THINK DETAILS FOR FLAMMABILITY

                         Is there time to respond?

Part of the response should be to remove all ignition sources such as naked flames, hot surfaces, sparks (refer to explosivity - Think Details  - Is there time to respond?).                

            Another method of combating a flammable pool of a floating liquid is to apply spray foam to form a foam blanket which can temporarily reduce the vapour concentration above the liquid pool surface, decrease the evaporation rate, provide a barrier to thermal or solar radiation and in some cases, inhibit ignition or flame propagation.  It helps to coral (boom) the floating liquid before applying the foam.

Diagram:  How a foam works

            There are various types of foams for mitigating vapour formation.  Low expansion foams mitigate a spill by forming a barrier to vaporization whilst high expansion foams engulf the vapours, thereby reducing the vapour concentration directly above the foam layer.

Foams and their effectiveness               Property             Protein       Fluoro    AFFF         FFFP      Universal     Hazmat

                                                                                                                protein

                                                                _____________________________________________________________

                                                                Cohesion          xxx               xxx               x            xx             xx                   xx

                                                                Vapour

                                                                suppression     xxx               xxx               xx           x              xxx                 xxx

                                                                Stability/

                                                                water ret.           xxx               xx                 x            x              xx                   xxx

                                                                Heat

                                                                resistance         xxx               xxx               xx           x              xxx                 x

                                                                Fuel

                                                                tolerance           0                  xxx               xxx         xxx           xxx                 N/A

                                                                Alcohol

                                                                tolerance           0                  0                  0            0              xxx                 0

                                                                Chemical

                                                                resistance         0                  0                  0            0              0                    xxx

                                                                _____________________________________________________________

                                                                AFFF   = Aqueous film forming foam

                                                                FFFP  = Film forming fluoro-proteins

                                                                xxx       = Excellent

                                                                xx         = good

                                                                x          = Poor

                                                                0          = Insufficient

                                                                N/A      = Not applicable (this foam is not used for fire-fighting)

                                                                Protein, Fluoroprotein, FFF and FFFP foams are for fire-fighting and vapour suppression of hydrocarbons.  Universal foam is for fire-fighting and vapour suppression of hydrocarbons and solvents, and Hazmat foam is for vapour suppression of toxic chemical spills.  It is important to consult the manufacturer’s literature for foam specifications pertinent to the product spilled.

            Controlled combustion is another response possibility if the substance is flammable.  Careful planning is required to ensure safety conditions as well as a thorough assessment of all risks involved, such as reaction by products.  Weather conditions should also be suitable.

                          THINK DETAILS FOR FLAMMABILITY

Diagram:  An incendiary device  with a delay primer is activated  by pulling out a firing clip.

It is then dropped from a helicopter or fixed-wing aircraft onto the flammable liquid slick.  The delay primer

ignites the incendiary material after the firing clip is removed to initiate self-sustained combustion

of the flammable liquid spilled