Miért van hamutartó a repülőn?

Hazafelé ezt fotóztam az egyik legújabb típusú repülőgépen, az Airbus A380-ason a WC-ben:

Igen, hamutartó. Az Airbus A380 2007-ben repült először menetrend szerint (Singapore Airlines), a legtöbb légitársaság már a 90-es években betiltotta a dohányzást az összes járatán, 2002 óta még az Aeroflot-on sem lehet dohányozni, minek akkor a hamutartó és az állandóan világító dohányzást tiltó jelzések? Hány bedugva felejtett telefontöltő áramfogyasztásával egyenértékű az összes repülőn világító lámpasor?
Persze nem nekem jutott eszembe, már 2007-ben megkérdezték a Singapore Airlines elnökét, hogy mégis minek a hamutartó a zsírúj A380-ason, mire azt mondta, benne van az FAA szabályzatban. Meg is találtam a 23-as részben (Federal Aviation Regulations Part 23, Airworthiness Standards : Normal, Utility, Acrobatic and Comuter Category Airplanes) a 272-ik oldalon, a 23.853 paragrafusban:
"§ 23.853 Passenger and crew compartment
interiors.
For each compartment to be used by
the crew or passengers:
(a) The materials must be at least
flame-resistant;
(b) [Reserved]
(c) If smoking is to be prohibited,
there must be a placard so stating, and
if smoking is to be allowed—
(1) There must be an adequate number
of self-contained, removable ashtrays;
and
(2) Where the crew compartment is
separated from the passenger compartment,
there must be at least one illuminated
sign (using either letters or
symbols) notifying all passengers when
smoking is prohibited. Signs which notify
when smoking is prohibited must—
(i) When illuminated, be legible to
each passenger seated in the passenger
cabin under all probable lighting conditions;
and
(ii) Be so constructed that the crew
can turn the illumination on and off;
and
(d) In addition, for commuter category
airplanes the following requirements
apply:
(1) Each disposal receptacle for towels,
paper, or waste must be fully enclosed
and constructed of at least fire
resistant materials and must contain
fires likely to occur in it under normal
use. The ability of the disposal receptacle
to contain those fires under all
probable conditions of wear, misalignment,
and ventilation expected in service
must be demonstrated by test. A
placard containing the legible words
‘‘No Cigarette Disposal’’ must be located
on or near each disposal receptacle
door.
(2) Lavatories must have ‘‘No Smoking’’
or ‘‘No Smoking in Lavatory’’ placards
located conspicuously on each side
of the entry door and self-contained,
removable ashtrays located conspicuously
on or near the entry side of each
lavatory door, except that one ashtray
may serve more than one lavatory door
if it can be seen from the cabin side of
each lavatory door served. The placards
must have red letters at least 1⁄2
inch high on a white background at
least 1 inch high (a ‘‘No Smoking’’ symbol
may be included on the placard)."