# DOT 3A, DOT 3AA, DOT 3A480X, DOT 4AA480 — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested

For DOT 3A, DOT 3AA, DOT 3A480X, DOT 4AA480, test or inspection is External visual inspection; interval is at five-year intervals after the first inspection; condition or service qualifier is Anhydrous ammonia of at least 99.95% purity; regulation section is 49 CFR § 180.209, recorded from its source on 2026-08-06.

- **Container specification:** DOT 3A, DOT 3AA, DOT 3A480X, DOT 4AA480 _(verified: appears in the quote below)_
- **Test or inspection:** External visual inspection _(our reading, not quoted from the source)_
- **Interval:** at five-year intervals after the first inspection _(verified: appears in the quote below)_
- **Condition or service qualifier:** Anhydrous ammonia of at least 99.95% purity _(verified: appears in the quote below)_
- **Regulation section:** 49 CFR § 180.209 _(verified: appears in the quote below)_

## What the source says

> DOT 3A, DOT 3AA, DOT 3A480X, DOT 4AA480 | Anhydrous ammonia of at least 99.95% purity.

## Source

- https://www.law.cornell.edu/cfr/text/49/180.209

Last verified: 2026-08-06. Review by: 2027-08-06.
Part of [How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested](https://referencesource.org/hazmat-container-retest-intervals/).