These are testing times for green foams
Published: 01 June, 2007
The purpose of the trip, explained ABC MacIntosh’s Gary McDowall was to demonstrate how environmental foams could be beneficial to the emergency services, and that going down the environmental route would not necessarily cost more.
The timing for the trip was considered to be quite appropriate. Only a few weeks earlier, DuPont had announced that is was phasing out the use of PFOA completely by 2015, in line with Environment Protection Agency’s voluntary program (announced last year) to eliminate PFOA in products by 2015.
Readers will know that PFOA by-product is found in aqueous film forming foam (AFFF), a component of fire-fighting foams.
While solid proof that PFOA is harmful to humans is yet to be conclusively documented, it is nevertheless highly controversial both as regards its potential toxicity, and its potential capacity to infiltrate the environment on a global, long-term basis.
DuPont has used PFOA for over 50 years at its Belpre plant in Ohio, and in 2001 was sued by residents who claimed PFOA contaminated the water. A settlement includes the testing of 60,000 residents to determine health effects. DuPont has also been investigated by the Environment Protection Agency for allegedly covering up knowledge of possible health effects of PFOA (2004) in a study of pregnant employees. In a separate incident in 2005, DuPont settled with the EPA (without any admission of liability) for failure to report violations under the Toxic Substances Control Act and the Resource Conservation and Recovery Act, to the tune of $10.25 million in fines, with an additional $6.25 million for two supplemental environmental projects. There are other similar incidents on record.
A remote 40,000 m2 testing facility surrounded by woods, river and numerous trees seemed an appropriate backdrop to consider the question of ecofoams.
The foams
Bio For N is a biodegradable solution for fighting class A fires in urban and industrial environments. A wetting and foaming additive, Bio For N can be used to extinguish car/house/waste tip fires, as well as rubber/plastic/wood/food and agricultural product fires. It can be used to generate low, medium and high expansion foams. As well as being non-toxic, and fully biodegradable, Bio For N contains no fluorine derivatives.
Ecopol is a fluorocompound-free, synthetic foam made from copra fatty acids, and can be used on class B, hydrocarbon and chemical fires. Ecopol is flexible enough to be used at low, medium and high expansion and at concentrations of 3-6 per cent on hydrocarbon fuels and on polar solvents. Manufacturer Bio-Ex describes Ecopol as the ultimate eco-friendly answer to traditional foams, being readily biodegradable and non-toxic to aquatic life.
Six tests were conducted using Bio For N and Ecopol. These two foams, incidentally, have been used in mainland Europe for a number of years, but in the UK they have so far only been taken up by one fire service, Mid and West Wales. Other brigades are currently considering it.
Test 1: refinery fire on a surface area 111m2 containing 2,000 litres of gasoil and petrol mix. Ecopol used at 3% at low expansion.
Test 2: alcohol fire on a surface area of 27.5m2 containing 500 litres of acetone. A fluoroprotein is used at 3% and 200 litres per minute at medium expansion.
Test 3: small tank fire on a surface of 28m2 with a 500 litre mix of gasoil and petrol. Bio For N used at 1% and 200 litres per minute, low expansion.
Test 4: twin tank fire on surface of 55m2 and 1,000 litres of gasoil and petrol. Bio For N at 1%, at 400 litres per minute at medium expansion.
Test 5: alcohol fire on surface of 27.5m2 and 500 litres of acetone. Ecopol used at 3% and at 200 litres per minute, medium expansion.
Test 6: RTA leaking tanker of heptane with surface area of 75m2. Ecopol used at low expansion and 400 litres per minute.
So what did the firefighters who witnessed the tests think about what they saw? Not surprisingly, there were many tongue-in-cheek comments surrounding the operational methods used both by the training centre’s firefighters and Gary MacDowall (‘they are standing too close to the flames!’). And putting aside the smiles of glee at the huge size of the fires and the resulting columns of smoke, the tests seemed to impress.
Some issues were raised, however.
The refinery fire test made one divisional head think about his current AFFF foam. “When you apply AFFF with a foam cannon it immediately wants to spread out and create a film on top. Ecopol does not form a film in the same way, so we would like to see a demonstration from a distance. In a large industrial fire you would not be able to get so close as to see where the foam is going, and with AFFF you can be far away and you know it will spread anyway.”
Test 3 provided some food for thought because it involved a class B fire (gasoil and petrol) being put out with a class A foam, as Gary Mcdowall explained, “This is a class B risk but we’re going to use class A. Technically it should not be able to put the fire out, but it will.” Yes, interestingly enough Bio For did put the fire out, but murmurings were heard to the effect of what type of firefighting idiot would use a class A foam on a class B risk.
Test 5 involving 500 litres of acetone and Ecopol foam also raised some eyebrows. “The firefighter is using medium expansion which means he’s having to get very close, which in a fuel fire you don’t want to do as it is very aggressive,” said one firefighter. “To my thinking, this may be due to the fact that this foam doesn’t form a film, so he has to ‘volume’ it - depend on the volume of the foam.”
Another concern was raised on the RTA leaking tanker scenario, “What would happen if the tanker was full of vapour? That’s when you get the explosion, and the firefighters are very close.”
Dr Thierry Bluteau from Bio-Ex was on hand to answer queries regarding the active ingredient in Ecopol that prevented the water being drawn out of the foam. “It is a combination of a special gum and a special surfactant, which glues the bubbles together so each bubble is coated in surfactant.
Mid and West Wales
Paul Bates, senior divisional officer at Mid and West Wales Fire & Rescue (MAWW), conducted a presentation outlining his experiences with environmental foams over the last five years.
MAWW currently uses Ecopol in six of its newer appliances, and Bio For N on all appliances with an integrated foam system (as class A capability) - 35 in total. “All our appliances have a round the pump proportioner to induce FP70 as our class B capability - we have stayed with this due to our large refinery risks.”
Paul outlined what prompted MAWW to look at the environmental impact of foam. Firstly, he said, was the Ground Water Regulations Act 1998 which prohibited the discharge of List 1 materials into the environment - including fluorosurfactant foams. A Fire and Rescue Circular (40/2006) also stated that with various fluorosurfactant-free foams being developed, services “should consider these where they can satisfy themselves that the fire performance meets local needs.”
There was another issue, explained Paul, that concerned MAWW, and that was low mains water pressure in its most rural areas. “Special surfactants in Bio For N allows water to penetrate solids thus multiplying it’s extinguishing power and prevents early restart. The use of Bio For N as a wetting agent improved water efficiency by as much as five times.”
MAWW is satisfied with its foams and no drawbacks in comparison with AFFF have been noted. “A benefit is that there are little restrictions to its use, both in terms of cost and environmental impact.” Indeed, when the foams’ data sheets were sent to the UK’s Environment Agency, said Paul, they came back with the following comments: “The foam is very good. It has low toxicity and is non toxic to aquatic life at 240 ppm”, and, “The product degrades quickly and will cause no long term damage.”
Adapting the appliances to the foam has not been a headache either. “All new appliances come with the designated Robwen system. With the older appliances we have just changed the foam as the system was compatible for Bio For N. The only alterations we have made is to change the inducing nozzles from 3% to 1%. The system worked just as well except that it used more foam than was required.”
The big question - disposal of old stocks
For most firefighters in Vigo the main issue was what to do with old, non-environmentally friendly stocks. As Borough Commander at Greater Manchester Fire & Rescue, Kevan Whitehead, put it, “I think the signs are extremely promising as regards eco-foams and doing nothing is no longer an option. Personally speaking, I might be a dinosaur but water for me is still good for putting fires out so I would consider Ecopol before Bio For N.
“Even if all the issues with ecofoams can be cleared up as regards performance, there is still another problem. All brigades have the ‘bad stuff’, and in Manchester we have 40,000 litres of it. Even if you love the concept, what do you do with old stocks? I think these suppliers should consider a package where the old foam can be traded in for new eco foams. Using the old foam for training purposes is not an option, and neither is selling it to the developing world, on moral grounds. I think if brigades were provided with this package then they would be more likely to take it up.” Next issue of IFJ ABC MacIntosh answers the firefighters’ queries on Ecopol and Bio For N, as well as operational techniques used at Cegalia training centre during the tests. We also find out more about Cegalia Mandford training centre.
