Carbon monoxide is a gas, just like

Carbon monoxide is a gas, just like
oxygen or nitrogen or carbon dioxide.

It's produced when any fuel
that contains carbon,

including gas we burn at home,

or biomass, or biofuel,
as we call it nowadays,

or coal or oil,

any of those that burns
without enough oxygen present,

what happens is the carbon in the fuel
combines with oxygen in the air

to produce carbon monoxide,
which is very toxic and dangerous.

If there was more oxygen
it would form carbon dioxide,

two oxygen atoms to one carbon, which is
not toxic in the way carbon monoxide is.

So it's a toxic gas produced by anything
that burns when it burns poorly.

So carbon monoxide effectively
stops you taking up oxygen.

So to say it chokes you doesn't sound
quite right, but it has the same effect.

It reduces the oxygen available
to the heart and brain

and that's what kills you.

We must think in terms of how much
carbon monoxide we're worrying about.

Let's think about the sort of levels
we're likely to find in people's houses.

At those levels, they're likely
to be pretty low, in actual fact.

And so what will it produce?
Headaches; people feel sick or nauseous;

they feel very tired;
they tend to drop off to sleep;

they lose concentration;
they become confused.

And you see already the danger,

because as those symptoms creep up
on you, the confusion increases,

and your ability to do something
about it declines.

And so the classic example
of someone going to bed in a room

with a source of carbon monoxide,

which might be an un-flued gas fire
not working properly,

or a blocked chimney
with a fire in the grate,

then they fall asleep and don't
notice that they're being poisoned.

And that's what kills them.
At much higher concentrations,

people collapse almost at once
and die very quickly.

But at the sort of concentrations
we are thinking about in the UK,

then although they can be dangerous,

the symptoms and signs
tend to creep up on you.

Battery-operated alarms,
which you could call mobile alarms,

that detect carbon monoxide,
can be very useful

if you're going away from home
in a caravan or a camper or a trailer.

Any appliance that burns indoors

should be checked regularly
by a qualified engineer.

There are four things to remember

about preventing poisoning
from carbon monoxide.

They are: (1) Chimneys and flues
should be clean and working well.

(2) Rooms should be well ventilated.

(3) All devices that burn fossil fuels,
for example, gas, oil or coke,

should be serviced regularly
by competent engineers.

(4) A carbon monoxide alarm is
a useful thing that may save your life,

but it is not, repeat not, a substitute
for having devices serviced properly.