Antifreeze in the context of "Ethylene glycol poisoning"

Ethylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula (CH₂OH)₂. It is mainly used for two purposes: as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odorless, colorless, flammable, viscous liquid. It has a sweet taste but is toxic in high concentrations. This molecule has been observed in outer space.

In fluid thermodynamics, a heat transfer fluid (HTF) is a gas or liquid that takes part in heat transfer by serving as an intermediary in cooling on one side of a process, transporting and storing thermal energy, and heating on another side of a process. Heat transfer fluids are used in countless applications and industrial processes requiring heating or cooling, typically in a closed circuit and in continuous cycles. Cooling water, for instance, cools an engine, while heating water in a hydronic heating system heats the radiator in a room.

Water is the most common heat transfer fluid because of its economy, high heat capacity and favorable transport properties. However, the useful temperature range is restricted by freezing below 0 °C and boiling at elevated temperatures depending on the system pressure. Antifreeze additives can alleviate the freezing problem to some extent. However, many other heat transfer fluids have been developed and used in a huge variety of applications. For higher temperatures, oil or synthetic hydrocarbon- or silicone-based fluids offer lower vapor pressure. Molten salts and molten metals can be used for transferring and storing heat at temperatures above 300 to 400 °C where organic fluids start to decompose. Gases such as water vapor, nitrogen, argon, helium and hydrogen have been used as heat transfer fluids where liquids are not suitable. For gases the pressure typically needs to be elevated to facilitate higher flow rates with low pumping power.

Household hazardous waste (HHW) was a term coined by Dave Galvin from Seattle, Washington in 1982 as part of the fulfillment of a US EPA grant. This new term was reflective of the recent passage of the Resource Conservation and Recovery Act of 1976 (RCRA 1976) in the US. This act and subsequent regulations strengthened the environmental protection requirements for landfills, in Subpart D, and created a "cradle to grave" management system for hazardous wastes, in Subpart C. From RCRA 1976 the US EPA promulgated rules in 1980 which explicitly excluded any wastes from household origins from regulation as a hazardous waste at the federal level. Most US states adopted parallel regulations to RCRA 1976 but were allowed to be more stringent. California took advantage of this allowance and chose to not exempt household origin wastes from their state hazardous waste laws. HHW products exhibit many of the same dangerous characteristics as fully regulated hazardous waste which are their potential for reactivity, ignitability, corrosivity, toxicity, or persistence. Examples include drain cleaners, oil paint, motor oil, antifreeze, fuel, poisons, pesticides, herbicides and rodenticides, fluorescent lamps, lamp ballasts containing PCBs, some smoke detectors, and in some states, consumer electronics (such as televisions, computers, and cell phones). Except for California, most states exclude HHW from their hazardous waste regulations and regulate the management of HHW largely under their solid waste regulatory schemes.

Certain items such as batteries and fluorescent lamps can be returned to retail stores for disposal. The Call2Recycle maintains a list of battery recycling locations and your local environmental organization should have list of fluorescent lamp recycling locations. The classification "household hazardous waste" has been used for decades and does not accurately reflect the larger group of materials that during the past several years have become known as "household hazardous wastes". These include items such as latex paint, non-hazardous household products and other items that do not generally exhibit hazardous characteristics which are routinely included in "household hazardous waste" disposal programs. The term "home generated special materials" more accurately identifies a broader range of items that public agencies are targeting as recyclable and/or should not be disposed of into a landfill.

Denatonium, usually available as denatonium benzoate (under trade names such as Denatrol, BITTERANT-b, BITTER+PLUS, Bitrex, Bitrix, and Aversion) and as denatonium saccharinate (BITTERANT-s), is the bitterest chemical compound known, with bitterness thresholds of 0.05 ppm for the benzoate and 0.01 ppm for the saccharinate. It was discovered in 1958 during research on local anesthetics by T. & H. Smith of Edinburgh, Scotland, and registered under the trademark Bitrex.

Dilutions of as little as 10 ppm are unbearably bitter to most people. Denatonium salts are usually colorless and odorless solids, but are often traded as solutions. They are used as aversive agents (bitterants) to prevent inappropriate ingestion. Denatonium is used in denatured alcohol, antifreeze, preventive nail biting preparations, respirator mask fit-testing, animal repellents, liquid soaps, shampoos, and Nintendo Switch game cards to prevent accidental swallowing or choking by children. It is not known to pose any long-term health risks.

A cryoprotectant is a substance used to protect biological tissue from freezing damage (i.e. that due to ice formation). Arctic and Antarctic insects, fish and amphibians create cryoprotectants (antifreeze compounds and antifreeze proteins) in their bodies to minimize freezing damage during cold winter periods. Cryoprotectants are also used to preserve living materials in the study of biology and to preserve food products.

For years, glycerol has been used in cryobiology as a cryoprotectant for blood cells and bull sperm, allowing storage in liquid nitrogen at temperatures around −196 °C. However, glycerol cannot be used to protect whole organs from damage. Instead, many biotechnology companies are researching the development of other cryoprotectants more suitable for such uses. A successful discovery may eventually make possible the bulk cryogenic storage (or "banking") of transplantable human and xenobiotic organs. A substantial step in that direction has already occurred. Twenty-First Century Medicine has vitrified a rabbit kidney to −135 °C with their proprietary vitrification cocktail. Upon rewarming, the kidney was successfully transplanted into a rabbit, with complete functionality and viability, able to sustain the rabbit indefinitely as the sole functioning kidney.