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Note added at 15 mins (2007-09-15 14:05:10 GMT)
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Or Expiry Date

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Note added at 16 mins (2007-09-15 14:06:34 GMT)
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http://patents1.ic.gc.ca/claims?patent_number=1250367&langua...

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Note added at 16 mins (2007-09-15 14:07:00 GMT)
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http://www.eric.ed.gov/ERICWebPortal/custom/portlets/recordD...

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Note added at 17 mins (2007-09-15 14:08:02 GMT)
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The term is originally used for humans, but in some instances, like in the links provided, it is used for objects.

The link below explains it clearly.

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Note added at 1 hr (2007-09-15 15:11:26 GMT)
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Sorry the owrd is expected!

May be as it is a consumable item we could say self life instead

The expected useable life time of a butane gas cylinder is refred to it in Egyptian standard specifications

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Note added at 8 hrs (2007-09-15 22:41:53 GMT)
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I see it like that here as long it is going with use time
The expected useable life time of a butane gas cylinder is referred to it in The Egyptian standard specifications


sorry for typo in the top phrase

a guess

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Note added at 12 hrs (2007-09-16 01:55:44 GMT)
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# The maximum lifespan of a species is the characteristic observed age of death for its very oldest individual(s) (eg, for humans 122+ years). On the other hand, average lifespan is the age at which 50 percent of the members of a species or group has died. Over the last two centuries, average life expectancy has risen significantly, while maximum lifespan as demonstrated in the Table above has hardly changed at all.
images.antiagingconference.com/files/1103/aagateway/glossaryofterms.asp

# Lifespans are thought to be genetically determined - based on the longevity differences of species, mutants, hybrids, strains and sexes. Because of improved medical and social conditions the average human life expectancy at birth has increased from 40 years in the mid 19th century to over 75 years today. (For a C19th Labourer in rural England it was 38 years, but just 29 years in London's Whitechapel slums.)
www.embassy.org.nz/encycl/l3encyc.htm

# life: the period during which something is functional (as between birth and death); "the battery had a short life"; "he lived a long and happy life"
wordnet.princeton.edu/perl/webwn

# Life expectancy is the most likely number of years remaining for a living being (or the average for a class of living beings) of a given age to live.
en.wikipedia.org/wiki/Lifespan

It is hypothetical because it is assumed upon manufacturing the material and it is not exact expiry date, may be after may be before the hypothetical lifetime.