The application of carbon dioxide (CO2) in the wider realm of cryogenics usually involves the freezing of food products, plus select applications in industrial processes. There is a small market for cryotherapy and usage as a respiratory stimulant.

Also covered in this writing, is an update on the US greenhouse gas legislative efforts pertaining to CO2, and the Environmental Protection Agency’s (EPA) position on CO2 today.

Cryotherapy involves using cryogenic agents to achieve specific medical procedures. With respect to cryotherapy, CO2 (solid or snow), liquid nitrogen (LIN) or DMEP (dimethyl ether & propane) are the three common agents used to achieve such a task.

Initially when speaking of CO2, solid CO2 was more commonly used years ago rather than LIN which is more readily used today, in the developed world.

As for CO2 usage in cryotherapy, this practice generally surrounds the removal of specific skin lesions, but not for the treatment of melanoma. Full-blown cryosurgery is another topic, and not specific to CO2 usage.

More specifically, various forms of keratosis and viral warts on the skin surface are removed via cryotherapy.

After a standard freezing application, the ultimate appearance may vary widely; the skin may result in an entirely normal appearance, to one which has a loss of pigment (hypopigmentation), or even to scarring – particularly when freezing the lesion deeply or in a prolonged manner.

The long term result may be anything from a normal skin appearance, to a dramatically altered appearance. In terms of CO2 by volume, when it should be used in this process, the volume is very small. All references to this application call for dry ice or ‘solid CO2’.

Respiratory stimulation
In summary, the practical application for gaseous CO2 as a United States Pharmacopoeia (USP) grade product, when applied as a respiratory stimulant, suggests usage up to 5% in this application – when inhaled in a defined manner.

Some interesting and relevant background on the subject surrounding human and animal CO2 emissions, and the association with varying levels of this gas are as follows. On average, each person’s breathing produces about 2-3 pounds, or near 1kg of CO2 per day. Human emissions account for some 2-3% of all natural emissions globally.

In the spring of 2009, the average CO2 atmospheric content was 387 ppm, per some official estimates; this otherwise represents 0.0387%. CO2 is considered to be unhealthy to animal life at levels nearing 5,000 ppm or 0.5% for a prolonged period.

At over 1%, or 10,000 ppm, CO2 will at the very least cause drowsiness. At 7-10% dizziness, visual dysfunctions, and unconsciousness will occur within minutes to an hour or two.

Typically we exhale 4-5% CO2 and about 4-5% less oxygen (O2) is contained in our exhaled gases compared to the atmospheric gases which were inhaled. Then, relating to all animal life, there is an essential exchange of O2 and CO2 in the blood through the lungs or gills.

In aerobic respiration, O2 must enter our blood and CO2 must leave the blood through the lungs – as land-bound animal and human life.

A gaseous exchange is an exchange of O2 and CO2 across a large respiratory surface – that being our lungs. On the other hand, water borne animals use gills for this exchange. The exchange of O2 and CO2 across the surface area of the lungs through the blood is a rapid process.

Carbon dioxide, among a number drugs, is a useful agent in stimulating the process of respiration – however in depth, the philological process surrounding respiration on a cellular level can be rather extensive.

Although the body requires O2 for metabolism, low O2 levels do not simulate breathing. However breathing is stimulated by higher CO2 levels and experts suggest respiratory stimulation via CO2 gas can be at a level of 5%.

With the ever important subject of plant life, and the CO2 – O2 cycle; via the process of photosynthesis, there is the exchange of O2 and CO2. Green plants respire – at night they exchange gases as we do, O2 in, and CO2 out.

In the daytime, just the opposite occurs – CO2 enters the plant as needed for photosynthesis and O2 leaves the plant, which in turn we use during respiration.

Greenhouse gas legislation update
As you may know, around 17th April 2009 the EPA administrator proposed carbon dioxide to be a hazardous greenhouse gas, and is a threat to public health – notice the word proposed in this official statement by the EPA.

This is the first official significant announcement made on the subject of CO2 from the EPA. In many ways, the EPA took the first step toward creating a national cap and trade system, thus proposing a new rule which would establish a federal system for the reporting of CO2 and several other greenhouse gases (GHG) produced by stationary and mobile sources.

Until now, the focus has been on electric utility plants, primarily those which are coal fired, which is probably the major CO2 emitter nationally (power plants at large represent some 40% of all CO2 emissions).

Under such a ruling, fossil fuel and industrial chemical manufacturers – including ethanol producers, among other emitters, would need to adhere to a new code of reporting and follow-up when emitting at least 25,000 TPY (metric) annually.

2. US Senator Cantwell proposed an alternative to cap and trade. The feeling was cap and trade may be abused, and lead to another un-regulated money making scheme, which has fuelled the current economic crisis. This alternative mechanism could be a cap and dividend option; requiring companies to pay for credits or allowances, and this fund in turn would be reimbursed to the taxpayers.

Conversely, the taxpayers, ultimately would endure higher utility bills, since much of this legislation would impact the electric power industry’s coal fired power plants.

3. Other politicians have proposed outright carbon taxes as opposed to the two schemes outlined above.

4. The EPA has indicated that whatever action is taken in terms of addressing CO2-based greenhouse gases, the mechanism which will be enforced will need to exceed 25,000 TPY – this would be on a source-by-source basis, probably to include ethanol and most other by-product sources for raw CO2 feedstock, which are used by the merchant market.

5. The company would be responsible for its emissions – from a reporting, permitting, and compliance point of view. If the gas is sold to a refiner, or sequestered, then the liability would be zero for said CO2 emissions – and ongoing monitoring will probably be essential in any event.

6. Should the said raw CO2 gas source, or emitter, such as an ethanol project dislocate their refiner or sequestration destination in the future, then the reporting and handling of emissions and related mechanisms under the law would then be handled differently.

7. Today, numerous schemes for handling carbon emissions are being proposed on Capital Hill and each single source in excess of 25,000 TPY of CO2 emitted will have to address the subject, once the mechanisms have been established.

8. As for implementation of said mechanisms for handling carbon emissions, even if a bill is passed soon, more than likely the earliest date for start-up of the programmes chosen will be 2012; or more than likely 2013. The question of timing for implementation of certain industries is a further subject to be addressed.

9. In the end, whether this is cap and trade, cap and dividend, or outright taxation on carbon emissions, monitoring of CO2 emissions will probably be essential – as well as a need to acquire permits in accordance with the mechanism(s) chosen.

Over the next weeks and months, the philosophy, options, and implementation will be further addressed across The Administration, Capital Hill, and The EPA.

What we know presently, is that a form of handling emissions, reporting, and permitting carbon emissions will be in place within the next few years in the US.

This is both a dramatic development and worlds apart from the view and handling of CO2 under the prior US administration.

10. As of 21st May 2009, The American Clean Energy and Security Act passed through a US House Committee and if approved, the bill would then in fact institute the nation’s first cap and trade system.

This means slashing emissions 83% below 2005 levels by 2050. By 2020, all electric utilities must produce up to 15% of their power from renewable sources; and of the tradable carbon credits, 15% would be auctioned off – the rest donated to select industries, thus reducing the bill’s economic impact.