Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: geordief on 23/01/2011 12:31:45

Title: Does burning laurel logs release cyanide?
Post by: geordief on 23/01/2011 12:31:45
Apparently it is the cyanide in green laurel that is toxic and some say not to burn it in an open fire.
But are small doses of cyanide gas really harmful?
If the room is well ventilated  and you do not stay around if the room becomes smokey  at all and assuming that you do not use laurel logs as a mainstay , how much of a risk would be involved?
Am I right in thinking that you would also be warned of any amount of cyanide gas in the air by  a noticeable odour?
Title: Re: Does burning laurel logs release cyanide?
Post by: CliffordK on 23/01/2011 13:39:45
Hmmm.
I was going to use Laurel for a BBQ.  Perhaps I'll have to re-think that  [xx(]

There seems to be lots of notes that burning biomass will release Cyanide, but that it has an atmospheric lifespan of only 2-4 months, perhaps absorbed into the ocean, and broken down there.

If you are burning anything indoors, make sure you have a good stove or fireplace, and that it drafts up the chimney.  For occasional burning with a well ventilated system, it shouldn't be a problem.  However, it probably wouldn't be advisable if an entire community chose to burn large amounts of it.

You should never burn any fire in an enclosed space without adequate ventilation.  Not only is there Cyanide risk from multiple materials, there is also risk of carbon monoxide poisoning, and perhaps other toxins.
Title: Re: Does burning laurel logs release cyanide?
Post by: geordief on 23/01/2011 14:58:35
thanks
are you sure you aren't confusing bay leaves (Laurus nobilis,) with laurel leaves? I would have thought bay leaves might work well on  a bbq.Perhaps that is what you were thinking of doing.
I think they are really  oily and also might impart a nice flavour as well as being quite spectacular.
Title: Re: Does burning laurel logs release cyanide?
Post by: Bored chemist on 23/01/2011 18:24:59
"Am I right in thinking that you would also be warned of any amount of cyanide gas in the air by  a noticeable odour?"

No.
On the other hand, cyanides are flammable so not much will escape from a fire unless the access of air is restricted.
Title: Re: Does burning laurel logs release cyanide?
Post by: CliffordK on 23/01/2011 22:57:23
On the other hand, cyanides are flammable so not much will escape from a fire unless the access of air is restricted.
I was wondering about that...  However, there are lots of notes about Cyanide being released with burning of synthetics (plastics, rubbers), as well as burning biomass. 

Perhaps the amounts would be minimized with a good, hot burning modern wood stove.
Title: Re: Does burning laurel logs release cyanide?
Post by: Bored chemist on 24/01/2011 20:48:09
With adequate air supplied to the fire and proper ventilation, the cyanide wouldn't be a problem. If you don't have enough air and ventilation then, whatever sort of wood you are burning, the carbon monoxide will kill you.
Title: Does burning laurel logs release cyanide?
Post by: chris on 05/02/2011 10:51:37
Laurel burns beautifully, and hot; I pruned a laurel hedge a few years back and we've been burning the results in the log-burner recently. The flames are an interesting blue colour, presumably alcohols and other volatiles released by the cooking.


Regarding biomass burning and cyanide, scientists used the cyanide signal last year to find worrying signs that the Monsoon sends Asia's pollution skywards, bypassing the normal cleansing mechanisms that remove certain contaminants before the air goes upwards.

http://www.thenakedscientists.com/HTML/content/news/news/1931/

Chris