Generation of Flammable Mists from High Flashpoint Fluids
"There is a pressing need for clear guidance on mist
hazards to allow operators to determine the extent of areas where
flammable mists may be present and to select appropriate equipment
for use in those areas".
It is well-known that mists of high-flashpoint fluids such as
hydraulic oils, 
lubricating oils, diesel and heavier
fuels can ignite a produce explosions at temperatures below their
flashpoints. A review in 2009 identified 37 historical ignition
incidents involving flammable mists, including 20 explosions of
which nine were collectively responsible for a total of 29
fatalities. Nevertheless, both fire and explosion cause dangers to
workers, and in many cases the precautions required to prevent an
ignition are the same.
At present, Hazardous Area Classification (HAC) for explosive
gas atmospheres is well established. However, although there is a
legal requirement to consider flammable mists, the current
guidance on mist hazards is limited, brief and largely
qualitative.
To address this issue,
a project on the formation and mitigation of flammable
mists was initiated by HSE in December 2011 and jointly
sponsored by 16 industry and regulatory partners. This project
represented a major step forward in the understanding of this
phenomenon, but our knowledge of flammable mists remains limited.
HSE has now agreed in principle to support a follow-on project
under its new Shared Research Programme. A scoping workshop with
key industry stakeholders was held on 24th March at HSE's
Laboratory, where the current knowledge gaps and remaining research
questions were identified.
As a result, an outline
proposal for a programme of joint research has now been
produced. This briefly describes each of the proposed work packages
and provides an estimate of the resource required to deliver the
programme. HSE will be supporting the project financially; we are
now seeking support from industrial sponsors.
The final programme and the levels of investment required from
each sponsor will depend on the strength of support for this work.
Please review the proposal and share your thoughts with us on
whether you and your organisation would be interested in
participating.
For more information, or to express your interest in
sponsoring the work,
please contact Dr Paul Grant on +44 (0)203 028 2142 or email paul.grant@hsl.gsi.gov.uk