Importation of geological soils, including raw clays, is controlled by the United States Department of Agriculture, and as such, subject to federal regulations.

The first step in submitting samples to the Archaeometry Laboratory for analysis is to contact us. Ideally, this should be done during the planning phase of your project. We may be able to offer suggestions regarding analytical method, number of samples, and type of samples required that will save you both time and money. By explaining your project goals, you will help us to better understand your project and to better serve your needs.

Be sure to inform us of your intent to submit any soil or clay samples along with your project. Submission of all foreign or domestic USDA-regulated soil and clay samples requires that one of two procedures be followed. All soils from locations outside the U.S.A. and from certain locations within the U.S.A. are subject to these guidelines. To determine if your domestic soil or clay samples are regulated by the USDA, refer to this map.

If possible, the samples must be fired or steam heated according to the USDA Animal and Plant Health Inspection Service (APHIS) and Plant Protection and Quarantine (PPQ) Compliance Agreement.

To dry heat samples, soils or clays must be kept at a constant temperature for a specified period of time (Table 1). Note that the exposure period begins only after the entire sample has reached the specified temperature. If you are unsure, increase the exposure time to ensure that the entire sample has been thoroughly heated.

Table 1. Dry heat temperatures required to satisfy USDA APHIS & PPQ compliance agreement.

°Centigrade	°Farenheit	Exposure Period
110-120.5	230-240	16 hours
121-154	250-309	2 hours
154.4-192.5	310-379	30 min
193-220	380-429	4 min
221-232	430-450	2 min

To steam treat samples (autoclave), soil or clay should be placed in a horizontal tray, keeping the overall depth below 2 inches. Samples should be exposed to 15 lbs. of pressure for at least 30 minutes.

If you are unable to either heat or steam samples, you are required to obtain a copy of our USDA soil permit to accompany your soil samples in transit. All soil or clay must be placed in sturdy leak-proof containers and clearly labeled "Contents: Soil Samples" along with MURR ANID.