CO2/Carbon dioxide usually behaves as a gas in air at standard temperature and pressure (STP), or as a solid called dry ice when frozen. If the temperature and pressure are both increased from STP to be at or above the critical point for carbon dioxide, it can adopt properties midway between a gas and a liquid. Carbon dioxide (CO2) is a supercritical fluid, meaning it converts into a liquid form when pressurized. Supercritical carbon dioxide (sCO2) is a fluid state of carbon dioxide where it is held at or above its critical temperature and critical pressure. Subcritical CO2 extraction uses CO2 in its liquid state, below its critical point.At the same time, it is a pure chemical substance that occurs naturally and leaves behind no residues. Accordingly, the CO2 extraction method can help ensure cannabis concentrates are pure, making it a good option for patients in search of a natural form of cannabis extract. Although liquid CO2 does not possess the incredible diffusivity of supercritical fluid, its density is far greater. In fact, 95% of all cannabis extractions are done in the subcritical phase before moving onto to the supercritical phase.
Don’t let the term LIQUID CO2 confuse matters. All that is required to dispense CO2 in it’s liquid state is a standard high pressure Carbon Dioxide tank with a siphon tube. Also known as a "Co2 Siphon Tank" or "Dip Tube Tank". The Siphon tank has a tube that runs down the center to dispense the liquid Co2. ... Most standard Siphon tanks come in 20, 50 or 75 pounds. Larger cylinders known as a dewar, are also available. Dewars release much lower pressure than a standard high pressure tank. Normally Co2 tanks are not purchased they are rented by the day or week etc. You can still purchase the tanks from and get them refilled at any local welding supply shop or gas suppliers. Because of the weight and maintenance we recommend to rent them. You can also have the local Co2 supplier deliver to your venue or site.
CO2 can evaporate into the air or be recycled by condensation into a cold recovery vessel. The Resinator allows for plant material to tumble while “gas" is injected into the chamber for the coldest possible temperatures. Commonly extracted undesirable compounds left over from traditional extraction methods may include pigments such as anthocyanin, chlorophyll, tannins, saponins, and lipids from cellulosic materials. While others are busy catching undesired male Pollen, we extract only the pure essence of botanical female Resin glands from your dried flowers and plant clippings. Sift undesired plant material, stems and particulates leaving only the desired micron rated trichomes to fall through our high quality monofilament screens. Escape from the world of residue left over from a solvent extractions. Use our Extraction Guide for suggested run times, speeds and load sizes. Our Instruction Manual & Instructional videos help to explain this process step-by-step.
Extract high quality resin glands for a wide variety of applications including:
Freeze Flash-freezing is the best available method to extract resin glands & trichomes.
Fracture Dry cryo-fracture ruptures frozen plant tissues in preparation for subsequent extraction.
Extract Our extraction system has been designed to achieve easy workflow from flash freeze to point-of-collection.
• Save time and increase yield with multi integrated function and rapid workflow.
• Preserve precious botanical essence by flash freezing with efficiency and ease.
• Maintain ideal environment for proper extraction and continuous temperature control.
• Experience efficient extraction with round and clear convenience.
• Extract high quality resin glands.
THE POWER OF CO2 EXTRACTION
A SAFER, CLEANER, PURER & FASTER BOTANICAL EXTRACTION
Non-Toxic. When it comes to botanical extractions… no toxins, heavy metals or hydrocarbon materials come in contact with the extracted oils. Generally Regarded as Safe (GRAS) by the FDA for use in food products and commonly found in carbonated beverages. Our bodies produce it when we breathe!
Pure. Extracted material is free of residual solvents.
Natural. Other extraction solvents, such as hydrocarbon-based propellants like propane and butane, hexane and pentane, or ethanol/alcohol mixtures, require additional distillation or purging beyond the extraction process to separate the solvent from the extracted concentrate. CO2 has a very low boiling temperature and wants to be a gas at room temperature, so it naturally separates from the extracted oil, the same way a soda goes “flat.”
Non-Flammable. Does not require costly explosion-proof facilities like flammable solvents do.
Cold. CO2 extractions can be done at temperatures native to the plant, minimizing thermal degradation of the plant material and the extraction.
Adjustable. The solvency power of CO2 can be adjusted simply by increasing or decreasing pressures and/or temperatures. The ability of the CO2 to selectively extract affords the ability to create unique extractions that have varying levels of desirable resins, oils and waxes. Additionally, less desirable plant constituents, like chlorophyll, can be “de-selected”.
Cost-Efficient. CO2 is readily available and widely used throughout a number of industries.
Convenient. Use when your ready, unlike dry ice due to sublimation.
Environmentally Friendly. Industrial CO2 for extractions comes from byproducts – primarily hydrogen and ammonia manufacturing and fermentation for ethanol. CO2 used for extractions does not contribute to the overall atmospheric CO2 levels.
COMPARING CO2 EXTRACTION VS. BUTANE OR PROPANE?
Aside from the inherent dangers, don’t forget to include the facility cost for processing with a compressed flammable gas.
TYPES OF CO2 EXTRACTION (SUPERCRITICAL & SUBCRITICAL EXPLAINED)
CO2 extraction is a process that uses pressurized carbon dioxide to pull the desired phytochemicals (such as CBD) from a plant. CO2 at certain temperatures and pressures acts like a solvent, without the dangers of actually being one. CO2 is unique because its solvency power can change by simply adjusting the temperature and pressure during the extraction. When the pressure and temperature of the CO2 are above 1083psi AND88F, the CO2 is considered supercritical. Expanding to fill its container like a gas but with a density like that of a liquid. If the temperature drops below 88F, the CO2 changes to a liquid and is referred to as subcritical. Both supercritical and subcritical CO2 act like a solvent and can extract resins, oils & waxes from plant material. When the pressure of the CO2 is decreased (generally to below 600psi) it converts to a gas and loses its ability to hold it’s state in solution and separates the extraction from the now gaseous CO2. It is widely considered the most effective and safest plant extraction method in the world. CO2 extraction is already a standard extraction method for the food and herbal supplement industries. CO2 is a common food additive as well. In fact, CO2 is used to produce carbonated soft drinks, in the removal of caffeine from coffee beans in order to make decaffeinated coffee, and as an extraction solvent when producing essential oils. Supercritical CO2 is becoming an important commercial and industrial solvent due to its role in chemical extraction in addition to its low toxicity and environmental impact. The relatively low temperature of the process and the stability of CO2 also allows most compounds to be extracted with little damage or denaturing. In addition, the solubility of many extracted compounds in CO2 varies with pressure, permitting selective extractions. Most often we hear about supercritical CO2 extractions, but that’s actually only one method of CO2 extraction. You can also perform subcritical CO2 extractions, and ‘mid-critical’ extractions, a general range between subcritical and supercritical.
With respect to botanical extractions, subcritical CO2 has lower solvency power and thus tends to pull mostly lighter extractions and leaves behind majority of undesired plant material. Subcritical CO2 is also relatively cold and therefore very effective in extracting temperature-sensitive volatile oils and terpenes. Subcritical CO2 is ideal for extracting and preserving light resin glands and oils from the plant material. Subcritical (low temp, low pressure) CO2 extractions take more time and produce much smaller yields than supercritical, but they retain the essential oils, terpenes, and other sensitive chemicals within the plant.
Supercritical CO2 can be a much stronger solvent than subcritical CO2. In addition to extracting lighter oils, supercritical CO2 can extract the higher molecular weight materials (like waxes, paraffins, lipids and resins) from the plant, allowing for higher yields and a more complete extraction. The stronger solvency power also makes the extraction times faster. Supercritical CO2 extractions at very high temperatures and pressures (higher than 120F and 5000psi) can cause thermal degradation of the oils, and when extracting green plant materials can have the potentially negative consequence of extracting chlorophyll. Supercritical, on the other hand, is a high pressure and high temperature process that damages most terpenes and heat sensitive chemicals, but can extract much larger molecules in addition to chlorophyl such as lipids (omega 3 and 6), paraffins and waxes.
(sCO2 pics shown range from $39,000 - $279,000+)
Running CO2 extract at sub critical, over super critical levels obtains a cleaner initial extract.Test lab results generally measure cannabinoid terpene profiles were saved at the lower temps. Sub critical extractions produce better quantity, while super critical will achieve higher quantity.
Truly full-spectrum CO2 extracts include first performing a subcritical extraction, separating the extraction, then extracting the same plant material using supercritical pressure, and finally homogenizing both oil extracts into one.
*WHEN UTILIZING CO2 BE SURE TO OPERATE IN A WELL VENTILATED AREA.
CO2 Levels & Monitoring Explained
What is a CO2 Monitor and Why Does it Matter?
A CO2 Monitor is a device that helps you record and understand the environmental Carbon Dioxide (CO2) levels in an office, room, building, factory, hospital or any other area. A CO2 Monitor can take once-off readings (with a handheld or portable reader), or automatically take readings over a period of time for you to review later (with a data logger, or CO2 logger).
It is important to monitor CO2 levels because they directly influence the mood, productivity and health of those exposed to CO2. Incorrect CO2 levels can cause stiffness, odours, drowsiness, and reduced productivity. Higher levels, or prolonged exposure, can be very harmful to health.
What Causes Indoor CO2 Levels to Rise?
The main cause of Carbon Dioxide indoors is people. The more people in an area, the more CO2 is emitted. Respiration of humans introduces this CO2. The amount emitted from one working person can be from 0.08m2 to 0.38m2 per hour, depending on the intensity of their work
Gas operated devices such as heaters and kitchen appliances can also introduce CO2 into the area. It is also worth noting that CO2 is the main gas involved in the greenhouse effect, so higher levels of CO2 can be observed in areas with many windows (such as floor to ceiling windows in offices). The setup of the air conditioner and the proportion of indoor air to outdoor air being circulated will determine how this equates to the overall CO2 level in a room.
Understanding CO2 Levels
CO2 Levels are measured as PPM (Parts Per Million). The standard outdoor level is around 350ppm, and is the optimum level for freshness. However, you can generally get up to 600ppm indoor without any adverse affects. As you can see in this chart, once you get past 600ppm you will start noticing adverse affects.
CO2 levels have a noticeable impact on one's productivity and wellbeing. The higher the levels, the lower the productivity. The lower the levels, the better one can work. This is why it's important to measure and constantly conduct CO2 Monitoring within your workplace.
Standards & Regulations
Almost every jurisdiction has standards and regulations which set out the maximum acceptable exposure to CO2 in workplaces and schools. Safe Work Australia's "Adopted National Exposure Standards for Atmospheric Contaminants in the Occupational Environment" outlines a Time Weighted Average of 5000ppm. This means average airborne concentration of Carbon Dioxide mustn't exceed 5000ppm.
There are other similar international standards which specify their own acceptable CO2 exposure limits:
The USA's Occupational Health & Safety Administration (OHSA) sets the limit at 5000ppm over an eight hour working day.
Schools in the United Kingdom mustn't be exposed to over an average level of CO2 over 1500ppm in a standard school day.
The Environmental Protection Administration in Taiwan sets a daily limit of 1000ppm in indoor areas, with a suggested level of 600ppm in areas such as schools, hospitals, and day care centres.
Please check with your local authorities for the latest standards which apply to you.
How to Reduce CO2 Levels Indoors
Here are some practical steps to lowering your CO2 and ensuring it stays low:
Increase ventilation from outdoors This is the big one, and is key to reducing CO2 levels indoors is proper ventilation. Outdoor CO2 levels should be below 400ppm, so ensuring more fresh outside air is brought indoors is the key to lowering your Carbon Dioxide.
Check and maintain your HVAC (Heating, Ventilation and Air Conditioning) System Some offices are sealed very well, which is good for energy efficiency in your HVAC system as it doesn't need to cool hot air often. However, it means you have very little fresh air coming in and the CO2 levels will just keep building. Other systems will actually actively bring in air from an outside vent and mix it with the inside air – this is preferred as it is constantly lowering your indoor CO2 levels.
Check gas devices for leakage and cross ventilation Leaking gas devices can cause the CO2 level to rise. Preferably get the device repaired or replaced so it doesn't continue to leak. Failing this, open a window on the opposite side of the room to allow for cross ventilation.
To determine the CO2 levels in the room, you first need to purchase a CO2 Measurement Reader. These come in two forms: a CO2 Meter and a CO2 Data Logger.
A CO2 Meter, available in handheld and desktop form factors, will take on-the-spot readings for you and provide the information in real-time. These are perfect for checking lots of different areas at one point in time.
A CO2 Data Logger will provide you with ongoing readings at a set interval (e.g. every five minutes) which can later be viewed on your computer as a table for graph for analysis. These are perfect for more detailed analysis of one area over a longer period of time.
In laboratories, sCO2 is used as an extraction solvent, for example for determining total recoverable hydrocarbons from soils, sediments, fly-ash and other media, and determination of polycyclic aromatic hydrocarbons in soil and solid wastes. Supercritical fluid extraction has been used in determining hydrocarbon components in water.
Processes that use sCO2 to produce micro and nano scale particles, often for pharmaceutical uses, are under development. The gas antisolvent process, rapid expansion of supercritical solutions and supercritical antisolvent precipitation (as well as several related methods) process a variety of substances into particles.
Due to its ability to selectively dissolve organic compounds and assist the functioning of enzymes, sCO2 has been suggested as a potential solvent to support biological activity on Venus- or super-Earth-type planets.
Work is underway to develop a sCO2 closed-cycle gas turbine to operate at temperatures near 550 °C. This would have implications for bulk thermal and nuclear generation of electricity, because the supercritical properties of carbon dioxide at above 500 °C and 20 MPa enable thermal efficiencies approaching 45 percent. This could increase the electrical power produced per unit of fuel required by 40 percent or more. Given the volume of carbon fuels used in producing electricity, the environmental impact of cycle efficiency increases would be significant.
Supercritical CO2 is an emerging natural refrigerant, used in new, low carbon solutions for domestic heat pumps. Supercritical CO2 heat pumps are commercially marketed in Asia. EcoCute systems from Japan, developed by Mayekawa, develop high temperature domestic water with small inputs of electric power by moving heat into the system from the surroundings.
Supercritical CO2 has been used since the 1980s to enhance recovery in mature oil fields.
"Clean coal" technologies are emerging that could combine such enhanced recovery methods with carbon sequestration. Using gasifiers instead of conventional furnaces, coal and water is reduced to hydrogen gas, carbon dioxide and ash. This hydrogen gas can be used to produce electrical power In combined cycle gas turbines, CO2 is captured, compressed to the supercritical state and injected into geological storage, possibly into existing oil fields to improve yields. The unique properties of sCO2 ensure that it remains out of the atmosphere.
Supercritical CO2 could be used as a working fluid in enhanced geothermal systems. Possible advantages compared to water include higher energy yield resulting from its lower viscosity, better chemical interaction, CO2 storage through fluid loss and higher temperature limit. As of 2011, the concept had not been tested in the field.
Dry Ice Extraction
See the Resinator in action!!!
Dry ice, sometimes referred to as "cardice" (chiefly by British chemists), is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere). It is useful for preserving frozen foods where mechanical cooling is unavailable.
Dry ice sublimates at −78.5 °C (−109.3 °F) at Earth atmospheric pressures. This extreme cold makes the solid dangerous to handle without protection due to burns caused by freezing (frostbite). While generally not very toxic, the outgassing from it can cause hypercapnia (abnormally elevated carbon dioxide levels in the blood) due to buildup in confined locations.
Using Dry-Ice with The Original Resinator
How to use dry ice for resin extractions?
We recommend that you start with a 125 to 150 micron bag (depending on strains and needs) and gradually reduce the screen size according to the gland concentration you want. As always, there are different types and sizes of trichomes. The morphology of these glands mainly depend on plant genetics, so we can find glands of up to 150mc and others measuring even less than 25-50mc.
To obtain a clean and professional extraction, we should try to recover those glands measuring between 75 and 125mc, which normally yield the best quality. If the screen sizes are smaller then the collected glands, than the dry sift extraction will also be smaller (the used screen size mainly depends on user preferences).
The dry ice or CO2, the solid form of carbon dioxide, isn’t very difficult to find, but it is difficult to carry and store. It can be bought easily and quickly on the internet or at companies who work with frozen or cold materials and some deliver them to your home. The main problem with dry ice is that it degrades fast when not stored under very special conditions, so we’ll have to use it as soon as we get it.
This is the main reason why it’s essential to have everything ready for a quick use, since we must use the solid CO2 as soon as we get it, otherwise it will quickly evaporate.
We will also need a plastic cup or bucket (to catch and pour the dry ice) and waterproof gloves to avoid burns: always remember that CO2 can cause severe burns in those parts of the body exposed for only a few seconds to it.
The first step will be to take the plant material out of the freezer. Freezing it isn’t really required but recommended. So when the organic matter goes in contact with the dry ice the resin glands are released easier and faster than with plant material at room temperature, thus achieving better yields and quality.Use the "Extraction Guide" for suggested run times and amounts to use. Our "Instruction Manual" shows this process step-by-step.
For supplementary chemical data, see Carbon dioxide data.
Dry ice is the solid form of carbon dioxide (CO2), a molecule consisting of a single carbon atom bonded to two oxygenatoms. Dry ice is colorless, non-flammable, with a sour zesty odor, and can lower the pH of a solution when dissolved in water, forming carbonic acid (H2CO3).
Comparison of phase diagrams of carbon dioxide (red) and water (blue) as a log-lin chart with phase transitions points at 1 atmosphere
At pressures below 5.13 atm and temperatures below −56.4 °C (−69.5 °F) (the triple point), CO2 changes from a solid to a gas with no intervening liquid form, through a process called sublimation. The opposite process is called deposition, where CO2 changes from the gas to solid phase (dry ice). At atmospheric pressure, sublimation/deposition occurs at −78.5 °C (−109.3 °F).
The density of dry ice varies, but usually ranges between about 1.4 and 1.6 g/cm3 (87 and 100 lb/cu ft). The low temperature and direct sublimation to a gas makes dry ice an effective coolant, since it is colder than water ice and leaves no residue as it changes state. Its enthalpy of sublimation is 571 kJ/kg (25.2 kJ/mol).
Dry ice is non-polar, with a dipole moment of zero, so attractive intermolecularvan der Waals forces operate. The composition results in low thermal and electrical conductivity.
It is generally accepted that dry ice was first observed in 1835 by French inventor Adrien-Jean-Pierre Thilorier (1790–1844), who published the first account of the substance. In his experiments, he noted that when opening the lid of a large cylinder containing liquid carbon dioxide, most of the liquid carbon dioxide quickly evaporated. This left only solid dry ice in the container. In 1924, Thomas B. Slate applied for a US patent to sell dry ice commercially. Subsequently, he became the first to make dry ice successful as an industry. In 1925, this solid form of CO2 was trademarked by the DryIce Corporation of America as "Dry ice", thus leading to its common name. That same year the DryIce Co. sold the substance commercially for the first time; marketing it for refrigerating purposes.
The alternative name "Cardice" is a registered trademark of Air Liquide UK Ltd. It is sometimes written as "card ice".
Dry ice is easily manufactured. First, gases with a high concentration of carbon dioxide are produced. Such gases can be a byproduct of another process, such as producing ammonia from nitrogen and natural gas, oil refinery activities or large-scale fermentation. Second, the carbon dioxide-rich gas is pressurized and refrigerated until it liquifies. Next, the pressure is reduced. When this occurs some liquid carbon dioxide vaporizes, causing a rapid lowering of temperature of the remaining liquid. As a result, the extreme cold causes the liquid to solidify into a snow-like consistency. Finally, the snow-like solid carbon dioxide is compressed into small pellets or larger blocks of dry ice.
A teaching laboratory demonstration for the production of dry ice is to use a 15 lb aluminum carbon dioxide fire extinguisher with a porous fabric collecting bag over the nozzle. The Joule-Thomson expansion of the gas lowers the temperature enough to produce an approximate 50/50 mixture of CO2 gas and dry ice snow also called dust that is collected in the bag. This is an inefficient process, and unsuitable for even lab-scale production. The expansion is inefficient, fire extinguishers are an expensive way to buy carbon dioxide, especially when a signed and dated fire extinguisher certification is required. Buying CO2 in fire extinguishers, however, is no more expensive than buying CO2 in cylinders and has the added advantage of demonstrating Newton's Three Laws of Motion with a wheeled chair and increases fire safety in a laboratory when refilled promptly after use.
Dry ice is typically produced in three standard forms: large blocks, cylindrical small (5/8 or 1/2 inch diameter) pellets and cylindrical tiny (1/8 inch diameter), high surface to volume pellets that float on oil or water and do not stick to skin because of their high radii of curvature. Tiny dry ice pellets are used primarily for ice blasting, quick freezing, fire fighting, oil solidifying and have been found to be safe for experimentation by middle school students wearing appropriate Personal Protective Equipment such as gloves and safety glasses. A standard block weighing approximately 30 kg covered in a taped paper wrapping is most common. These are commonly used in shipping, because they sublime relatively slowly due to a low ratio of surface area to volume. Pellets are around 1 cm (0.4 in) in diameter and can be bagged easily. This form is suited to small scale use, for example at grocery stores and laboratories where it is stored in a thickly insulated chest.
Dry ice can be used to arrest and prevent insect activity in closed containers of grains and grain products, as it displaces oxygen, but does not alter the taste or quality of foods. For the same reason, it can prevent or retard food oils and fats from becoming rancid.
When dry ice is placed in water, sublimation is accelerated, and low-sinking, dense clouds of smoke-like fog are created. This is used in fog machines, at theaters, haunted house attractions, and nightclubs for dramatic effects. Unlike most artificial fog machines, in which fog rises like smoke, fog from dry ice hovers near the ground. Dry ice is useful in theater productions that require dense fog effects. The fog originates from the bulk water into which the dry ice is placed, and not from atmospheric water vapor (as is commonly assumed).
It is occasionally used to freeze and remove warts. However, liquid nitrogen performs better in this role, since it is colder so requires less time to act, and less pressure. Dry ice has fewer problems with storage, since it can be generated from compressed carbon dioxide gas as needed.
Plumbers use equipment that forces pressurised liquid CO2 into a jacket around a pipe. The dry ice formed causes the water to freeze, forming an ice plug, allowing them to perform repairs without turning off the water mains. This technique can be used on pipes up to 4 inches (100 mm) in diameter.Dry ice can be used as bait to trap mosquitoes, bedbugs, and other insects, due to their attraction to carbon dioxide. Tiny dry ice pellets can be used to fight fire by both cooling fuel and suffocating the fire by excluding oxygen.
Industrial Dry ice blasting used for cleaning a rubber mold
Dry ice can be used for loosening asphalt floor tiles or car sound deadening material making it easy to prise off, as well as freezing water in valveless pipes to enable repair.
One of the largest mechanical uses of dry ice is blast cleaning. Dry ice pellets are shot from a nozzle with compressed air, combining the power of the speed of the pellets with the action of the sublimation. This can remove residues from industrial equipment. Examples of materials removed include ink, glue, oil, paint, mold and rubber. Dry ice blasting can replace sandblasting, steam blasting, water blasting or solvent blasting. The primary environmental residue of dry ice blasting is the sublimed CO2, thus making it a useful technique where residues from other blasting techniques are undesirable. Recently, blast cleaning has been introduced as a method of removing smoke damage from structures after fires.
Dry ice is also useful for the de-gassing of flammable vapours from storage tanks — the sublimation of dry ice pellets inside an emptied and vented tank causes an outrush of CO2 that carries with it the flammable vapours.
The removal and fitting of cylinder liners in large engines requires the use of dry ice to chill and thus shrink the liner so that it freely slides into the engine block. When the liner then warms up, it expands, and the resulting interference fit holds it tightly in place. Similar procedures may be used in fabricating mechanical assemblies with a high resultant strength, replacing the need for pins, keys or welds.
The process of altering cloud precipitation can be done with the use of dry ice. It was widely used in experiments in the US in the 1950s and early 60s before it was replaced by silver iodide. Dry ice has the advantage of being relatively cheap and completely non-toxic. Its main drawback is the need to be delivered directly into the supercooled region of clouds being seeded.
A "dry ice bomb" is a balloon-like device using dry ice in a sealed container such as a plastic bottle. Water is usually added to accelerate the sublimation of the dry ice. As the dry ice sublimes, pressure increases, causing the bottle to burst causing a loud noise that can be avoided when a #3 rubber stopper replaces the screw on cap to make a Water rocket with a Two-liter bottle.
Following the Mars flyby of the Mariner 4 spacecraft in 1966, scientists concluded that Mars' polar caps consist entirely of dry ice. However, findings made in 2003 by researchers at the California Institute of Technology have shown that Mars' polar caps are almost completely made of water ice, and that dry ice only forms a thin surface layer that thickens and thins seasonally. A phenomenon named dry ice storms was proposed to occur over the polar regions of Mars. They are comparable to Earth's thunderstorms, with crystalline CO2 taking the place of water in the clouds.
In 2012, the European Space Agency's Venus Express probe detected a cold layer in the atmosphere of Venus where temperatures are close to the triple point of carbon dioxide and it is possible that flakes of dry ice precipitate.
Prolonged exposure to dry ice can cause severe skin damage through frostbite, and the fog produced may also hinder attempts to withdraw from contact in a safe manner. Because it sublimes into large quantities of carbon dioxide gas, which could pose a danger of hypercapnia, dry ice should only be exposed to open air in a well-ventilated environment. For this reason, dry ice is assigned the S-phraseS9 in the context of laboratory safety. Industrial dry ice may contain contaminants that make it unsafe for direct contact with foodstuffs. Tiny dry ice pellets used in dry ice blast cleaning do not contain oily residues.
Although dry ice is not classified as a dangerous substance by the European Union, or as a hazardous material by the United States Department of Transportation for ground transportation, when shipped by air or water, it is regulated as a dangerous good and IATA packing instruction 954 (IATA PI 954) requires that it be labeled specially, including a diamond-shaped black-and white label, UN 1845. Also, arrangements must be in place to ensure adequate ventilation so that pressure build-up does not rupture the packaging. The Federal Aviation Administration in the US allows airline passengers to carry up to 2.5 kg per person either as checked baggage or carry-on baggage, when used to refrigerate perishables.
The Bulletin des Lois du Royaume de France (Bulletin of the laws of the kingdom of France), 9th series, part ii, no. 92, page 74 (February 1832) lists: "24° M. Thilorier (Adrien-Jean-Pierre) employé à l'administration des postes, demeurant à Paris, place Vendôme, no 21, auquel il a été délivré le 16 mai dernier, le certificat de sa demande d'un brevet d'invention de dix ans pour le perfectionnement d'une machine à comprimer le gaz; …" (24th Mr. Thilorier (Adrien-Jean-Pierre) employed at the Post Office, residing in Paris, Place Vendôme, no. 21, where was delivered May 16th last, the certificate, by his request, for a patent of invention for ten years for the improvement of a machine to compress gas; … )
In a patent (no. 2896) which was filed on May 16, 1831 and which was published in 1836, Adrien-Jean-Pierre Thilorier, an employee of the French "Administration des postes" (i.e., Post Office) in Paris is identified explicitly as the inventor of a machine for compressing gases which in 1829 won the French Academy of Sciences' Montyon prize for mechanics. The patent describes the machine and its performance in detail. See: (French Ministry of Commerce), "Pour le perfectionnement d'une machine à comprimer le gaz, …" (For the improvement of a machine to compress gas, …), Description des Machines et Procédés consignés dans les brevets d'invention, … , 30 : 251–267 (1836).
^Reisen WK, Boyce K, Cummings RC, Delgado O, Gutierrez A, Meyer RP, Scott TW (1999). "Comparative effectiveness of three adult mosquito sampling methods in habitats representative of four different biomes of California". J Am Mosq Control Assoc. 15 (1): 24–31. PMID10342265.
^"Could a Freeze Gun Put Flames on Ice" by Zantos Peabody Los Angeles Times local section B3 9/3/2002