[EricH]

Rihan, could you somehow let us know what the regulation is, or link to a site we can find it at?

I looked in the Manual, Section 4, and found the following, which should be at least somewhat compliant with US guidelines:

4.6.3. International Teams - Crates Crossing US Borders
The above sections apply to all crates. Crates crossing a US border have additional limits. Federal Rules apply to the crating and the pallets you will use to ship crates across US Borders to FRC events.
The US Dept. of Agriculture has adopted international guidelines to decrease the potential for the introduction of certain plant pests that may accompany wood materials arriving from other countries. The crate construction and pallet guidelines stipulate that wood packing materials be either heat treated or fumigated with methyl bromide in accordance with applicable rules. These wood materials must have the approved international mark certifying treatment.
ALL IMPORTS (with certain exceptions) WILL BE DENIED ENTRY IF THEIR WOOD PACKING MATERIAL DOES NOT CONFORM TO THESE GUIDELINES AND MARKING REQUIREMENTS.
All international teams, or US teams shipping into and out of the US, must do the following to comply:
• Use only plywood or other exempted wood materials when constructing their shipping crates and robots;
• If using raw wood materials such as 4” x 4”, 2” x 4”s, 1” x boards, etc…, obtain the materials from a lumber dealer who sells compliant wood products;
• Be sure the wood is marked with the approved international mark;
• Make sure you use properly treated and labeled wood for the 4” x 4”s under your crate used for facilitating forklift use;
• If you must use a pallet to ship your crate, make sure it is either non-wood or a compliant wood pallet, available from commercial pallet distributors;
• Canadian teams should obtain an appropriate importer’s statement as indicated; and
• Contact your local FedEx office for additional information and assistance. You can also find information at: http://fedex.com/us/promo/woodpackaging.html

If you use plywood, you can build your own bumpers. Unless the USDA or whoever oversees wood imports has something that specifically states that no wood from Australia can come into the US, you can use treated wood.