We've prepared this page to help address common questions regarding the ISTA Certificates.


General Information

Why is an ISTA certificate necessary?

Many seed-importing countries require an international seed test certificate issued by a laboratory that is accredited by the International Seed Testing Association (ISTA). Some countries, such as Australia, have strict requirements. An ISTA certificate from the originating country makes it possible to classify contaminants and to verify acceptability by the importer before the seed is shipped and may speed the process through customs and quarantine.

An international test certificate (orange or blue) by an accredited laboratory, in origin and prior to shipping, is invaluable in preventing potential delays and economic problems for the shipper and/or the importer.

What is an Orange International Certificate (OIC)?

Orange International Seed Lot Certificate represents the seed lot as a whole, therefore, seed lot preparation, lot size, lot identification and seed sampling must follow strict guidelines. The lab is responsible for both sampling and testing. Please see the Orange Certificates page for more detailed information.

What is a Blue International Certificate (BIC)?

The Blue International Seed Sample Certificate (BIC) represents only the seed sample that was tested. The sample is provided by the customer and the certificate does not officially represent the entire seed lot as does the OIC. As with the OIC, only ISTA accredited labs can issue the BIC, ensuring that the test results themselves are dependable. Because there is no sampling restriction, we can accept and test samples from customers located anywhere. Please see the Blue Certificates page for more detailed information.

How do I know if I need an Orange or Blue Certificate?

It depends on what is required by the importing country and/or importer. Because this is very often part of the seed contract, the seed lab can't determine what you need, but your importer should know. The testing rules are identical for both types of certificates.

If my seed is already certified, can the importer still require an ISTA certificate?

The importing customer may or may not require an ISTA certificate on certified seed lots. The exporter needs to check with the importer.

Does ISTA have seed quality standards like seed certification programs? 

No. Programs like Seed Certification have seed quality standards. In contrast, ISTA does not have seed quality standards as to minimum purity or germination requirements. What purity or germination levels are needed depends on your customers' needs. What ISTA does is make sure the test report is reliable and performed by a laboratory that has proven to be competent and authorized to perform such services.


Sampling and Samples

When should I order sampling for the OIC?

The OIC represents the lot of seed as it will be shipped, so sampling should be ordered only when the seed is ready to be shipped, after any treatment or rebagging. This restriction does not apply to seed certification or other sampling and testing activities. Setting the lot down: in the Willamette Valley, samplers can be expected to arrive within a day, so the lot needs to be set down at the time the request is submitted to the lab. It is the customer's responsibility to notify the warehouse to set the lot down.

What are the ISTA lot size requirements for OIC?

The ISTA Rules specify a maximum lot size for each species. A basic rule of thumb is that agricultural and vegetable seeds smaller than wheat, including most grass species, have a maximum lot size of 10,000 kilos. Larger seeds have larger maximum lot sizes, typically from 20,000 – 30,000 kilos. Lot sizes for other types of crops such as trees and flowers vary widely.  Maximum lot sizes can be found in Chapter 2 of the ISTA Rules, which is availble on their website (click on Free Rules Chapters).

Can I treat my seed after it is tested?

No. Certificates are valid only for the seed as it was tested, so treating it will invalidate the certificate since it will no longer accurately represent the seed. 

Can I rebag my seed after it has been sampled and tested for an Orange Certificate?

Rebagging is allowed provided that the identity of the seed in the initial lot is preserved, the lot number does not change, there is no processing of the seed, and an ISTA sampler is present during the entire process.

Can a BIC be issued on regular OSU samples?

The majority of samples received at the lab are samples submitted by the Oregon Seed Certification Service and commercial samples submitted by seed companies. These samples are acceptable for Blue International Certificates (BIC), as long as the necessary information to issue the certificate is provided, and a request is sent via Online Services.

If OSU already has test results based on AOSA Rules, can the results be converted for BIC?

It depends. The AOSA and ISTA Rules differ in sample size, testing procedures, and evaluation criteria for some species. If this is the case, a new test must be conducted for BIC. In most cases, we should be able to use the file sample at the lab to supply seed for the new tests.



What species is the OSU Seed Lab accredited for?

The Lab is accredited for all species listed in the ISTA Rules. Some species like Meadowfoam (Limnanthes alba), Seashore paspalum (Paspalum vaginatum), Chia (Salvia hispanica), and many native species are not in this list yet. Certificates cannot be issued for mixtures.  Please see Chapter 2 of the ISTA Rules to verify if the species can be tested for an ISTA Certificate, which is available on ISTA's website.

What tests is the OSU Seed Lab accredited for?

The lab is accredited for: purity (P), other seed determination (OSD), germination (G), tetrazolium (TZ), moisture (M), 1000 seed weight determination (1000wt), and endophyte (Festuca spp. and Lolium spp.). The lab is also accredited to test coated seed (except TZ). Our formal scope of accreditation may be viewed on the ISTA website.

What if my customer/country requires additional tests such as ploidy, grow-out, etc. that are not in the ISTA Rules?

If a customer requires grow-out, ploidy, or other tests not in the ISTA Rules, the lab will be able to provide these additional test results on an ISTA certificate as long as at least one ISTA test (e.g. purity, OSD, germ, etc.) also appears on the certificate. The additional test results are included under Other Determinations.

What is the Other Seed Determination (OSD) Test?

This test determines the presence of seeds other than the crop seed in a subsample of approx. 25,000 seeds. This is similar to the crop and weed exam in the AOSA system. All seeds found are listed by number in alphabetical order. Also known as an "Other Seeds by Number" test.

What is the scope of Other Seed Determination (OSD)?

This describes the quantity and species search parameters for the OSD.

OSD SCOPE Full Sample Smaller Sample
  • Complete: searches an entire large sub-sample (i.e. 25,000 seeds) for all species.
  • Limited: searches entire large sub-sample for specific species.
  • Reduced: searches a smaller sub-sample (i.e. more than 2500 but less than 25,000 seeds) for all species.
  • Reduced-Limited: searches a smaller sub-sample for specific species. The ISTA certificate will report the grams searched and the species found within the scope of search.



Will I see names of crops and weeds listed separately on my ISTA certificate?

Only if you request it. ISTA does not make this distinction – it is up to the customer and receiving country to determine if a species is a crop or weed. Likewise, common names vary widely around the world. If you want the species listed according to a specific scheme such as Australia, or New Zealand, you need to request this when you fill out the request. 

Who is listed as a client seed company on the ISTA certificate?

Whoever requests the ISTA certificate will be billed, however, the "Applicant" listed on the certificate will be typed exactly as requested. There is also the option to list a different applicant name than the bill-to customer. Please determine how this will best meet your needs, and enter this clearly on the Online Services request form. The applicant name is required for a Blue certificate but may be left off the Orange. 

What are Provisional, Original, Duplicate certificates?

  • Provisional certificates are issued before the completion of all requested tests (e.g. a purity result before germination is complete).
  • Original certificates are issued upon the completion of all tests.
  • Duplicates are exact copies of the Original and are identical to the Original in every way except the serial number and date issued. One Original certificate will be supplied for each sample tested; you must request Provisional and Duplicate certificates. All certificates state their status.

What is the fee for this service at the OSU Seed Laboratory?

For practical purposes fees are similar to the fees available for AOSA tests. Variations can occur due to sample size requirement. Please see our price list.