Standards & Specifications Page 1 of 10

Table of Contents

Hazmat Basics ......................................................................................... Pg. 1

Package Marks and Design Types ............................................................... Pg. 4

Drum Reconditioning ................................................................................. Pg. 6

Intermediate Bulk Containers ...................................................................... Pg. 7

Closure Notifications ................................................................................. Pg. 9

Minimum Drum Thickness for Reconditioning ................................................. Pg. 9

Hazmat Basics

Contents:

• Bulk, Non-Bulk and Intermediate Bulk Containers

• The Hazardous Materials Table

• Classes of Hazardous Materials 1-9

• DOT Packing Groups I, II, III

• Hazard Levels X, Y, Z

• Proper Shipping Name / UN Number

• Package Labels

• Vehicle Placards

• Shipping Papers

Bulk, Non-bulk and Intermediate Bulk Containers

• Bulk containers are those greater that 119 gallons.

• Non-bulk containers are 119 gallons or less; also, those used for solids may carry up to 400 kg 

net mass.

•Intermediate Bulk Containers are often referred to as“IBCs”; typically 260-300 gallons; some 

regulations are written specifically for IBCs 

Standards and Specifications
Standards & Specifications Page 2 of 10

The Hazardous Materials Table

Found in the regulations, the table contains:

• A Material’s Hazard Class 

• The material’s “Proper Shipping Name” 

• 4-Digit UN Number

• Packing Group I,II, or III

• Packaging Authorizations, and

• Special Instructions (where applicable)

Classes of Hazardous Materials

– There are 9 Classes of Hazardous Materials.

– A material’s classification is a key consideration in how the material must be packaged, 

marked, labeled, shipped and handled.

DOT Classifications and Divisions

• Class 1 - Explosives

• Class 2 - Gases

– Division 2.2 - Non-flammable Gas 

– Division 2.1 - Flammable Gases 

– Division 2.3 - Poisonous Gas 

• Class 3 - Flammable Liquid (flash point < 141oF)

Combustible Liquid (flash point 141 - 200oF)

• Class 4 - Solids 

Division 4.1 - Flammable Solids

Division 4.2 - Spontaneously Combustible

Division 4.3 - Dangerous When Wet

• Class 5 - Oxidizers and Peroxides

– Division 5.1 - Oxidizers (can cause other materials in contact to burn more rapidly)

– Division 5.2 - Organic peroxides (can easily burn or explode)

• Class 6 - Toxic and Infectious

– Division 6.1 - Toxics (poisonous)

– Division 6.2 - Infectious Substances

• Class 7 – Radioactive

• Class 8 - Corrosive 

• Class 9 - Miscellaneous Hazard (present a hazard, such as pollution, that doesn’t fall within 

any other classification)
Standards & Specifications Page 3 of 10

DOT Packing Groups

A hazardous material’s Packing Group reflects the level of hazard and determines the mark 

required on the packaging.

Packing Group Degree of Hazard Packaging Mark

I most serious X

II moderate hazard Y

III low hazard Z

Package Labels

• Diamond-shaped; they communicate the hazard with text and images. Examples:

Vehicle Placards

• Similar to package labels, but larger.

• Appear on all sides of vehicles carrying hazmat (1,000 lbs or more for most materials).

• Trailers with only empty drums & pails headed for reconditioning are exempt from placards.

• Currently, empty IBCs not exempt; remember to remove vehicle placards when empty IBCs 

are unloaded.

Shipping Papers

• Not required for empty drums & pails shipped by contract carrier or on reconditioner's trucks for 

reuse or reconditioning.

• Required for empty IBCs.

• Offer shipping papers to law enforcement when asked.

• Driver must keep shipping papers in cab of vehicle.
Standards & Specifications Page 4 of 10

Package Markings and Design Types

A three-part code indicates the type of packaging.

Thus, "1A1" is a closed-head steel drum; “1H2" is an open-head plastic drum, etc.

Markings (Example: liquids drum)

Markings (Example: solids drum) [next page]

1A1/Y 1.2/100

01/USA/xxxx

u

n

Packing Group

Specific Gravity of 

Liquid

Vapor pressure 

of Liquid (kPa)

Manufacturer DOT 

Registration Number

Country of 

Manufacture

Year of Manufacture

UN Symbol

1=drum

A=steel

1=Tight Head

A. Steel

B. Aluminum

C. Wood

G. Fibre

H. Plastic

1. Drums

2. Barrels

3. Jerricans

4. Boxes

5 Bags

6. Composite

1. Closed Head

2. Open Head
Standards & Specifications Page 5 of 10

Markings (Example: solids drum)

Durable Label or Stencil on Side

For Liquids:

For Solids:

Bottom embossment for steel drums

• Bottom must be permanently marked (embossed) with “birth certificate”

Example: UN 1A1 / Y 1.4 / 200 / 98

1.2 0.9 1.2

• 1.2/0.9/1.2 is thickness in mm (top, body, bottom)

• Would be simply “1.0” for an “all-1 mm” drum

1A1/Y1.2/100 (“first line mark”)

01/USA/xxxx (“second line mark”)

u

n

1A2/Y400/S (“first line mark”)

01/USA/xxxx (“second line mark”)

u

n

1H2 /X 400/ S

01/USA/xxxx 

Country of 

Manufacture

Manufacturer DOT 

Registration Number

“S” Indicates 

Solids 

Maximum Gross 

Mass (kg)

u

n

Packing Group

Year of Manufacture

1=Drum

H=Plastic

2=Open Head

UN Symbol
Standards & Specifications Page 6 of 10

Drum Reconditionin g

 De-labeling

 Chaining / shot blast (for steel)

 Wash or burn

 Painting / lining

 Leakproofness test

 Marking / labeling

Reconditioners’ Markings

• Durable side mark (e.g. label or stencil)

• Re-applied by reconditioner

• Same as manufacturer’s mark but

must also show:

country code; reconditioner’s address or

registered symbol or number; year (last

two digits); “R” (reconditioned); “L”

(leakproof tested).

Example: Reconditioner’s Durable Mark (tight-head drum/ liquids)

1A1/Y1.2/100

USA/M-xxxx/01 RL

Drum Remanufacturing

• Rebuilding tight-head drums

• Converting tight-head drums to 

open-head drums

• Converting non-UN drums to UN-type

hazmat drums

• Remanufacturing triggers the requirements

for design-type testing

“R” indicates reconditioned

“L” indicates leakproof tested
Standards & Specifications Page 7 of 10

Intermediate Bulk Containers (IBCs)

• Flexible or rigid IBCs

• Some are all metal or all plastic

• Composite IBCs : “Bottle in a Cage”

• Typically 260 – 300 gallons

• IBCs have separate, but similar, hazmat rules

Marks for Composite IBCs

• UN symbol 

• 21HA1 (solids) or 31HA1 (liquids)

“H” indicates IBC; “A” indicates composite

• X, Y, or Z Packing Group

• Month and last two digits of year of

manufacture or remanufacture

• Country (USA)

• Name or symbol of manufacturer or 

remanufacturer

• Stacking test load, in kilograms

• Maximum permissible gross mass, kilograms

• Capacity in liters

• Tare mass, kilograms

• Hydraulic test pressure, kPa

• Maximum filling/discharge pressure.

• Body material and minimum thickness in mm

• Date of last leakproofness test for liquids 

• Month and year of last inspection

IBC Mark (Example)

UN 31HA1 / Y/12 01/USA/ M1234

4067 kg/1066kg/1070L/73kg

100 kpa/12 01/12 01

Note: December ’01 (12 01) is date of last leakproofness test, and last complete inspection.
Standards & Specifications Page 8 of 10

Composite IBC: Inner Bottle Marks

New bottles should come already marked with: 

• Name or symbol of bottle manufacturer 

• Month and year of bottle manufacture 

• Country of bottle manufacture 

Leaktesting IBCs

• IBCs intended for hazmat liquids (or solids discharged under pressure) must be inspected and 

leak tested every 2 1⁄2 years.

• All IBCs must be internally inspected at least every 5 years 

“Routine Maintenance” of IBCs

• Cleaning.

• Removal and reinstallation or replacement of

body closures and gaskets, or service

equipment meeting the original manufacturer's 

design type (Note: verify leaktightness of 

reinstalled or replaced closures and service

equipment; full leakproofness test not 

required).

• Restoration of structural parts such as legs and

lifting attachment .

Marking on Routinely Maintained Composite IBCs

• Country code

• Name, registered symbol or registered

number of company maintaining the IBC 

Note: This marking for routine maintenance is a condition of RIPA’s IBC Code of Operating 

Practice, as well as a UN recommendation; however, marking IBCs for routine maintenance is not 

currently a regulatory requirement of the U.S. DOT.

“Repair” of Composite IBCs

• The repair of rigid plastic IBCs and inner

plastic bottles is not authorized

• Replace damaged bottles with new bottles

conforming to the original IBC manufacturer's

specification

• Conduct leakproofness test on repaired IBCs

(New, replacement bottles should come already tested!)

• Record the test 
Standards & Specifications Page 9 of 10

Marking on Repaired Composite IBCs

• Mark applied by the company that tests and

inspects the repaired IBC

Country;

Name or symbol of the company

performing the repair;

Month and year of tests and inspections.

Remanufacture of Composite IBCs

• Any change to the IBC design type is remanufacturing.

• The design type of the remanufactured IB must be tested as if it were a new IBC.

• Prepare a full design qualification test report.

• Repeat design qualification tests and prepare a report at least annually for each design type.

• Mark the remanufactured IBC with the same information required on a new IBC of the same 

type.

Closure Notifications

All suppliers of hazmat packagings (including reconditioners) must provide users with written 

instructions on closing the packagings in the same manner as “proto-types” were closed for 

testing and certification.

Typically, written closure instructions can be obtained from the manufacturers of packagings or 

closures.

Minimum Thickness for Reconditioning in U.S.

• Steel drums (55 gallon): 1.2 / 0.9 / 1.2 mm or “all-1.0” mm throughout.

• Steel drums marked 1.1 / 0.8 / 1.1 may not meet minimums .

• Plastic Drums (55 gallon): 2.2mm

U.S. Minimum Thickness Requirements for Steel Drum Reconditioning

Thinner Drums May Not be Reconditionable

U.S. DOT states that a non-bulk packaging used for hazardous materials more than one time 

must meet a series of requirements, one of which is minimum thickness. Minimum thickness 

standards do not apply to drums used for non-hazardous materials. (continued next page)
Standards & Specifications Page 10 of 

10

Steel drums’ minimum thickness standards are set forth in a table with footnotes found in 49 CFR 

173.28(4). The table lists seven packaging sizes from 20 liters to 450 liters. The applicable size 

for 55-gallon drums is 220 liters. 

The table shows that a 55-gallon drum must be at least 0.92 millimeters thick throughout. For 

drums with different thicknesses in body and heads, a footnote reads:

.....Metal drums or jerricans manufactured and marked on or after January 1, 1997, and 

intended for reuse, must be constructed with a minimum thickness of 0.82 mm body and 

1.11 mm heads. 

These DOT minimums specify the actual minimum steel thicknesses, rather than a drum’s 

marked nominal thickness. 

A drum’s marked nominal thickness indicates a theoretical thickness midpoint from which actual 

thickness will vary. Nominal marks are used because no steel mill can roll a perfect sheet of 

steel. There will always be thickness variations, particularly out towards the edges of the sheet.

Permissible variances (i.e., “tolerances”) in steel thickness have been recognized in international 

standards and the U.S. hazardous materials regulations. Steel used in the manufacture of a 

drum marked 0.8 may vary in actual thickness from 0.73 to 0.87 mm (+/- 0.07). Obviously, then, 

there will be some doubt as to whether a drum body marked “0.8” will meet the DOT minimum of 

0.82 mm. (Steel marked 1.1 or 1.2 may vary in actual thickness +/- 0.09 mm.)

Reconditioners prefer a drum that will in all cases meet the minimum actual thickness 

requirements of DOT. Such drums are marked either 1.0 mm (throughout) or 1.2/0.9/1.2 

(top/body/bottom). Of course, drums marked with even thicker walls and heads are also 

acceptable. 

Drums marked 1.1/0.8/1.1 cannot be presumed to meet DOT ‘s minimum thickness requirements 

for reuse. Their actual thicknesses may fall outside the DOT’s minimum for actual thickness. 

And drums marked simply “0.8” (throughout) obviously will not meet the 0.92 mm minimum. 

Tolerances (Variances) for Nominal Steel Drum Marks (mm)