Managing The Risks Of RG22 Foam
The danger of using resin generated (RG) foam to fill redundant tanks on forecourts lies mainly in the assumption that it is risk free.
Resin generated foam, in its many forms – RG22, RG8 and RG30 – is now widely used on fuel sites everywhere. RG30 is used to encase fuel tanks for extra safety and contamination protection. RG8 is used for filling de-gassed tanks on a very temporary basis, as it is claimed that it may be completely broken down with water. RG22 is the most prevalent, as it’s widely used for the ‘permanent’ filling of tanks.
RG22 was first developed at a time when the solid fill material of choice was a 20:1 sand/cement slurry. To fill every part of the tank successfully with this, contractors needed to open the highest of the tank, pour within the slurry and agitate it; otherwise it will settle as a cone with space all around. Sometimes a part of the forecourt needed to be dug up if the manhole was in the wrong position.
The benefits of RG22 were that it was claimed to be safe, environmentally friendly and may very well be pumped in through an exiting pipe or a flange on the manhole lid. This made it a giant favourite with petroleum officers and oil companies, some of which began to insist on its use.
It was also cheaper than slurry and much lighter, which meant that the eventual excavation of the tank was claimed to be easier and inexpensive.
The introduction of foamed concrete has eroded some of these advantages, because it is way oil refinery jobs in texas city tx 6500 lighter than its predecessor and has similar flowing properties. Because of this, for many fuel site uses, there is now a viable alternative to RG22 that meets the requirements of oil companies and petroleum officers.
The main reason that we want another to RG foam is that it contains formaldehyde – a probable human carcinogen. In 2002, formaldehyde was placed on the US Report on Carcinogens 11th edition, compiled by the US Department of Health and Human Services, Public Health Service and the National Toxicology Program; something that holds only moral power in the UK and EU.
In Canada Urea-formaldehyde foam, which also uses formaldehyde as a curing aid, was used to insulate homes, particularly timber framed houses, but this has now been banned by the Canadian government after occupants complained of runny noses and sore eyes.
Because formaldehyde is used as a curing agent, while R22 needs to be handled with care at all times, the best health risk doesn’t occur when the foam is pumped into tanks in its liquid state, but rather when the so called ‘permanently’ filled tanks need to be excavated and removed, to allow a site to be decommissioned and used for another purpose.
The concerns are two-fold: handling the foam itself and exposure to the formaldehyde gas that’s given off when the tanks are excavated and cut up for disposal.
Because of its alleged properties, we were as curious about using RG22 as anyone else when it first came out. Our doubts began once we started excavating tanks that had been crammed with the foam and discovered how difficult and expensive it was to dispose of.
We discovered that RG22 can shrink, letting air get back into the tank, which reduces the safety effects of RG22 and hurries up corrosion. We later also discovered that it gave formaldehyde gas a spot to collect.
We now have excavated tanks lower than three months after they’ve been full of RG22 and the foam had already shrunk considerably. Then again, we’ve excavated tanks that were filled with RG22 two years previously and located that a few of the foam was still in a liquid state.
When our people opened the tanks they found the fumes were often overpowering and anyone who was unfortunate enough to touch the stuff received an unpleasant and uncomfortable skin rash as a reward. All our people now use an all-over bodysuit and breathing apparatus when dealing with RG22.”
The lightness of the foam was speculated to make excavation easier, allowing the tank containing the foam to be lifted straight from the ground and onto the back of a lorry. Unfortunately we discovered that there are only one or two disposal sites that can accept tanks with RG22 still inside. Even then, they’ll only accept small tanks, and then only when they can be placed in a deep part of the landfill site.
We are going to only attempt the all-in-one approach when our client insists, as we prefer the more environmentally friendly approach of sending the metal of the tank for recycling. This implies that after it has been faraway from the ground, the excavated tank has to be cut away, with the metal taken to at least one site and the RG22 to a different – usually a hazardous waste site.
We’re not the one ones to have concerns, another company in our sector told us: “RG foam is ok if the tank was never going to be opened again; the issue is that, lately, eventually, many tanks will have to be removed, if the site is to be sold on for development.
“My concern is, when we cut the tanks open there is a very pungent smell of formaldehyde and often an irritated feeling within the throat and eyes.
“We now use a special technique where we try to make use of heavy machinery to open the tanks up, keeping personnel away from the excavation.
“It would appear that the issue lies in the truth that through the curing the foam emits a fair amount of formaldehyde gas, which is trapped in the tank, to be released only when it’s cut open.
“Our workforce also initially noticed some irritation through exposure to the foam and, indeed, the manufacturers’ data sheet says it’s a ‘light irritant’.”
This company believes the main problem is that, as well as being an irritant, the fabric is light and friable, so, if precautions usually are not taken, it may possibly get under clothing or even be breathed in.
“However,” says the corporate, “this a part of the problem can be dealt with if contractors are properly forewarned. Like some other risk, they can deal with it, in the event that they know exactly what they are facing, by elimination, in the first instance and, where not possible, control techniques reminiscent of wearing protective clothing, gloves masks, eye protection etc.
“An even bigger problem is that fuel sites undergoing decommissioning are normally bounded by roads and pavements, often in built up areas, so there’s a danger that the light friable foam can easily be blown off the site. Lately we do not remove these foams on a day when there may be any wind at all.
“However, as I said, the issues associated with the foam itself will be handled using some simple precautions, our real concern is the formaldehyde gas that is given off when the tanks are cut into, as they should be when a site is decommissioned.”
Experience has shown us that air pockets occur, where the gas tends to concentrate, leading to a burst of gas being released when these pockets are breached.
Proximity is the real problem. Once formaldehyde gas is vented to atmosphere it will disburse to a harmless level, but if you are near the tank when it is cut it is more worrying.
Environmental and private monitoring was carried out by a company in our sector, taking a look at the extent of concentration of formaldehyde gas on fuel sites being decommissioned when tanks are cut open.
In one of these tests, formaldehyde sensors were placed at four strategic points on the site. Three produced results of under the recommended level of two parts per million, but the closest sensor, located 3m from the tank, registered 2.07 parts per million, which exceeds the UK workplace exposure limits (WEL) of two.0 parts per million, currently listed in HSE publication EH40/2005 Workplace Exposure Limits.
This indicates that steps have to be taken to protect oil refinery jobs in texas city tx 6500 anyone going within that distance.
We also believe that the two parts per million limit itself needs examination, as there may be, in my opinion, no real evidence for this level, a technique or the other. Rather more research is required.
The message is to be aware of the risks and take the correct precautions.
The principle problem is the respiratory system and the eyes, so we use a helmet, with a visor and a power assisted respirator.
Their message to petroleum officers and oil companies is to not get seduced by the alleged advantages of RG foam, to look at where it is appropriate to make use of it.
RG foams have their place in the mix, they should not be seen as the primary resort.
It could also be slightly cheaper to make use of RG22 to fill the tanks in the first place, but any savings are outweighed by the extra disposal costs and precautions that should be put in place.
Hierarchy of dealing with hazards.
If the job is hazardous, does it actually need doing
If the job is basically necessary, then can the hazardous material be substituted with something more benign, reminiscent of slurry, foamed concrete or polyurethane, which is now being sold instead in the US, but not here yet.
3. Change working methods
Using more machinery to cut back direct contact. Paying more attention to the weather on excavation days.
Increased use of non-public protection equipment (PPE) and paying more attention to oil refinery jobs in texas city tx 6500 containment within the positioning.