¿Qué gas hay en los congeladores?¿es inocuo?

Answer 1

Se utilizan Freones (compuestos fluoro Cloro carbonados) y no son inocuos, tanto resultan toxicos a ciertas dosis, como son destructores de la capa de ozono (molecula triatomica de oxigeno)

Answer 2

Carbon tetrachloride was used in fire extinguishers and glass "anti-fire grenades" from the late nineteenth century until around the end of World War II. Experimentation with chloroalkanes for fire suppression on military aircraft began at least as early as the 1920s.

American engineer Thomas Midgley developed Chlorofluorocarbons (CFC) in 1928 as a replacement for ammonia (NH3), chloromethane (CH3Cl), and sulfur dioxide (SO2) that are toxic but in common use at the time as refrigerants. The new compound developed had to have a low boiling point, be non-toxic and be generally non-reactive. In a demonstration for the American Chemical Society, Midgley flamboyantly demonstrated all these properties by inhaling a breath of the gas and using it to blow out a candle.

Midgley specifically developed CCl2F2. However, one of the attractive features is that there exists a whole family of the compounds, each having a unique boiling point which can suit different applications. In addition to their original application as refrigerants, chlorofluoroalkanes have been used as propellants in aerosol cans, cleaning solvents for circuit boards and as blowing agents for making expanded plastics (such as the expanded polystyrene used in packaging materials and disposable coffee cups).

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Development of alternatives
During World War II various early chloroalkanes were in standard use in military aircraft by some combatants, but these early halons suffered from excessive toxicity. Nevertheless after the war they slowly became more common in civil aviation as well.

In the 1960s, fluoroalkanes and bromofluoroalkanes became available and were quickly recognized as one of the most effective fire-fighting materials discovered. Much early research with Halon 1301 was conducted under the auspices of the US Armed Forces, while Halon 1211 was, initially, mainly developed in the UK. By the late 1960s they were standard in many applications where water and dry-powder extinguishers posed a threat of damage to the protected property, including computer rooms, telecommunications switches, laboratories, museums and art collections. Beginning with warships, in the 1970s, bromofluoroalkanes also progressively came to be associated with rapid knockdown of severe fires in confined spaces with minimal risk to personnel.

Work on alternatives for chlorofluorocarbons in refrigerants began in the late 1970s after the first warnings of damage to stratospheric ozone were published in the journal Nature in 1974 by Molina and Rowland (who shared the 1995 Nobel Prize for Chemistry for their work). Adding hydrogen and thus creating hydrochlorofluorocarbons (HCFC), chemists made the compound less stable in the lower atmosphere enabling it to break down before reaching the ozone layer. Later alternatives dispense with the chlorine, creating hydrofluorocarbons (HFC) with even shorter lifetimes in the lower atmosphere.

By the early 1980s, bromofluoroalkanes were in common use on aircraft, ships and large vehicles as well as in computer facilities and galleries. However, concern was beginning to be felt about the impact of chloroalkanes and bromoalkanes on the ozone layer. The Vienna Convention on Ozone Layer Protection did not cover bromofluoroalkanes as it was thought, at the time, that emergency discharge of extinguishing systems was too small in volume to produce a significant impact, and too important to human safety for restriction.

However, by the time of the Montreal Protocol it was realised that deliberate and accidental discharges during system tests and maintenance accounted for substantially larger volumes than emergency discharges, consequently halons were brought into the treaty but with many exceptions.

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Phase out
Use of certain chloroalkanes as solvents for large scale application, such as dry cleaning, have been phased out, for example, by the IPPC directive on greenhouse gases in 1994 and by the Volatile Organic Compounds (VOC) directive of the EU in 1997. Permitted chlorofluoroalkane uses are medicinal only.

Finally, bromofluoroalkanes have been largely phased out and the possession of such equipment is prohibited in some countries like the Netherlands and Belgium, from 1 January 2004, based on the Montreal Protocol and guidelines of the European Union.

Production of new stocks ceased in most (probably all) countries as of 1994. However many countries still require aircraft to be fitted with halon fire suppression systems because no safe and completely satisfactory alternative has been discovered for this application. There are also a few other, highly specialised, uses. These programs recycle halon through "halon banks" coordinated by the Halon Recycling Corporation[1] to ensure that discharge to the atmosphere occurs only in a genuine emergency and to conserve remaining stocks.

Answer 3

Si no me equivoco se están emplenado los refrigeranates con denominación R, como el R14 ó el R134, pero desconozco sus propiedades.

Answer 4

Antes se usaba el freón, ahora se usan otros pero no son inocuos el respirarlos puede causar daños y es probable que en concentraciones altas incluso la muerte

Answer 5

Era el freon pero se ha dejado de usar por que destruye la capa de ozono aun que era inocuo para la salud e incluso se usaba en los aerosoles.

Desconozco cual se esté usando actualmente pero por regulación internacional debe ser inocuo.

A principios del siglo veinte, en las fábricas de hielo, se usaba amoniaco, pero precisamente, por no ser inocuo, se prohibió para ese efecto.

Answer 6

Gas freón, no es inocuo, salvo que esté en concentraciones adecuadas

Answer 7

freon, no es inocuo