almond pasteurization

from the Almond Board (responsible for promoting almonds):
What types of pasteurization technologies are available?
While the Action Plan standard for treated almonds is a minimum 4-log reduction, a number of technologies have already been identified which result in a 5-log reduction – these include fumigation with propylene oxide  (PPO), blanching and oil roasting.  To review the Standard Operating Procedures (SOP) for PPO, please  click here.
from Wikipedia, the free encyclopedia:
Propylene oxide is a highly toxic flammable chemical compound. It was once used as a racing fuel, but that usage is now prohibited under the US NHRA rules for safety reasons. It is also used in thermobaric weapons, and microbial fumigation. It is an epoxide.

from the Department of Health and Human Services:
We would not object to the use of the term "pasteurized" on the label of bulk almonds that have been treated with PPO.