Minnesota Department of Health Environmental Lab
Trip Blank Policy
What are trip blanks?
A trip blank consists of a sample container or set of containers filled at the laboratory with water
demonstrated to be target analyte free. The trip blank travels to the sampling site with the empty
sample containers and returns from the site with the full sample containers.
Why are trip blanks used?
By duplicating the handling, environment and storage that the sample containers undergo, trip blanks
are used to measure possible contamination of samples. Trip blanks are typically analyzed for volatile
organic compounds but may be used for other analyses such as PFCs.
How are trip blanks used?
Trip blanks should not be opened in the field. They must return to the laboratory with the set of
containers they accompanied into the field.
Trip blanks should be submitted to the laboratory in the same manner as routine samples. They are to
be listed on the same Laboratory Request Form as the samples they are associated with. All trip blank
containers should be uniquely identified. Uniquely identified trip blanks are samples that can only be
linked to a single sample point on a single Laboratory Request Form. Note: Collection date and time are
not unique identifiers per MDH Sample Acceptance Policy. The date and time for the trip blanks should
be filled in using the collection date and time of the first sample the trip blanks are associated with.
When do the trip blanks expire?
All trip blank containers should have an expiration date on the label provided by MDH. All associated
samples must be collected prior to the trip blank expiration date.
What are some examples of properly labeled trip blank containers?
ops022 Trip Blank Policy
rev. 0, Effective: May 14, 2014
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