Before beginning the barrel fumigation process, post warning signs at all en- trances to the area. Include on these signs the following statements in English and Spanish:
the signal word DANGER/PELIGRO in 2-inch letters
the skull and crossbones symbol
the statement: “Area Under Fumigation - DO NOT ENTER/NO ENTRE”
the date and time of fumigation
name of fumigant used: Sulfur Dioxide – SO2 Gas
name, address, and telephone number of the applicator
Keep warning signs posted until after the application is complete, which means after aeration and monitoring verifies that the ambient air concentration is below the safe and legal limit of 2.0 ppm SO2. Do not allow anyone into the area until testing confirms it is safe to enter.
Attach a barrel gassing unit with a pressure gauge to the SO2 cylinder (obtain this equipment from the sulfur dioxide cylinder supplier), and open the cylinder valve. Be sure that the pressure gauge stays within the range of about 18 to 45 psi throughout the fumigation process. Most users prefer 20 psi. When the pressure drops below this level, connect a new cyl- inder to the gassing unit.
Begin treatment by removing the bung from the cleaned barrel, insert the SO2 wand into the barrel, then open the wand valve for 2-3 seconds. Immediately close the wand valve, remove the SO2 probe, and seal the barrel opening. Repeat this process for each barrel you are fumigating.
During the fumigation process, regularly monitor the air in the work area to assure that the SO2 concentration does not exceed 2.0 ppm. If readings are above 2.0 ppm, you and all other workers must leave the area immediately or put on approved supplied air respirators until the SO2 level in the atmosphere drops to or below 2.0 ppm. You must determine the problem causing the unsafe concentration, and work cannot resume until the cause is corrected.
Store the sealed treated barrels for at least one and no more than 30 days before filling them with grape juice or wine. Any barrels stored for more than 30 days must be retreated before using them.
FUMIGATING WINE BOTTLE CORKS
Fumigating corks before bottling reduces the effects of non-public health fungal or bacterial growth prior to corking the bottles. This minimizes contamination of wine in the bottles. You use the same process for fumigating corks as for fumigating wine barrels. Use an SO2 cylinder that contains gas only, not a cylinder that contains liquid SO2. Be sure the cylinder provided by the supplier has a pressure gauge and that the pressure in the cylinder is in the range of about 20 psi. When the pressure drops below this level, use a fresh cylinder.
SANITIZING WOODEN WINE BARRELS AND WINE BOTTLE CORKS