Postal Requirements

Mailing Oil Samples

Yes. Oil is safe and legal to send if the flashpoint is above 200°F or 93°C (which your engine oil sample is).

This letter explains to the USPS that your sample, in our kit, meets all postal regulations.

  • Our free test kit contains all the packaging you need.
  • Take a picture of the tracking number so you can see when it gets here.
  • Not using our kit? The sample should be:
    • In a bottle with a secure, screw-on lid
    • In a ziplock/recloseable bag
    • Surrounded by absorbent material
    • Addressed to: 
      Blackstone Laboratories
      416 E Pettit Ave
      Fort Wayne, IN 46806

This is the label to use!

Example of First Class Return Service label

Don’t use the Merchandise Return labels. 

Example of old Merchandise Return label