USDA NEWS, Fumigation and Packaging

USDA has been experiencing some problems with fumigation lately and has asked that we inform our Importers of these problems.  If you are currently importing any herb, fruit or vegetable shipments this very important information should be reviewed.
The following is a letter from USDA outlining these challenges.

From: USDA August 5, 2010

The past several months there have been many herb, fruit, and vegetable shipments requiring fumigation as a condition of entry or the Department of Homeland Security, Customs Border Protection has intercepted plant pests requiring treatment, however, the bagging or wrappings do not meet PPQ’s requirement for proper holes. For PPQ to have an efficacious treatment it is imperative that we have a way to get the fumigant into the packaging and the bagging to the commodities surfaces where the plant pest is. We cannot achieve the goal of killing the plant pests that do not occur in the United States without compliance. Also we do not want to trap the fumigant inside of these products for several reasons. The longer the fumigant stays inside the plastic bags or wrappings there is a possibly that fumigant could damage the commodity, may reduce shelf stability, and most importantly trap the fumigant inside of the bagging. Thus the fumigant could be released during the unpacking of the commodity at stores where these commodities are sold or in a warehouse where these products are held before being sent out to retailers.

Please check this website for more information, Treatment Manual, page 2-3-6.

*(We have provided a copy of the page from the manual below.)*

Chemical Treatments Fumigants • Methyl Bromide

Leak Detection and Gas Analysis

2-3-6 Treatment Manual 05/2010-45


To show that the fumigation using the “Q” label was monitored by a regulatory agent, the fumigator should record the name, title, telephone number and mailing address of the monitoring regulatory agent(s) on the restricted use pesticide application records, even if the same information is recorded on other documents (e.g., phytosanitary certificate).

Leak Detection and Gas Analysis

Use an APHIS-approved gas detection device to measure gas concentration levels in tarpaulins and chambers. Use an APHIS-approved leak detection device primarily to check for leaks around tarpaulins, chambers, application equipment, and as a safety device around the fumigation site. For a partial list of manufacturers of detection devices, refer to Reference Guide to Commercial Suppliers of Treatment and Related Safety Equipment. Colorimetric tubes, which are supplied by the fumigator, are used to measure gas concentration levels during aeration.

Effects of Temperature and Humidity

MB is effective at the same temperatures plants are generally handled (usually40 °F and above). In general, increases in temperature give a corresponding increase in the effectiveness of MB. All treatment schedule temperatures are listed with the corresponding dosage rate. Follow the dosage rates listed. A Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Section 3 registration (the labeled rate of MB provided), or a Section 18 Exemption must be in effect at the time of treatment. For live plant material which is actively growing or with leaves, maintain a high percentage of humidity (above 75 percent) in the chamber by placing wet sphagnum or excelsior in the chamber or by wetting the chamber walls and floor. Protect actively growing or delicate plants from the direct air flow of fans. Do not add any moisture to the chamber when fumigating seeds. Too much moisture on the material to be fumigated may prevent the fumigant from reaching some of the pests.

Penetration and Aeration of Boxes and Packages

Plastic Wrappings and Impermeable Papers

Plastic wrappings such as cellophane, films, and shrink wrap, and papers that are waxed, laminated, or waterproofed are not readily permeable and must be perforated, removed, or opened before fumigation .If wrappings are perforated to facilitate fumigation, holes should be at least 3/16-inch in diameter every 3 square inches or 1/4-inch in diameter every 4 square inches over the entire surface of the wrapping. Also acceptable are plastic wraps containing numerous pinholes (at least 49 per square inch). These holes enhance permeability through the plastic fruit trays, which are frequently used for transport of fruit.


Inform prospective importers that the wrappings on their shipments may have to be perforated to PPQ specifications, removed, or opened if PPQ requires fumigation. If wrappings on shipments are designed to satisfy PPQ requirements for fumigation readily, importers could save time and money. Shippers should send a complete bag/wrap sample to CPHST for inspection and approval.

If there are questions, individuals should contact CPHST for inspection and approval of bag/wrap. Samples should be sent to:

Treatment Quality Assurance Unit
1730 Varsity Drive, Suite 400
Raleigh, NC 27606
Attention Dean Komm


The bags must have the following:

·         Even spaced holes over surface of bag

·         1/4 inch diameter hole every 4 sq inches

·         3/16 inch diameter hole every 3 sq inches

·         49 pinholes per square inch

Other diameter holes may be used if they are evenly spaced and have at least a 0.93% open area of the bag surface.

Effective on Monday, August 23, 2010, PPQ will be refusing all commodities for fumigation if the bagging or wrappings do not meet these requirements. Please remember bagging or wrappings requirements apply to ALL counties. If you have any questions you may call USDA supervisor Randolph Cadet at 908-862-2012.

Thank you for your help in protecting the United States from foreign pests.