Dry ice

[whitehousejamie]

Hi All,

 

I am considering utilising dry ice for an event using a Pea Souper and locally sourced dry ice pellets.

 

I am aware of the dangers in the preparation, storage, handling, boiling hot water etc but can anyone please give me advice regarding the risk to, for example a small child who might breathe in the gas during use.

 

I have used low fog (chilled smoke) units previously but the effect is ruined as soon as people walk through it.

 

Any advice greatly appreciated.

 

Thank you.

[Ynot]

Breathing the gas in small quantities is not a major risk.

 

As with most things, extended exposure MAY cause respiratory problems, and in SOME people the excess of CO2 MAY cause problems, but it's all about moderation.

 

The simple fact that dry ice will hug the floor by design means that it's well out of the way of even the smallest child if they're standing.

 

I've seen shows where performers start laid down on stage and are then covered in a sea of ice (eg the BRB Nutcracker, start of act 2 where the rats are all lying on the deck as the bird flys above them). As long as the performers exercise a sensible breathing regime there shouldn't be a major issue with short term exposure.

 

 

 

But in the end you need to assess the risks accordingly as pertaining to your own situation,.

[ImagineerTom]

Breathing the gas in small quantities is not a major risk.

erm breathing in the gas is a significant risk - I challenge you to take 2 breaths of CO2 gas and not fall over or display any of the often fatal side effects of asphyxiation...

That said in normal use the risk is low simply because it hugs the floor and most people don't breath from the floor but you do need to be aware of the gas "pooling" in any low points for example. The "solution" to 99% of the risks of the gas is simply good ventilation so it's fairly easy to address.

[paulears]

I would strongly disagree. Nobody would try to breath CO2 in any concentration likely to cause harm. Scaremongering! Stage techs waggling a pea soupier handle often vanish in the fog, and show no signs of fatal asphyxiation. Orchestra pits fill up with it, and all the stories of musicians keeling over are to the best of my knowledge apocryphal. After all, if somebody hyperventilates, you get them to breath from a paper bag, increasing the ratio of CO2 in the air - the danger of CO2 is simply that in high concentrations it displaces the oxygen and the first symptom is light headedness.

 

You cannot have good ventilation, or the effect disperses. You can vanish in the fog and have no symptoms at all, while other people are more susceptible to it because of reduced lung capacity or illness.

 

The usual advice is to avoid breathing in the fog, which is sensible - but on my risk assessments, CO2 inhalation is deemed low risk - dealing with the stuff from a practical perspective is much more troublesome - storage, deliveries, safety gloves and exclusion zones make it an annoyance. It's still, however, great fog!

[ImagineerTom]

Being pedantic here, the original claim was "Breathing the gas..... isn't a major risk" - the white smokey stuff that "dry ice" produces is a mixture of CO2 gas & water vapour that becomes increasingly dilute with "air" the longer it is in existence.

 

The risk from breathing in the white smokey stuff is low, the risk from breathing in CO2 gas is high. The OP was asking for info and it's important he's aware of the full picture not just a tiny snippet of information which doesn't paint the broader picture.

 

As I said, it's perfectly usable (and commonly used) and to be honest the most likely risks are associated with storage and handling rather than asphyxiation related since in common use by the time its reached a gas stage its being diluted with ambient air.

[Ynot]

Breathing the gas in small quantities is not a major risk.

Hmmm....

OK - maybe I mis-typed a little here - possibly a better way of phrasing that should have been "Breathing the gas in low concentration is not a major risk" but reading back I think the rest of my post bears that aspect up nicely.

[matt_beal]

The only risk of asphyxia is if the CO2 is so concentrated that there isn't enough oxygen in the air to breath in. The most the CO2 will do in the short term is increase your respiratory drive, making you breath faster in order to remove more CO2 from your circulation.

 

FWIW Hyperventilation just means breathing too fast. If you breath too fast (because of a panic attack), you drop the level of CO2 in the blood as you are breathing more CO2 out. The low levels of CO2 are what make you feel unwell, so the paper bag increases the amount of CO2 being breathed in, normalising the levels and hopefully making you feel better.

 

That's the physiology anyway, I've never had to use or risk assess the use of dry ice :)

 

Matt

[paulears]

My grumpiness is just the use of very emotive words - significant risk - fatal side effects of asphyxiation...

 

I cannot find any deaths due to theatrical use of CO2, and while hot water, slippery stages, storage and handling have a risk worth paying attention to, the actual CO2 itself is inert. I had two glaciators that were very unreliable, and each one was swapped out, and were just unpredictable. The addition of two peasoupers made the effect for me - and fully worth the hassle. Risk wise - in similar fog levels, would you rather breath in an inert gas, or liquid with safe chemicals in?

[Brian]

We've done the whole CO2 levels thing before and I, amongst others, pointed out just how much CO2 you need in your typical venue before it becomes an issue.

[alistermorton]

My grumpiness is just the use of very emotive words - significant risk - fatal side effects of asphyxiation...

 

I cannot find any deaths due to theatrical use of CO2, and while hot water, slippery stages, storage and handling have a risk worth paying attention to, the actual CO2 itself is inert. I had two glaciators that were very unreliable, and each one was swapped out, and were just unpredictable. The addition of two peasoupers made the effect for me - and fully worth the hassle. Risk wise - in similar fog levels, would you rather breath in an inert gas, or liquid with safe chemicals in?

 

Small point of pedantry - carbon dioxide is not an inert gas. Magnesium burns extremely well in CO2, and while under "normal" conditions CO2 is a relatively stable and fairly unreactive gas, it's not inert.

[kerry davies]

This could be my fault for raising the hazards of CO2 jets in confined spaces on an earlier thread. Normal dry ice or fogger use is nowhere near as concentrated and poses minimal risk. Pumping the stuff into confined spaces from pressurised cylinders at high rates for more than brief periods, as used in clubs, needs consideration.

 

As Paul says the exhaled breath of a normal human is actually better for assisted breathing than ambient air hence the Kiss Of Life being better than compressed air.

[kalmatthew]

As Paul says the exhaled breath of a normal human is actually better for assisted breathing than ambient air hence the Kiss Of Life being better than compressed air.

 

This isnt quite right. The reason that the "kiss of life" is ideal is that it requires little or no equipment. The Gold standard for resuscitation involves Oxygen enriched air.

 

Ventilation

Provide artificial ventilation as soon as possible in any patient in whom spontaneous

ventilation is inadequate or absent. Expired air ventilation (rescue breathing) is effective

but the rescuer’s expired oxygen concentration is only 16-17%, so it must be replaced

as soon as possible by ventilation with oxygen-enriched air.

http://www.resus.org.uk/pages/guide.htm

[Nicktaylor]

Off topic, but bloody hell Matthew where have you resurfaced from! Guildford too far away! I need you in my part of the world again. Busy with various shows. It will only get worse as I get towards retirement from the day job!

 

My grumpiness is just the use of very emotive words - significant risk - fatal side effects of asphyxiation...

 

I cannot find any deaths due to theatrical use of CO2, and while hot water, slippery stages, storage and handling have a risk worth paying attention to, the actual CO2 itself is inert. I had two glaciators that were very unreliable, and each one was swapped out, and were just unpredictable. The addition of two peasoupers made the effect for me - and fully worth the hassle. Risk wise - in similar fog levels, would you rather breath in an inert gas, or liquid with safe chemicals in?

The point is Paul and I am not arguing with your sentiment, that there have been some prosecutions because of unsafe use of CO2 and it is only luck no one died because they had poor respiratory issues.

On this board we have professionals like your good self. Experience amateurs like myself and maybe a third area who have to ask the question, sometimes students or people who have never used the kit . I dont hire out my peassouper any more as I cant be bothered to be quoting H and S to people or find a supplier for frozen CO2. It does give the best effect available to amateurs, but its my insurance at risk!

[paulears]

I don't think insurance is an issue? There are plenty of insurance companies covering much more risky processes in our world.

 

This info sheet is worth a read.

 

I've not come across any prosecutions for theatre/events use of CO2 - and a quick Google returns nothing at all. I've no wish to prolong this, but there appears to be no substantive evidence that there's an active issue here?

[Nicktaylor]

I don't think insurance is an issue? There are plenty of insurance companies covering much more risky processes in our world.

 

This info sheet is worth a read.

 

I've not come across any prosecutions for theatre/events use of CO2 - and a quick Google returns nothing at all. I've no wish to prolong this, but there appears to be no substantive evidence that there's an active issue here?

 

In the back of my mind I thought an accident happened with an orchestra. the dry ice rolled off the stage into the lowest point and some of the band were hurt, I think HSE got involved that time