# Specification 51 portable tank — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested

For Specification 51 portable tank, test or inspection is periodic inspection and test; interval is at least once every five years; regulation section is 49 CFR § 180.605, recorded from its source on 2026-08-10.

- **Container specification:** Specification 51 portable tank _(verified: appears in the quote below)_
- **Test or inspection:** periodic inspection and test _(our reading, not quoted from the source)_
- **Interval:** at least once every five years _(verified: appears in the quote below)_
- **Regulation section:** 49 CFR § 180.605 _(verified: appears in the quote below)_

## What the source says

> (2) Each Specification 51 portable tank must be given a periodic inspection and test at least once every five years.

## Source

- https://www.law.cornell.edu/cfr/text/49/180.605

Last verified: 2026-08-10. Review by: 2027-08-10.
Part of [How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested](https://referencesource.org/hazmat-container-retest-intervals/).