Several emails have been circulated over the past few months pertaining to “geysering” of chainsaws and other fuel containers when the fill cap is removed under tank pressurization conditions.   These accidents are occurring all too often, especially when the situation is easily preventable if individuals follow a few simple steps (see below).

The causes of fuel “geysers” has been studied extensively over the past year by San Dimas Research and Technology center.  Below is important information from San Dimas.

  1. The sudden expulsion (geyser) of fuel is caused by the fuel tank/container pressurizing.
  2. The initial “fix” for Stihl quarter turn gas caps, involved new “O” rings. However; after going thru field trials, this fix is not working.
  3. The “geyser” event can happen on all later model (> 2010) saw brands, fuel cans and drip torches. This is due to EPA requirements for non-venting fuel containers/systems.
  4. The event can happen with all blends/octanes and fuel-oil mixtures.
  5. It does not appear this problem can be “engineered” away.
  6. ALL saws, dolmars, sigs and fuel containers should be considered “pressurized” and appropriate precautions should be taken.

At this time the recommended “fix” is for operators to let saws cool, to move a least 10 feet from any open flame and to cover the saw cap with a rag while slowly (to relieve pressure) opening the tank.  All dolmars, sigs and fuel containers (including drip torches) have to potential to pressurize, and should caps should be covered while opening.

The following links provide additional good information on this subject:

Fuel geyser events

WFSTAR chainsaw safety video

6 minutes for safety Fuel can safety

6 Minutes for Safety Fuel handling safety

This is important information which must be disseminated to field going employees to prevent future incidents. Please help this message get out.