons have to be careful as too much energy impact of the lasers on the skin can cause hyperpigmentation and in 5 percent cases - scarring.

The threshold temperature to prevent scarring is 70 degrees (Celsius). To increase the threshold temperature specialists use a compound called tetrafluoroethane.

Tetrafluoroethane is a refrigerant which reduces the ambient temperature of the skin to around 3 degrees allowing the laser process to be prolonged. Tetrafluoroethane is an inert gas with primary applications in refrigeration and air conditioning. It is also used to cool computers in overclocking experiments and sometimes as a propellant in air guns. New evidence shows that this compound can be a contributory to climate change as a greenhouse gas. It is also believed to be more potent than carbon dioxide.

Tetrafluoroethane is a chlorine free hydro fluorocarbon with no ozone depletion propensity. However, it has been suggested that they can make a significant contribution to global warming in comparatively low concentrations. Though it is an excellent choice as a cryogenic gas, it has a high global warming potential.

Now, specialists like John Stuart Nelson, Medical Director at the Beckman Laser Institute of the University of California, Irvine, US, believe that carbon dioxide used as a coolant can solve the problem. Being less potent to the atmosphere (with a Global Warming Potential of 1), it can replicate and replace the use of tetrafluoroethane (with a GWP of 1,200) in tattoo removal surgeries. His idea involves the use of a pressurized carbon dioxide as a spray on the target area. Liquid CO2 results in dry-ice formation immediately after leaving the spray nozzle. The fine mist of CO2 or 'dry ice' has similar cooling properties and thus offers a more environmentally viable option to the earlier gas.

Now whether it's a broken heart or just a whim, you can remove your tattoo without pricking your eco-conscience.

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