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andrewjb1  
#1 Posted : 29 March 2023 17:55:41(UTC)
Rank: Forum user
andrewjb1

We had a gas leak in the office and employees said they were feeling sick, we evacuated the building and did all the usual things like open windows etc however, one employee is pregnant, we have advised her to speak to her GP.

What should we do next, we will log the incident but is it RIDDOR reportable?

Kate  
#2 Posted : 30 March 2023 07:29:11(UTC)
Rank: Super forum user
Kate

The issue with a gas leak (if it is mains gas you are talking about) is not that it may make people ill, but the risk of fire and explosion.  I'm not sure why you are focusing on the pregnancy?

GazNicki2504  
#3 Posted : 30 March 2023 11:28:03(UTC)
Rank: Forum user
GazNicki2504

A slightly similar question was already raised on these forums in 2017. Please see here: RIDDOR Reportable? Gas pipe (iosh.co.uk)

As Kate has already stated, the risk with a Gas Leak is the risk of explosion. Your query revolves around the volume of gas being released, as mentioned in the link above.

peter gotch  
#4 Posted : 30 March 2023 12:11:34(UTC)
Rank: Super forum user
peter gotch

Hi Andrew

RIDDOR includes the following as "dangerous occurrences":

Release of flammable liquids and gases 26.The sudden, unintentional and uncontrolled release— (a) inside a building— (i) of 100 kilograms or more of a flammable liquid; (ii) of 10 kilograms or more of a flammable liquid at a temperature above its normalboiling point; (iii) of 10 kilograms or more of a flammable gas; or (b) in the open air, of 500 kilograms or more of a flammable liquid or gas.

Hazardous escapes of substances 27.The unintentional release or escape of any substance which could cause personal injury to any person other than through the combustion of flammable liquids or gases.

So, usually the issue is going to be that of an explosion risk, but you might have a risk of ill health that I think would fall under the scope of the words "personal injury".

There is no Workplace Exposure Limit set for natural gas (mostly methane) in contrast to LPG. However, in each case, the risk is more likely to be of asphyxiation resulting from a build up of gas reducing oxygen levels.

However, to be honest, if you have vented the room, I doubt that anyone is going to be in a position to demonstrate that the conditions were such as to make the scenario a RIDDOR reportable dangerous occurrence on the basis of either of the definitions above.

....and whilst I have always been in the camp of saying "If in doubt, report", if you report is so full of IFs and BUTs, HSE won't thank you for trying to add to the statistics.

I would recommend to ANY of those around at the time to talk to their GP if they continue to feel unwell, not least since a "leak" might be a build up of flue gases resulting from incomplete combustion which means potential Carbon Monoxide poisoning.

John Elder  
#5 Posted : 30 March 2023 12:51:46(UTC)
Rank: Forum user
John Elder

Hi Andrew

I would agree with Peter regarding the RIDDOR. 

It is understandable that you would be concerned about the pregnant person as you have a higher duty of care owed to them.

This is because some substances can be dangerous to the unborn child and not to the person themselves

Also as the event has now passed and been rectified, as opposed to its being live and ongoing, the explosion risk is currently no longer relevant and your actions to close out the documentation and procedures are relevant.

With natural gas there is both an exposure risk and explosion risk to be considered.

The TWA for Natural gas is 1000ppm or 0.1% whereas the lower explosion limit is 2% therefore it is possible to have a gas leak present throughout the course of the day which will never reach its lower explosion limit due to the leak rate and available ventilation but could still take a person being exposed to the gas over the TWA for exposure making them ill.

In most instances the exposure limits for flammable and combustible substances are far below the lower explosive limit of that substance. But bear in mind that both asphyxiation or an explosion usually have the same end result.

A Kurdziel  
#6 Posted : 30 March 2023 14:29:13(UTC)
Rank: Super forum user
A Kurdziel

We are assuming that the gas in question is natural gas. The real danger of a natural gas leak is the explosion risk not any effects the gas might have. Remember natural gas has an odorizer added to it which means people will notice a gas leak as opposed to carbon monoxide or another non-smelly but harmful/toxic gas.

The issue of pregnancy  is a bit of a red herring since in an office you would expect there to be no harmful  gases present at all. 

Kate  
#7 Posted : 30 March 2023 16:58:38(UTC)
Rank: Super forum user
Kate

Well, I don't find methane mentioned in EH40 so I conclude it hasn't got an exposure limit.

Here is the Public Health England (may it rest in peace) information sheet: https://www.gov.uk/government/publications/methane-properties-uses-and-incident-management

It suggests that any health effects are due to displacement of oxygen in the air rather than a toxic effect.  Hopefully no one was breathing enough methane for the amount of oxygen to be reduced to a dangerously low level!

peter gotch  
#8 Posted : 30 March 2023 17:51:13(UTC)
Rank: Super forum user
peter gotch

Kate and John

I think you are both correct to a point.

I couldn't find methane or natural gas in EH40 which is the relevant guidance for the UK.

However the US ACGIH has proposed a Threshold Limit Value of 1000 ppm for methane as an 8 hour Time Weighted Average.

In ye olden days when EH40 was very thin, the first point of reference was usually to look at what has happenening on the other side of the Pond.

Roundtuit  
#9 Posted : 30 March 2023 20:26:30(UTC)
Rank: Super forum user
Roundtuit

Finland & Romania have actual values for Methane accordimg to GESTIS https://limitvalue.ifa.dguv.de/

Roundtuit  
#10 Posted : 30 March 2023 20:26:30(UTC)
Rank: Super forum user
Roundtuit

Finland & Romania have actual values for Methane accordimg to GESTIS https://limitvalue.ifa.dguv.de/

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