# All unlined cargo tanks — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested

For All unlined cargo tanks, test or inspection is Thickness Test; interval is 2 years; condition or service qualifier is transporting material corrosive to the tank, except MC 338; regulation section is 49 CFR § 180.407, recorded from its source on 2026-08-10.

- **Container specification:** All unlined cargo tanks _(verified: appears in the quote below)_
- **Test or inspection:** Thickness Test _(our reading, not quoted from the source)_
- **Interval:** 2 years. _(verified: appears in the quote below)_
- **Condition or service qualifier:** transporting material corrosive to the tank, except MC 338 _(verified: appears in the quote below)_
- **Regulation section:** 49 CFR § 180.407 _(verified: appears in the quote below)_

## What the source says

> Thickness Test: | | | All unlined cargo tanks transporting material corrosive to the tank , except MC 338 | September 1, 1992 | 2 years.

## Source

- https://www.law.cornell.edu/cfr/text/49/180.407

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/).