In , Jeff Liebermann wrote
in part:

Neon lamp needs about 60 volts to light and 40 volts to stay lit. The
4 watt flourescent tube wants at least 90 volts to start, and I think
(i.e. guess) about 50 volts to stay lit.

Lower voltage neon lamps do indeed light at 60 volts RMS and stay lit at
40 volts RMS. But these are lowish figures.

4-watt fluorescents need more, except they stay lit at only about 30
volts at full current, and part of that reason is thermionic emission from
hot electrodes.

I would not worry about RF from a cellphone igniting anything. If a
cellphone is going to be found to ignite gasoline vapor, I think more
likely ways a

* Sparks in the vibration motor
* Sparks from failing wires/connections
* Sparks in speakers with voice coils with intermittent shorts
* Sparks in switches (in whatever few models having switches that
actually switch enough current to make a spark)

I have already seen the Snopes item months ago when I first heard of
cellphones supposedly causing gas station fires, and they make it sound
as if cellphone ignition of gasoline vapors may never have actually
occurred, evidence that this has indeed happened appears mainly anecdotal,
and that this is rare if it does happen.

When I refuel my car, I keep my cellphone either far or upwind from the
gas inlet of my car. (My cellphone has vibration on.) I also ground
myself by touching something far/upwind of the fuel inlet if I let go of
the nozzle and have to touch the nozzle or anything near the fuel inlet
again before leaving the gas station to avoid the greater danger of static
electricity.

- Don Klipstein )