Mandatory requalification, retest and inspection intervals for pressure containers under 49 CFR Part 180, with the qualifier that decides which interval applies. Each record is one container specification under one test type, stating the interval in years and the condition attached to it. Covers cylinders (49 CFR 180.209), cargo tanks (180.407), intermediate bulk containers (180.352) and portable tanks (180.605). Answers 'how often does a scuba tank need hydro testing', 'DOT 3AL requalification 5 years or 12', 'IBC tote retest interval 2.5 years', 'MC-331 propane cargo tank internal visual inspection frequency', and 'when does a DOT 3AA cylinder qualify for the 10 year star'. The interval is a property of the specification, the service and the configuration together, not of the container alone, and the exceptions are where the answers go wrong: DOT 3AL is 5 or 12 years depending on service, and an MC-331 under 3,500 gallons in dedicated propane service built from non-quenched-and-tempered SA-612 gets 10 years where every other cargo tank gets 5. Past the due date the container may not be filled and offered for transportation.

Facts extracted from the US Code of Federal Regulations, a US government work not subject to copyright. Text is read via law.cornell.edu because eCFR blocks our fetcher; the fact is the regulation's, not Cornell's, and each record quotes a short verbatim span and links back to the section.

How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 4B, 4BA, 4B240ET or 4BW

**Test or inspection:** proof-pressure test

**Interval:** by the end of 12 years after the original test date and at seven (7) year intervals

**Condition or service qualifier:** a water capacity over 5.44 kg (12 pounds)

**Regulation section:** 49 CFR § 180.209

> For a cylinder having a water capacity over 5.44 kg (12 pounds), by the water-jacket, direct expansion or proof pressure test methods as prescribed in CGA C-1. For the water-jacket or direct expansion test, the requalification must be performed by the end of 12 years after the original test date and at 12-year intervals theafter. For the proof-pressure test, a requalification must be performed by the end of 12 years after the original test date and at seven (7) year intervals.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 4B, 4BA, 4B240ET or 4BW — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 4B, 4BA, 4B240ET or 4BW

**Test or inspection:** water-jacket or direct expansion test

**Interval:** by the end of 12 years after the original test date and at 12-year intervals theafter

**Condition or service qualifier:** a water capacity over 5.44 kg (12 pounds)

**Regulation section:** 49 CFR § 180.209

> For a cylinder having a water capacity over 5.44 kg (12 pounds), by the water-jacket, direct expansion or proof pressure test methods as prescribed in CGA C-1. For the water-jacket or direct expansion test, the requalification must be performed by the end of 12 years after the original test date and at 12-year intervals theafter. For the proof-pressure test, a requalification must be performed by the end of 12 years after the original test date and at seven (7) year intervals.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>


**Container specification:** DOT 4BW

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Alkali metal alloys, liquid, n.o.s., Alkali metal dispersions or Alkaline earth metal dispersions, Potassium, Potassium Sodium alloys and Sodium that are commercially free of corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 4BW | Alkali metal alloys, liquid , <https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=ce9675606a240905d07508526a234d2a&term_occur=999&term_src=Title:49:Subtitle:B:Chapter:I:Subchapter:C:Part:180:Subpart:C:180.209> n.o.s ., Alkali metal dispersions or Alkaline earth metal dispersions, Potassium , Potassium Sodium alloys and Sodium that are commercially free of corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 4BW — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A, DOT 3AA, DOT 3A480X, DOT 4AA480

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Anhydrous ammonia of at least 99.95% purity

**Regulation section:** 49 CFR § 180.209

> 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>

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


**Container specification:** DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Anhydrous mono, di, trimethylamines that are commercially free from corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW | Anhydrous mono, di, trimethylamines that are commercially free from corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Butadiene, inhibited, that is commercially free from corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW | Butadiene, inhibited, that is commercially free from corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

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


**Container specification:** DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Chlorinated hydrocarbons and mixtures thereof that are commercially free from corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E | Chlorinated hydrocarbons and mixtures thereof that are commercially free from corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B. DOT 4AA480, DOT 4B, DOT 4BA, DOT 4BW

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Cyclopropane that is commercially free from corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B. DOT 4AA480, DOT 4B, DOT 4BA, DOT 4BW | Cyclopropane that is commercially free from corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

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


**Container specification:** DOT-3AL Cylinders Made of Aluminum Alloy 6351-T6

**Test or inspection:** Eddy current examination combined with visual inspection

**Interval:** 5

**Regulation section:** 49 CFR § 180.209

> Table 4 to Paragraph (m)—Requalification and Inspection of DOT-3AL Cylinders Made of Aluminum Alloy 6351-T6 Requalification requirement | Examination procedure 1 | Sustained Load Cracking Condemnation Criteria 2 | Requalification period (years) | Eddy current examination combined with visual inspection | Eddy current—In accordance with Appendix C of this part Visual inspection—In accordance with CGA Pamphlet C-6.1 (IBR; see <https://www.law.cornell.edu/cfr/text/49/171.7> § 171.7 of this subchapter) | Any crack in the neck or shoulder of 2 thread lengths or more | 5

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT-3AL Cylinders Made of Aluminum Alloy 6351-T6 — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 4B240, DOT 4BW240

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Ethyleneimine, stabilized

**Regulation section:** 49 CFR § 180.209

> DOT 4B240, DOT 4BW240 | Ethyleneimine, stabilized .

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 4B240, DOT 4BW240 — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Fluorinated hydrocarbons and mixtures thereof that are commercially free from corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E | Fluorinated hydrocarbons and mixtures thereof that are commercially free from corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>


**Container specification:** DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Liquefied hydrocarbon gas that is commercially free of corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E | Liquefied hydrocarbon gas that is commercially free of corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Liquefied petroleum gas that meets the detail requirements limits in Table 1 of ASTM 1835, Standard Specification for Liquefied Petroleum (LP) Gases

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E | Liquefied petroleum gas that meets the detail requirements limits in Table 1 of ASTM 1835, Standard Specification for Liquefied Petroleum (LP) Gases

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>


**Container specification:** DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Methylacetylene-propadiene, stabilized, that is commercially free from corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E | Methylacetylene-propadiene, <https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=ded9d0badd8fb463b3ce91a8cc58619c&term_occur=999&term_src=Title:49:Subtitle:B:Chapter:I:Subchapter:C:Part:180:Subpart:C:180.209> stabilized , that is commercially free from corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT-8 series

**Test or inspection:** Porous filler requalification

**Interval:** 5 to 20 years

**Condition or service qualifier:** On or after January 1, 1991

**Regulation section:** 49 CFR § 180.209

> Each owner of a DOT-8 series cylinder used to transport acetylene must have the cylinder shell and the porous filler requalified in accordance with CGA Pamphlet C-13 (IBR, see <https://www.law.cornell.edu/cfr/text/49/171.7> § 171.7 of this subchapter). Requalification must be performed in accordance with the following schedule: Date of cylinder manufacture | Shell (visual inspection) requalification | Porous filler requalification | Initial | Subsequent | Intial | Subsequent | Before January 1, 1991 | Before January 1, 2001 | 10 years | Before January 1, 2011 | Not required. | On or after January 1, 1991 | 10 years 1 | 10 years | 5 to 20 years 2 | Not required.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT-8 series — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT-8 series

**Test or inspection:** Shell (visual inspection) requalification

**Interval:** 10 years

**Condition or service qualifier:** On or after January 1, 1991

**Regulation section:** 49 CFR § 180.209

> Each owner of a DOT-8 series cylinder used to transport acetylene must have the cylinder shell and the porous filler requalified in accordance with CGA Pamphlet C-13 (IBR, see <https://www.law.cornell.edu/cfr/text/49/171.7> § 171.7 of this subchapter). Requalification must be performed in accordance with the following schedule: Date of cylinder manufacture | Shell (visual inspection) requalification | Porous filler requalification | Initial | Subsequent | Intial | Subsequent | Before January 1, 1991 | Before January 1, 2001 | 10 years | Before January 1, 2011 | Not required. | On or after January 1, 1991 | 10 years 1 | 10 years | 5 to 20 years 2 | Not required.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>


**Container specification:** 3

**Test or inspection:** Periodic requalification

**Interval:** 5.

**Minimum test pressure:** 3000 psig

**Regulation section:** 49 CFR § 180.209

> 3 | 3000 psig | 5.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

3 — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 3A, 3AA

**Test or inspection:** Periodic requalification

**Interval:** 5, 10, or 12

**Minimum test pressure:** 5/3 times service pressure, except non-corrosive service

**Regulation section:** 49 CFR § 180.209

> 3A, 3AA | 5/3 times service pressure, except non-corrosive service ( see <https://www.law.cornell.edu/cfr/text/49/180.209#g> § 180.209(g) ) | 5, 10, or 12 ( see <https://www.law.cornell.edu/cfr/text/49/180.209#b> § 180.209(b) , (f), (h), and (j)).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

3A, 3AA — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 3AL

**Test or inspection:** Periodic requalification

**Interval:** 5 or 12

**Minimum test pressure:** 5/3 times service pressure

**Regulation section:** 49 CFR § 180.209

> 3AL | 5/3 times service pressure | 5 or 12 (see <https://www.law.cornell.edu/cfr/text/49/180.209#j> § 180.209(j) and (m) 4 ).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

3AL — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 3AX, 3AAX

**Test or inspection:** Periodic requalification

**Interval:** 5.

**Minimum test pressure:** 5/3 times service pressure

**Regulation section:** 49 CFR § 180.209

> 3AX, 3AAX | 5/3 times service pressure | 5.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

3AX, 3AAX — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 3B, 3BN

**Test or inspection:** Periodic requalification

**Interval:** 5 or 10

**Minimum test pressure:** 2 times service pressure

**Regulation section:** 49 CFR § 180.209

> 3B, 3BN | 2 times service pressure ( see <https://www.law.cornell.edu/cfr/text/49/180.209#g> § 180.209(g) ) | 5 or 10 ( see <https://www.law.cornell.edu/cfr/text/49/180.209#f> § 180.209(f) ).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

3B, 3BN — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 3E

**Test or inspection:** Periodic requalification

**Minimum test pressure:** Test not required

**Regulation section:** 49 CFR § 180.209

> 3E | Test not required

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

3E — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 3HT

**Test or inspection:** Periodic requalification

**Interval:** 3

**Minimum test pressure:** 5/3 times service pressure

**Regulation section:** 49 CFR § 180.209

> 3HT | 5/3 times service pressure | 3 ( see <https://www.law.cornell.edu/cfr/text/49/180.209#k> §§ 180.209(k) and 180.213(c)).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

3HT — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 3T

**Test or inspection:** Periodic requalification

**Interval:** 5.

**Minimum test pressure:** 5/3 times service pressure or UE

**Regulation section:** 49 CFR § 180.209

> 3T | 5/3 times service pressure or UE 3 | 5.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

3T — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 4AA480

**Test or inspection:** Periodic requalification

**Interval:** 5 or 10

**Minimum test pressure:** 2 times service pressure

**Regulation section:** 49 CFR § 180.209

> 4AA480 | 2 times service pressure ( see <https://www.law.cornell.edu/cfr/text/49/180.209#g> § 180.209(g) ) | 5 or 10 ( see <https://www.law.cornell.edu/cfr/text/49/180.209#h> § 180.209(h) ).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

4AA480 — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 4B, 4BA, 4BW, 4B-240ET

**Test or inspection:** Periodic requalification

**Interval:** 5, 7, 10, or 12

**Minimum test pressure:** 2 times service pressure, except non-corrosive service

**Regulation section:** 49 CFR § 180.209

> 4B, 4BA, 4BW, 4B-240ET | 2 times service pressure, except non-corrosive service ( see <https://www.law.cornell.edu/cfr/text/49/180.209#g> § 180.209(g) ) | 5, 7, 10, or 12 ( see <https://www.law.cornell.edu/cfr/text/49/180.209#e> § 180.209(e) , (f), and (j)).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

4B, 4BA, 4BW, 4B-240ET — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 4D, 4DA, 4DS

**Test or inspection:** Periodic requalification

**Interval:** 5.

**Minimum test pressure:** 2 times service pressure

**Regulation section:** 49 CFR § 180.209

> 4D, 4DA, 4DS | 2 times service pressure | 5.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

4D, 4DA, 4DS — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 4E

**Test or inspection:** Periodic requalification

**Interval:** 5, 10, or 12

**Minimum test pressure:** 2 times service pressure, except non-corrosive service

**Regulation section:** 49 CFR § 180.209

> 4E | 2 times service pressure, except non-corrosive service ( see <https://www.law.cornell.edu/cfr/text/49/180.209#g> § 180.209(g) ) | 5, 10, or 12 ( see <https://www.law.cornell.edu/cfr/text/49/180.209#e> § 180.209(e) ).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

4E — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 4L

**Test or inspection:** Periodic requalification

**Minimum test pressure:** Test not required

**Regulation section:** 49 CFR § 180.209

> 4L | Test not required

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

4L — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** 8, 8AL

**Test or inspection:** Periodic requalification

**Interval:** 10 or 20

**Regulation section:** 49 CFR § 180.209

> 8, 8AL | | 10 or 20 ( see <https://www.law.cornell.edu/cfr/text/49/180.209#i> § 180.209(i) ).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

8, 8AL — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** Exemption or special permit cylinder

**Test or inspection:** Periodic requalification

**Interval:** See current exemption or special permit

**Minimum test pressure:** See current exemption or special permit

**Regulation section:** 49 CFR § 180.209

> special permit cylinder | See current exemption or special permit , or UE 3 as allowed by CGA C-20 (2014) | See current exemption or special permit .

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

Exemption or special permit cylinder — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** Foreign cylinder

**Test or inspection:** Periodic requalification

**Interval:** 5

**Minimum test pressure:** As marked on cylinder, but not less than 5/3 of any service or working pressure marking

**Regulation section:** 49 CFR § 180.209

> Foreign cylinder ( see <https://www.law.cornell.edu/cfr/text/49/173.301#j> § 173.301(j) of this subchapter for restrictions on use) | As marked on cylinder , but not less than 5/3 of any service or <https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=9cea27360a19f92652d9719fb84b14e4&term_occur=999&term_src=Title:49:Subtitle:B:Chapter:I:Subchapter:C:Part:180:Subpart:C:180.209> working pressure <https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=eb918f673baa7b9803c95ffddc5d1ef5&term_occur=999&term_src=Title:49:Subtitle:B:Chapter:I:Subchapter:C:Part:180:Subpart:C:180.209> marking | 5 ( see <https://www.law.cornell.edu/cfr/text/49/180.209#l> §§ 180.209(l) and 180.213(d)(2)).

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

Foreign cylinder — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E

**Test or inspection:** External visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** Propylene that is commercially free from corroding components

**Regulation section:** 49 CFR § 180.209

> DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E | Propylene that is commercially free from corroding components.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT 4E — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT Specifications 4B, 4BA, 4BW, or 4E

**Test or inspection:** volumetric expansion testing

**Interval:** every 12 years instead of every 5 years

**Condition or service qualifier:** protected externally by a suitable corrosion-resistant coating and used exclusively for non-corrosive gas that is commercially free from corroding components

**Regulation section:** 49 CFR § 180.209

> A cylinder made in conformance with DOT Specifications 4B, 4BA, 4BW, or 4E protected externally by a suitable corrosion-resistant coating and used exclusively for non-corrosive gas that is commercially free from corroding components may be requalified by volumetric expansion testing every 12 years instead of every 5 years.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT Specifications 4B, 4BA, 4BW, or 4E — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A or 3AA

**Test or inspection:** Periodic requalification

**Interval:** every ten years instead of every five years

**Condition or service qualifier:** removed from any cluster, bank, group, rack, or vehicle each time it is filled

**Regulation section:** 49 CFR § 180.209

> A cylinder conforming to specification DOT 3A or 3AA with a water capacity of 56.7 kg (125 lb) or less that is removed from any cluster, bank, group, rack, or vehicle each time it is filled, may be requalified every ten years instead of every five years, provided the cylinder conforms to all of the following conditions:

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 3A or 3AA — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A, 3AA, or 3AL

**Test or inspection:** water-jacket or direct expansion method

**Interval:** 12 years after the original test date and at 12-year intervals thereafter

**Condition or service qualifier:** used as a fire extinguisher

**Regulation section:** 49 CFR § 180.209

> A DOT 3A, 3AA, or 3AL cylinder must be requalified by: (i) The water-jacket or direct expansion method. A requalification must be performed 12 years after the original test date and at 12-year intervals thereafter.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 3A, 3AA, or 3AL — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 4B, 4BA, 4B240ET or 4BW

**Test or inspection:** water-jacket, direct expansion or proof pressure test methods

**Interval:** by the end of 12 years after the original test date and at 12-year intervals thereafter

**Condition or service qualifier:** used as a fire extinguisher, with a water capacity of 5.44 kg (12 pounds) or less

**Regulation section:** 49 CFR § 180.209

> A DOT 4B, 4BA, 4B240ET or 4BW cylinder used as a fire extinguisher may be tested as follows: (i) For a cylinder with a water capacity of 5.44 kg (12 pounds) or less, by the water-jacket, direct expansion or proof pressure test methods as prescribed in CGA C-1. A requalification must be performed by the end of 12 years after the original test date and at 12-year intervals thereafter.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 4B, 4BA, 4B240ET or 4BW — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT 3A, 3A480X, or 4AA480

**Test or inspection:** Periodic requalification

**Interval:** every 10 years instead of every five years

**Condition or service qualifier:** used exclusively for anhydrous ammonia, commercially free from corroding components, and protected externally by a suitable corrosion-resistant coating (such as paint)

**Regulation section:** 49 CFR § 180.209

> A cylinder conforming to specification DOT 3A, 3A480X, or 4AA480 used exclusively for anhydrous ammonia, commercially free from corroding components, and protected externally by a suitable corrosion-resistant coating (such as paint) may be requalified every 10 years instead of every five years.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

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


**Container specification:** DOT 3A, 3AA, 3B, 4BA, or 4BW

**Test or inspection:** Periodic requalification

**Interval:** every 10 years instead of every five years

**Condition or service qualifier:** used exclusively for methyl bromide

**Regulation section:** 49 CFR § 180.209

> A cylinder conforming to specification DOT 3A, 3AA, 3B, 4BA, or 4BW having a service pressure of 300 psig or less and used exclusively for methyl bromide, <https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=d496477211992c9631bc3d13ef381c7e&term_occur=999&term_src=Title:49:Subtitle:B:Chapter:I:Subchapter:C:Part:180:Subpart:C:180.209> liquid ; mixtures of methyl bromide and ethylene dibromide, liquid ; mixtures of methyl bromide and chlorpicrin, liquid ; mixtures of methyl bromide and petroleum solvents, liquid ; or methyl bromide and nonflammable, nonliquefied compressed gas mixtures , liquid ; commercially free of corroding components, and protected externally by a suitable corrosion resistant coating (such as galvanizing or painting) and internally by a suitable corrosion resistant lining (such as galvanizing) may be tested every 10 years instead of every five years, provided a visual internal and external examination of the cylinder is conducted every five years in accordance with CGA Pamphlet C-6.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT 3A, 3AA, 3B, 4BA, or 4BW — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** a specification listed in the table in this paragraph (g)

**Test or inspection:** complete external visual inspection

**Interval:** at five-year intervals after the first inspection

**Condition or service qualifier:** used exclusively in the service indicated

**Regulation section:** 49 CFR § 180.209

> A cylinder conforming to a specification listed in the table in this paragraph (g) and used exclusively in the service indicated may, instead of a periodic hydrostatic test, be given a complete external visual inspection at the time periodic requalification becomes due. External visual inspection must be in conformance with CGA C-6 or C-6.3, as applicable. When this inspection is used instead of hydrostatic testing, subsequent inspections are required at five-year intervals after the first inspection.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

a specification listed in the table in this paragraph (g) — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested


**Container specification:** DOT-3AL cylinders manufactured of 6351-T6 aluminum alloy

**Test or inspection:** requalified and inspected for sustained load cracking

**Condition or service qualifier:** used in self-contained underwater breathing apparatus (SCUBA), self-contained breathing apparatus (SCBA), or oxygen service

**Regulation section:** 49 CFR § 180.209

> DOT-3AL cylinders manufactured of 6351-T6 aluminum alloy. In addition to the periodic requalification and marking described in <https://www.law.cornell.edu/cfr/text/49/180.205> § 180.205 , each cylinder manufactured of aluminum alloy 6351-T6 used in self-contained underwater breathing apparatus (SCUBA), self-contained breathing apparatus (SCBA), or oxygen service must be requalified and inspected for sustained load cracking in accordance with the non-destructive examination method described in the following table.

Source: <https://www.law.cornell.edu/cfr/text/49/180.209>

DOT-3AL cylinders manufactured of 6351-T6 aluminum alloy — How often hazmat cylinders, cargo tanks, IBCs and portable tanks must be retested