Rabbi Gavriel Price, Rabbinic coordinator, OU Kashruth, has discussed several issues pertaining to kosher tank cleaning. This month he reminds tank cleaning facilities that "kosher" should not be written on a wash receipt if the tank wash is not certified by an agency to do so. Receiving companies should question a wash receipt that's simply marked "kosher" on an upgrade wash, if there's no third party to substantiate it. A truck wash facility that is certified by a bona fide kosher agency can append a certificate indicating that the wash has been an upgrade wash.
There are two kinds of washes. One is called a kosher maintenance wash, and refers to a wash facility that maintains the kosher status of a carrier. Maintenance washes are used by a trailer that is already certified and that intends to stay in kosher status (that's why it's called a maintenance wash). An upgrade wash is necessary for a trailer that has not been kosher certified and now, because it has been selected to carry a kosher commodity, needs to be upgraded to that status.
How does an upgrade wash work? First, the water used in the prerinse should not be water that was used in the postrinse of a previous wash. An upgrade wash needs to (a) do a detergent wash at temperatures of upwards of 200 degrees F for 15 minutes, and (b) do a hot-water wash for about the same time. It's critical that the water from the spray-head hit all the walls of the interior of the trailer.
If a trailer undergoes such a wash, it can be considered kosher (Kosher means that the trailer conforms to kosher law. As pointed out before, it does not mean that the trailer has been blessed).
OU plans to keep Bulk Transporter informed of various kosher certification issues involving tank truck cleaning facilities, including updates on standardization. More information can be found on the OU and OU Kosher Web sites.