Institute for Interlaboratory Studies

The independent institute organizes global interlaboratory studies on fuels, petroleum products, petrochemicals and consumer products. Studies are usually performed on commercially relevant products and involve testing on complete specifications. Any laboratory may participate using its own routine analytical methods.

Discover our annual program

Petroleum products

  • CHEMICALS
  • FUELS
  • GASES
  • LUBRICANTS and OILS
  • PETROLEUM PRODUCTS and OTHERS

Consumer products

  • COSMETICS AND PERSONAL CARE
  • LEATHER/FOOTWEAR
  • POLYMERS
  • TEXTILES
  • FOOD AND SKIN CONTACT MATERIAL, TOYS, DRIED PAINT
How it works

The process

Register your account

You are required to have authorisation from iis before you proceed with ordering products.

Order your products

Participation in some PTs may be limited due to limited stock of products. We therefore highly recommend to apply your registration as soon as possible.

Product dispatch

Once your participation is confirmed, we will ship the products to the address of your choice.

Confirm product receipt

You can confirm product receipt via your client account or the reporting portal.

Report your test results

You can submit your test results via the reporting portal.

Reports & Certificates

You will receive your Proficiency Test Report and you can download your certificates in your account. We use our protocol to run a Proficiency Test.

About us

Who we are

iis is an independent organization that provides various types of interlaboratory studies (proficiency tests, round robins, cross checks, collaborative trials) for analytical laboratories. The Institute is located in Spijkenisse - The Netherlands. Its clients - participating laboratories in interlaboratory studies - are found all over the world, in more than 100 countries.

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most recent iis Topics

Important: Reporting and scope of this weeks proficiency tests

Important: Reporting and scope of this weeks proficiency tests

Only for PTs with sample dispatch date on 18th June 2025 reporting of results should still be done on the previous data entry portal: SGS-iis: Oil, Gas & Chemicals or...

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New client portal

New client portal

  From June 3rd 2025 new iis client website! We are proud to inform you that this year, the Institute for Interlaboratory Studies is an accredited proficiency test provider for...

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