Students to create flame retardant for polystyrene using bacteria

Leicester students are aiming to make polystyrene more fire resistant using genetically modified bacteria – creating a new, safer fire retardant.

University of Leicester undergraduates have formed a team to enter this year’s International Genetically Engineered Machine competition (iGEM), following on from last year’s successful entry.

The team hopes to make use of DNA’s recently discovered application as a flame retardant to make expanded polystyrene (EPS) less flammable.

In order to produce large amounts of DNA at low costs, the students hope to genetically engineer bacteria to produce much more DNA in their cells than usual.

The DNA-rich bacteria could then be added to the polystyrene to make it less susceptible to burning.

Expanded PolyStyrene (EPS) – which is frequently used for insulation in buildings - is highly flammable and Hexabromocyclododecane (HBCD) is often added as a flame retardant in construction applications.

However, the European Union organisation, REACH, has listed HBCD as a “persistent bio-cumulative toxin” meaning that it can accumulate in the environment and alter biological processes, such as hormone levels in fish.

REACH is phasing out HBCD by 2015, so the University says developing an alternative flame retardant would be very good for the environment and the EPS industry.

Team Instructor, Dr Richard Badge, a Lecturer in Bioinformatics in the University's Department of Genetics, said: “Polystyrene is very flammable, but one of its biggest uses is in insulating building. So, while expanded polystyrene is a fantastic insulator, it needs to be made less flammable.”

“HBCD is the main chemical that has been used to make polystyrene fire retardant, but the European organisation REACH is phasing it out, so industry is going to be really interested in developing new fire retardants.”

“Bacteria are not particularly DNA rich, so we want to engineer the bacteria to contain more DNA. To do this, we are going to use bacteriophages – a virus which infects and replicates inside bacteria. The idea is to engineer bacteria that will produce lots of DNA once we give them the right signal.”

“The iGEM competition is a great opportunity for students to take part in. The sky is the limit in terms of what you can do with the DNA parts – it really is just down to the student's imaginations.”

UK-based firm Jablite, who manufacture fire-retardant polystyrene for the construction industry, and sister company Styropack specialising in polystyrene packaging for food and medicine, are supporting the team's project with materials and invaluable technical expertise.