I'm working my way through the FDA's report on its inspections of the PCA facility. The agency made 10 observations, this post deals with #7.
The FDA has posted the report on its inspections of the PCA facility on the FDA website, here. As PCA has noted on its website, the FDA's findings are not final, and PCA will have the opportunity to respond.
Observation #7 notes that the building does not have positive air pressure in the production area. The idea here is that if the production area has postive air pressure, then when a door is opened to a warehouse, raw material storage, the outside, etc., air will flow out. If air flows in, there is the risk the air flow will carry in something nasty.
For a typical high volume peanut roasting operation, this is a problem, because the large roasters consume large volumes of air -- they have huge exhaust fans on them to take away smoke and cool the peanuts. To create positive air pressure in a roasting area would require a huge air make up unit to replace the air the roaster was exhausting out. The make up unit would use outside air, which, it seems to me, carries the potential for nasties as well. Unless this must be filtered in some way. This is not a simple fix.
PCA's problem, however, appears to have been more fundamental -- their production area was not behind a wall at all. Perhaps is this allowed by the Georgia Dep't of Ag. -- in Michigan, it is absolutely forbidden. All receiving and warehouse areas must be physically separated from production areas.