Incident Report

Subject:                   Australia NSW Safety Alert - Switchloading when transferring flammable liquids

Date of Email report:   Sat 11/08/2012

Report Detail:

Switchloading is defined as `when a flammable or combustible liquid is to be filled into a vehicle tank compartment which had previously contained a liquid having a lower flash point’ (Australian Standard AS1940:2004 The storage and handling of flammable and combustible liquids). This situation is most likely to arise, but not limited to, when a combustible liquid such as diesel is pumped into a tank that has previously contained petrol. While the tank may have been emptied of its liquid contents, it is likely to still contain flammable vapours that could ignite.

Risk controls

The controls identified in this safety alert are not exhaustive and a number of measures could be integrated into a system of work to ensure risks associated with the transfer of dangerous goods are effectively controlled.  The following are some of the control measures that should be considered to reduce the risks from the discharge of static electricity:

• all tanks, pipework, transfer systems (including decanting) and process plant associated with dangerous goods should be electrically bonded to each other and earthed, or otherwise protected (see AS/NZS1020 and AS4979 for advice)
• completely drain previously loaded liquid with the lower flashpoint
• ‘gas free’ the compartment where appropriate
• reduce loading rates to less than one m/s until the fill pipe is submerged
• use anti-static additives in non-conductive liquids
• ensure that hose and hose assemblies are appropriate for use with petroleum products

Read the full report here: Switchloading when Transferring Flammable Liquids

Additional Documentation:

Many JOIFF members will remember the Glenpool event and particularly the issues of emergency response and failures in emergency planning

An 80,000-barrel storage tank at ConocoPhillips Company’s Glenpool South tank farm in Glenpool, Oklahoma, exploded and burned as it was being filled with diesel. Gasoline had been removed from the tank earlier in the day. The resulting fire burned for about 21 hours and damaged two other storage tanks in the area. The cost of the accident was $2,357,483. There were no injuries or fatalities. Nearby residents were evacuated, and schools were closed for 2 days. The safety issues identified in this accident are tank operations, including switch loading, at the ConocoPhillips Company tank farm; the adequacy ofemergency planning and emergency response by ConocoPhillips and American Electric Power; and the adequacy of Federal regulations and industry standards foremergency planning.

Read the full report here.