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halon

halon

3 9.9
Gases used in fire extinguishers that harm the ozone layer
  • noun
  • /ˈheɪlɒn/
  • Specialized
: halón
  • The shuttles are equipped with handheld fire extinguishers, an automatic foam-spray system that suppresses fires beneath the vehicle, and a halon gas system that begins operating if a fire survives the first two attempts to extinguish it.
  • halons used in fire
  • CFCs and halons

Examples

  • Murphy sprays a cloud of halon, and the fire dims, but only for a moment.

    Fiction book (2002)
  • The canister drops into the flames from above, suddenly venting a hissing cloud of halon gas.

    Fiction book (2000)
  • The fire set off the halon system.

  • A fine layer of halon powder lies over everything, but the fire is out.

    Fiction book (2002)
  • The halon gun is on the catwalk.

  • They triggered the halon gas system.

  • Water does not really help preserve documents in a fire; halon is standard for document warehousing.

    Blog text (12)
  • Murphy looks down to see his pant leg is on fire, as Dodge turns a cloud of halon on him, putting it out.

    Fiction book (2002)
  • The fire activated the automatic Halon fire protection and emergency fuel shutdown systems, extinguishing it.

    Academic text (1998)
  • The canister drops into the flames from above, suddenly venting a hissing cloud of halon gas.

Synonyms

halocarbon
vshalon
  • Specialized
1 8.2

A chemical made of carbon joined with elements like fluorine or chlorine

is a narrower group focusing on alkane-derived, bromine-rich firefighting chemicals
alkyl halide
vshalon
  • Specialized
6.9

A chemical made when one hydrogen in an alkane is replaced by a halogen

is a bromine-containing subtype often used in fire extinguishers
haloalkane
vshalon
  • Specialized
9.9

A chemical made when hydrogen atoms in a simple carbon chain are replaced by chlorine or bromine

is often the brominated form used in firefighting and harms ozone

Surface Forms

halon singular
halons plural

Morphology

halon = halo (opaque) = halo + on

The word is a specialised chemical term formed from the combining form 'halo-' plus the technical suffix '-on'; its meaning as a class of fire-suppressant compounds is unlikely to be inferable by an average B1 learner from the everyday word 'halo'.

Etymology

Halon comes from the chemical prefix halo-, from a Greek word for 'salt' that chemists use for elements like chlorine and bromine. So halon is a compound that contains those 'halogen' elements and was used as a gas in fire extinguishers, but many halons were later limited because they damage the ozone.