CDL Hazmat marking study guide
Subpart D of 49 CFR Part 172 (sections 172.300 to 172.338) says how packages, freight containers and transport vehicles carrying hazardous materials must be marked. This guide sets out what the rule text states on who must mark, the general marking rules, non-bulk and bulk packages, portable tanks and cargo tanks, identification numbers on orange panels, placards and white square-on-point displays, and the inhalation hazard, explosives, limited quantity and marine pollutant marks. Many duties depend on whether a packaging is bulk or non-bulk, on its capacity, and on whether a marking is visible, so the exact words matter. The hazmat (H) endorsement also needs a TSA security threat assessment and a state knowledge test; this guide covers neither and is not that test. Your State may have its own requirements, so check them too. Every point links to the regulation and quotes its exact words.
Who marks and general rules
Each person who offers a hazardous material for transportation must mark each package, freight container and transport vehicle containing it in the manner Subpart D requires.
“Each person who offers a hazardous material for transportation shall mark each package, freight container, and transport vehicle containing the hazardous material in the manner required by this subpart.”
A carrier that transports a hazardous material must do this marking when Subpart D assigns the function to the carrier.
“When assigned the function by this subpart, each carrier that transports a hazardous material shall mark each package, freight container, and transport vehicle containing the hazardous material in the manner required by this subpart.”
No person may offer or transport a package marked with a proper shipping name, an identification number or any other marking showing the material is hazardous (for example RQ or INHALATION HAZARD) unless the package contains that hazardous material or its residue.
“No person may offer for transportation or transport a package which is marked with the proper shipping name, the identification number of a hazardous material or any other markings indicating that the material is hazardous (e.g., RQ, INHALATION HAZARD) unless the package contains the identified hazardous material or its residue.”
One of the listed exceptions: the prohibition does not apply to a package in a transport vehicle or freight container if the package is not visible during transportation and is loaded by the shipper and unloaded by the shipper or consignee.
“Transportation of a package in a transport vehicle or freight container if the package is not visible during transportation and is loaded by the shipper and unloaded by the shipper or consignee.”
Required markings must be durable, in English, and printed on or affixed to the surface of a package or on a label, tag or sign.
“Must be durable, in English and printed on or affixed to the surface of a package or on a label, tag, or sign.”
Required markings must be on a sharply contrasting background, unobscured by labels or attachments, and away from any other marking (such as advertising) that could substantially reduce their effectiveness.
“(2) Must be displayed on a background of sharply contrasting color; (3) Must be unobscured by labels or attachments; and (4) Must be located away from any other marking (such as advertising) that could substantially reduce its effectiveness.”
Non-bulk packages
Except as otherwise provided, the person offering a hazardous material in a non-bulk packaging must mark the package with the proper shipping name and identification number (preceded by "UN", "NA" or "ID", as appropriate) as shown in the 172.101 Hazardous Materials Table.
“Except as otherwise provided by this subchapter, each person who offers a hazardous material for transportation in a non-bulk packaging must mark the package with the proper shipping name and identification number (preceded by “UN”, “NA” or “ID,” as appropriate), as shown in the § 172.101 Hazardous Materials Table.”
49 CFR 172.301, General marking requirements for non-bulk packagings
The identification number marking must be in characters at least 12 mm (0.47 inches) high. Packages with a maximum capacity of 30 liters (8 gallons) or less, 30 kg (66 pounds) maximum net mass, or cylinders with a water capacity of 60 liters (16 gallons) or less need characters at least 6 mm (0.24 inches) high, and packages of 5 liters (1.32 gallons) or less or 5 kg (11 pounds) maximum net mass or less are marked in a size appropriate for the package.
“The identification number marking preceded by “UN”, “NA”, or “ID” as appropriate must be marked in characters at least 12 mm (0.47 inches) high. Packages with a maximum capacity of 30 liters (8 gallons) or less, 30 kg (66 pounds) maximum net mass, or cylinders with a water capacity of 60 liters (16 gallons) or less must be marked with characters at least 6 mm (0.24 inches) high. Packages with a maximum capacity of 5 liters (1.32 gallons) or less or 5 kg maximum net mass (11 pounds) or less must be marked in a size appropriate for the size of the package.”
49 CFR 172.301, General marking requirements for non-bulk packagings
A transport vehicle or freight container holding only a single hazardous material in non-bulk packages must be marked on each side and each end with the material's identification number, subject to the conditions that follow.
“A transport vehicle or freight container containing only a single hazardous material in non-bulk packages must be marked, on each side and each end as specified in the § 172.332 or § 172.336, with the identification number specified for the hazardous material in the § 172.101 Table, subject to the following provisions and limitations:”
49 CFR 172.301, General marking requirements for non-bulk packagings
The conditions: every package has the same proper shipping name and identification number, the aggregate gross weight of the hazardous material is 4,000 kg (8,820 pounds) or more, all of it is loaded at one loading facility, and the vehicle or container holds no other material, hazardous or otherwise.
“Each package is marked with the same proper shipping name and identification number; (ii) The aggregate gross weight of the hazardous material is 4,000 kg (8,820 pounds) or more; (iii) All of the hazardous material is loaded at one loading facility; (iv) The transport vehicle or freight container contains no other material, hazardous or otherwise; and”
49 CFR 172.301, General marking requirements for non-bulk packagings
This large-quantity identification number rule does not apply to Class 1, Class 7, or non-bulk packagings for which identification numbers are not required.
“The identification number marking requirement of this paragraph (a)(3) does not apply to Class 1, Class 7, or to non-bulk packagings for which identification numbers are not required.”
49 CFR 172.301, General marking requirements for non-bulk packagings
The person offering a hazardous material in a non-bulk package must mark it with the name and address of the consignor or consignee, except in one of two cases: the package is transported by highway only and will not be transferred from one motor carrier to another, or it is part of a carload, truckload or freight container load whose entire contents go from one consignor to one consignee.
“Each person who offers for transportation a hazardous material in a non-bulk package shall mark that package with the name and address of the consignor or consignee except when the package is— (1) Transported by highway only and will not be transferred from one motor carrier to another; or (2) Part of a carload lot, truckload lot or freight container load, and the entire contents of the rail car, truck or freight container are shipped from one consignor to one consignee.”
49 CFR 172.301, General marking requirements for non-bulk packagings
A transport vehicle or freight container with a material poisonous by inhalation in non-bulk packages must be marked on each side and each end with its identification number when the material is in Hazard Zone A or B and the vehicle or container is loaded at one facility with 1,000 kg (2,205 pounds) or more aggregate gross weight of it in non-bulk packages with the same proper shipping name and identification number.
“A transport vehicle or freight container containing a material poisonous by inhalation in non-bulk packages shall be marked, on each side and each end as specified in § 172.332 or § 172.336, with the identification number specified for the hazardous material in the § 172.101 table, subject to the following provisions and limitations: (1) The material is in Hazard Zone A or B; (2) The transport vehicle or freight container is loaded at one facility with 1,000 kg (2,205 pounds) or more aggregate gross weight of the material in non-bulk packages marked with the same proper shipping name and identification number; and”
If more than one such material is aboard, the vehicle shows one identification number: for materials in the same hazard zone, that of the material with the greatest aggregate gross weight; for materials in both Hazard Zones A and B, that of the Hazard Zone A material.
“If the transport vehicle or freight container contains more than one material meeting the provisions of this paragraph (c), it shall be marked with the identification number for one material, determined as follows: (i) For different materials in the same hazard zone, with the identification number of the material having the greatest aggregate gross weight; and (ii) For different materials in both Hazard Zones A and B, with the identification number for the Hazard Zone A material.”
Hazard-specific package marks
Except as the section provides, each non-bulk combination package with inner packagings of liquid hazardous materials, each single packaging fitted with vents, and each open cryogenic receptacle for refrigerated liquefied gases must be packed with closures upward and legibly marked with orientation markings on two opposite vertical sides, arrows pointing in the correct upright direction.
“Except as provided in this section, each non-bulk combination package having inner packagings containing liquid hazardous materials, single packaging fitted with vents, or open cryogenic receptacle intended for the transport of refrigerated liquefied gases must be: (1) Packed with closures upward, and (2) Legibly marked with package orientation markings that are similar to the illustration shown in this paragraph, on two opposite vertical sides of the package with the arrows pointing in the correct upright direction.”
49 CFR 172.312, Liquid hazardous materials in non-bulk packagings
The orientation rule does not apply to a non-bulk package whose inner packagings are cylinders, or, except when offered or intended for transportation by aircraft, to packages of flammable liquids in inner packagings of 1 L or less prepared under 173.150(b) or (c). The section lists further exceptions.
“The requirements of paragraph (a) of this section do not apply to— (1) A non-bulk package with inner packagings which are cylinders. (2) Except when offered or intended for transportation by aircraft, packages containing flammable liquids in inner packagings of 1 L or less prepared in accordance with § 173.150 (b) or (c) of this subchapter.”
49 CFR 172.312, Liquid hazardous materials in non-bulk packagings
Each non-bulk plastic outer packaging used as a single or composite packaging for Division 6.1 materials must be permanently marked (embossed or by other durable means) with the word POISON in letters at least 6.3 mm (0.25 inch) high, located within 150 mm (6 inches) of the closure.
“Each non-bulk plastic outer packaging used as a single or composite packaging for materials meeting the definition of Division 6.1 (in § 173.132 of this subchapter) shall be permanently marked, by embossment or other durable means, with the word “POISON” in letters at least 6.3 mm (0.25 inch) in height. Additional text or symbols related to hazard warning may be included in the marking. The marking shall be located within 150 mm (6 inches) of the closure of the packaging.”
For each non-bulk package containing a hazardous substance, two rules apply. First, if the proper shipping name does not name the hazardous substance, its name must be marked in parentheses with the proper shipping name (at least two, including the two with the lowest RQs, when there are two or more); this first rule excepts radioactive material packages labeled under 172.403. Second, the letters RQ must be marked with the proper shipping name.
“For each non-bulk package that contains a hazardous substance— (a) Except for packages of radioactive material labeled in accordance with § 172.403, if the proper shipping name of a material that is a hazardous substance does not identify the hazardous substance by name, the name of the hazardous substance must be marked on the package, in parentheses, in association with the proper shipping name. If the material contains two or more hazardous substances, at least two hazardous substances, including the two with the lowest reportable quantities (RQs), must be identified. For a hazardous waste, the waste code (e.g., D001), if appropriate, may be used to identify the hazardous substance. (b) The letters “RQ” must be marked on the package in association with the proper shipping name.”
A material poisonous by inhalation must be marked "Inhalation Hazard" in association with the required labels or placards and the shipping name when required; on a bulk packaging the marking goes on two opposing sides.
“A material poisonous by inhalation (see § 171.8 of this subchapter) shall be marked “Inhalation Hazard” in association with the required labels or placards, as appropriate, and shipping name when required. The marking must be on two opposing sides of a bulk packaging.”
When the words "Inhalation Hazard" appear on the label or placard, the separate "Inhalation Hazard" marking is not required on the package.
“When the words “Inhalation Hazard” appear on the label, as prescribed in §§ 172.416 and 172.429, or placard, as prescribed in §§ 172.540 and 172.555, the “Inhalation Hazard” marking is not required on the package.”
Except as paragraphs (b) through (e) provide, each package containing a Class 1 material must be marked with the EX-number for each substance, article or device in it.
“Except as otherwise provided in paragraphs (b), (c), (d) and (e) of this section, each package containing a Class 1 material must be marked with the EX-number for each substance, article or device contained therein.”
The EX-number marking requirements do not apply if the EX number, FC number, product code or national stock number of each explosive item is shown with the shipping description required by 172.202(a).
“The requirements of this section do not apply if the EX number, FC number, product code or national stock number of each explosive item described under a proper shipping description is shown in association with the shipping description required by § 172.202(a).”
Bulk packages
Except as otherwise provided, no one may offer or transport a hazardous material in a bulk packaging unless it shows the identification number: on each side and each end if its capacity is 3,785 L (1,000 gallons) or more; on two opposing sides if less; and, for cylinders permanently installed on a tube trailer, on each side and each end of the motor vehicle.
“Except as otherwise provided in this subpart, no person may offer for transportation or transport a hazardous material in a bulk packaging unless the packaging is marked as required by § 172.332 with the identification number specified for the material in the § 172.101 table— (1) On each side and each end, if the packaging has a capacity of 3,785 L (1,000 gallons) or more; (2) On two opposing sides, if the packaging has a capacity of less than 3,785 L (1,000 gallons); or (3) For cylinders permanently installed on a tube trailer motor vehicle, on each side and each end of the motor vehicle.”
49 CFR 172.302, General marking requirements for bulk packagings
Except as otherwise provided, markings on bulk packagings must be at least 6.0 mm wide and at least 100 mm high on rail cars; at least 4.0 mm wide and at least 12 mm high on portable tanks under 3,785 L (1,000 gallons); at least 4.0 mm wide with a height of 25 mm (one inch) on IBCs; and at least 6.0 mm (0.24 inch) wide and at least 50 mm (2.0 inches) high on cargo tanks and other bulk packagings.
“Except as otherwise provided, markings required by this subpart on bulk packagings must— (1) Have a width of at least 6.0 mm (0.24 inch) and a height of at least 100 mm (3.9 inches) for rail cars; (2) Have a width of at least 4.0 mm (0.16 inch) and a height of at least 12 mm (0.47 inch) for portable tanks with capacities of less than 3,785 L (1,000 gallons) and a width of at least 4.0 mm (0.16 inch) and a height of 25 mm (one inch) for IBCs; and (3) Have a width of at least 6.0 mm (0.24 inch) and a height of at least 50 mm (2.0 inches) for cargo tanks and other bulk packagings.”
49 CFR 172.302, General marking requirements for bulk packagings
A bulk packaging marked with a proper shipping name, common name or identification number must stay marked when emptied, unless one of the options applies: it is sufficiently cleaned of residue and purged of vapors to remove any potential hazard, or it is refilled with a material requiring different or no markings so that any residue is no longer hazardous.
“Each bulk packaging marked with a proper shipping name, common name or identification number as required by this subpart must remain marked when it is emptied unless it is— (1) Sufficiently cleaned of residue and purged of vapors to remove any potential hazard; or (2) Refilled, with a material requiring different markings or no markings, to such an extent that any residue remaining in the packaging is no longer hazardous.”
49 CFR 172.302, General marking requirements for bulk packagings
A rail car, freight container, truck body or trailer whose lading has been fumigated with any hazardous material, or is undergoing fumigation, must be marked as specified in 173.9.
“A rail car, freight container, truck body or trailer in which the lading has been fumigated with any hazardous material, or is undergoing fumigation, must be marked as specified in § 173.9 of this subchapter.”
49 CFR 172.302, General marking requirements for bulk packagings
Except as paragraph (b) provides, a bulk packaging containing an elevated temperature material must be marked on two opposing sides with the word HOT in black or white Gothic lettering on a contrasting background, either on the packaging itself or in black lettering on a plain white square-on-point the size of a placard.
“Except as provided in paragraph (b) of this section, a bulk packaging containing an elevated temperature material must be marked on two opposing sides with the word “HOT” in black or white Gothic lettering on a contrasting background. The marking must be displayed on the packaging itself or in black lettering on a plain white square-on-point configuration having the same outside dimensions as a placard.”
Bulk packagings containing molten aluminum or molten sulfur must be marked MOLTEN ALUMINUM or MOLTEN SULFUR, in the same manner as the HOT marking.
“Bulk packagings containing molten aluminum or molten sulfur must be marked “MOLTEN ALUMINUM” or “MOLTEN SULFUR”, respectively, in the same manner as prescribed in paragraph (a) of this section.”
Portable tanks, IBCs and other bulk packagings
No one may offer or transport a portable tank containing a hazardous material unless it is legibly marked on two opposing sides with the proper shipping name. For vessel transportation the name must be at least 65 mm (2.5 inches) high, or not less than 12 mm (0.47 inches) on portable tanks under 3,000 L (792.52 gallons).
“No person may offer for transportation or transport a portable tank containing a hazardous material unless it is legibly marked on two opposing sides with the proper shipping name specified for the material in the § 172.101 table. For transportation by vessel, the minimum height for a proper shipping name marked on a portable tank is 65 mm (2.5 inches); except that portable tanks with a capacity of less than 3,000 L (792.52 gallons) may reduce the marking size to not less than 12 mm (0.47 inches).”
If the portable tank's identification numbers are not visible, the transport vehicle or freight container carrying it must be marked on each side and each end with the identification number.
“If the identification number markings required by § 172.302(a) are not visible, a transport vehicle or freight container used to transport a portable tank containing a hazardous material must be marked on each side and each end as required by § 172.332 with the identification number specified for the material in the § 172.101 table.”
The person who offers a portable tank of hazardous material to a motor carrier must give the motor carrier the identification numbers on placards, orange panels or the white square-on-point display, as appropriate, for each side and end of the vehicle or container from which the tank's numbers are not visible.
“Each person who offers a portable tank containing a hazardous material to a motor carrier, for transportation in a transport vehicle or freight container, shall provide the motor carrier with the required identification numbers on placards, orange panels, or the white square-on-point configuration, as appropriate, for each side and each end of the transport vehicle or freight container from which identification numbers on the portable tank are not visible.”
For other bulk packagings (such as an IBC) in or on a transport vehicle or freight container, if the packaging's identification number is not visible, the vehicle or container must be marked on each side and each end with the identification number.
“For a bulk packaging contained in or on a transport vehicle or freight container, if the identification number marking on the bulk packaging (e.g., an IBC) required by § 172.302(a) is not visible, the transport vehicle or freight container must be marked as required by § 172.332 on each side and each end with the identification number specified for the material in the § 172.101 table.”
Transport vehicles or freight containers carrying empty IBCs under 173.29(d) are not subject to identification number marking requirements.
“Transport vehicles or freight containers used to transport empty IBCs in accordance with § 173.29(d) of this subchapter are not subject to identification number marking requirements.”
Cargo tanks
Unless the cargo tank is already marked, a person who offers a hazardous material to a motor carrier for transportation in a cargo tank must give the motor carrier the identification numbers on placards, or affix orange panels with the numbers, before or at the time the material is offered.
“Unless a cargo tank is already marked with the identification numbers required by this subpart, the identification numbers must be provided or affixed as follows: (1) A person who offers a hazardous material to a motor carrier for transportation in a cargo tank shall provide the motor carrier the identification numbers on placards or shall affix orange panels containing the required identification numbers, prior to or at the time the material is offered for transportation.”
Under the same paragraph (which applies unless the cargo tank is already marked with the required identification numbers), a person who offers a cargo tank containing a hazardous material for transportation must affix the identification numbers on panels or placards before or at the time the cargo tank is offered.
“A person who offers a cargo tank containing a hazardous material for transportation shall affix the required identification numbers on panels or placards prior to or at the time the cargo tank is offered for transportation.”
A further rule covers a cargo tank carried on or in a transport vehicle or freight container when the tank's identification number marking would not normally be visible during transportation. The next point says what applies in that case.
“(3) For a cargo tank transported on or in a transport vehicle or freight container, if the identification number marking on the cargo tank required by § 172.302(a) would not normally be visible during transportation—”
In that case, the transport vehicle or freight container must be marked on each side and each end with the identification number; and when the cargo tank is permanently installed within an enclosed cargo body, the tank's own identification number need only be shown on each side and end of the tank that is visible when the tank is accessed.
“The transport vehicle or freight container must be marked as required by § 172.332 on each side and each end with the identification number specified for the material in the § 172.101 table; and (ii) When the cargo tank is permanently installed within an enclosed cargo body of the transport vehicle or freight container, the identification number marking required by § 172.302(a) need only be displayed on each side and end of a cargo tank that is visible when the cargo tank is accessed.”
Except for certain nurse tanks, each cargo tank transporting a Class 2 material must be marked on each side and each end, in lettering no less than 50 mm (2.0 inches), with one of the options: the proper shipping name of the gas, or an appropriate common name (for example "Refrigerant Gas").
“Except for certain nurse tanks which must be marked as specified in § 173.315(m) of this subchapter, each cargo tank transporting a Class 2 material subject to this subchapter must be marked, in lettering no less than 50 mm (2.0 inches), on each side and each end with— (1) The proper shipping name specified for the gas in the § 172.101 table; or (2) An appropriate common name for the material (e.g., “Refrigerant Gas”).”
After October 3, 2005, each on-vehicle manually-activated remote shutoff device for closing the internal self-closing stop valve must be marked "Emergency Shutoff" in letters at least 0.75 inches high, in a contrasting color, immediately next to the means of closure.
“After October 3, 2005, each on-vehicle manually-activated remote shutoff device for closure of the internal self-closing stop valve must be identified by marking “Emergency Shutoff” in letters at least 0.75 inches in height, in a color that contrasts with its background, and located in an area immediately adjacent to the means of closure.”
Identification numbers are not required on cargo tanks that contain only gasoline when the alternative in the table is met: the tank is marked "Gasoline" on each side and rear in letters no less than 50 mm (2 inches) high, or is placarded under 172.542(c).
“The tank is marked “Gasoline” on each side and rear in letters no less than 50 mm (2 inches) high or is placarded in accordance with § 172.542(c).”
Identification number displays
When Subpart D requires identification number markings, they must be shown on orange panels or placards as 172.332 specifies, or on white square-on-point displays as 172.336(b) prescribes.
“When required by § 172.301, § 172.302, § 172.313, § 172.326, § 172.328, § 172.330, or § 172.331, identification number markings must be displayed on orange panels or placards as specified in this section, or on white square-on-point configurations as prescribed in § 172.336(b).”
An identification number may be shown only on a placard corresponding to the primary hazard class of the material.
“An identification number may be displayed only on a placard corresponding to the primary hazard class of the hazardous material.”
No person may show an identification number on a RADIOACTIVE, EXPLOSIVES 1.1, 1.2, 1.3, 1.4, 1.5 or 1.6, DANGEROUS, or subsidiary hazard placard.
“No person may display an identification number on a RADIOACTIVE, EXPLOSIVES 1.1, 1.2, 1.3, 1.4, 1.5 or 1.6, DANGEROUS, or subsidiary hazard placard.”
Except as 172.338 provides, an identification number may not be shown on an orange panel on a cargo tank unless the person offering the hazardous material in the cargo tank affixed it.
“Except as specified in § 172.338, an identification number may not be displayed on an orange panel on a cargo tank unless affixed to the cargo tank by the person offering the hazardous material for transportation in the cargo tank.”
Where identification numbers are required but may not go on the placards authorized for the material, they must be shown on orange panels or plain white square-on-point displays in association with the required placards. A white square-on-point display with an identification number is not considered a placard.
“In addition, for materials in hazard classes for which placards are specified and identification number displays are required, but for which identification numbers may not be displayed on the placards authorized for the material (see § 172.334(a)), identification numbers must be displayed on orange panels or on the plain white square-on-point display configuration in association with the required placards. An identification number displayed on a white square-on-point display configuration is not considered to be a placard.”
If more than one required identification number display is lost, damaged or destroyed during transportation, the carrier must replace all the missing or damaged numbers as soon as practicable.
“If more than one of the identification number markings on placards, orange panels, or white square-on-point display configurations that are required to be displayed are lost, damaged or destroyed during transportation, the carrier shall replace all the missing or damaged identification numbers as soon as practicable.”
In that case the correct numbers may be entered by hand on the placard, orange panel or white square-on-point display, legibly and with indelible marking material, inside the white display area specified in 172.332.
“However, in such a case, the numbers may be entered by hand on the appropriate placard, orange panel or white square-on-point display configuration providing the correct identification numbers are entered legibly using an indelible marking material. When entered by hand, the identification numbers must be located in the white display area specified in § 172.332.”
Limited quantity and marine pollutant marks
Except for Class 7 articles or substances prepared under subpart I of part 173, a limited quantity package offered by a mode other than air must show the limited quantity marking. A package with this mark is not subject to the 172.301 marking requirements unless it also contains a hazardous substance or a hazardous waste.
“Except for an article or substance of Class 7 prepared in accordance with subpart I of part 173, a package prepared in accordance with applicable limited quantity requirements in part 173 of this subchapter and offered for transportation by a mode other than air must display the limited quantity marking shown in paragraph (a)(1) of this section. A package displaying this mark is not subject to the marking requirements of § 172.301 of this subpart unless the limited quantity package also contains a hazardous substance or a hazardous waste.”
The limited quantity mark must be durable, legible, of a size relative to the packaging, readily visible, and applied on at least one side or one end of the outer packaging.
“The square-on-point must be durable, legible and of a size relative to the packaging, readily visible, and must be applied on at least one side or one end of the outer packaging.”
For highway transportation by private motor carrier, except for Class 1 and 7 and Divisions 6.1 and 6.2, the limited quantity marking is not required on a package of Packing Group II and III materials prepared under the limited quantity rules of subpart B of part 173, provided the conditions that follow are met.
“Except for Class 1 and 7, and Division 6.1 and 6.2 materials, for highway transportation by private motor carrier, the limited quantity marking is not required to be displayed on a package containing materials assigned to Packing Group II and III prepared in accordance with the limited quantity requirements in subpart B of part 173 of this subchapter provided:”
The conditions: liquid inner packagings do not exceed 1.0 L (0.3 gallons) each and solid inner packagings 1.0 kg (2.2 pounds) each; no more than 2 L (0.6 gallons) or 2 kg (4.4 pounds) aggregate net quantity of any one hazardous material per vehicle; total gross weight of all limited quantity packages per vehicle not over 60 kg (132 pounds); and each package marked with the offeror's name and address, a 24-hour emergency response telephone number and "Contains Chemicals" in letters at least 25 mm (one inch) high on a contrasting background.
“Inner packagings for liquid hazardous materials do not exceed 1.0 L (0.3 gallons) net capacity each; (ii) Inner packagings for solid hazardous materials do not exceed 1.0 kg (2.2 pounds) net capacity each; (iii) No more than 2 L (0.6 gallons) or 2 kg (4.4 pounds) aggregate net quantity of any one hazardous material is transported per vehicle; (iv) The total gross weight of all the limited quantity packages per vehicle does not exceed 60 kg (132 pounds); and (v) Each package is marked with the name and address of the offeror, a 24-hour emergency response telephone number and the statement “Contains Chemicals” in letters at least 25 mm (one-inch) high on a contrasting background.”
Except as otherwise provided, a bulk packaging containing a marine pollutant with a capacity of less than 3,785 L (1,000 gallons) must show the MARINE POLLUTANT mark on at least two opposing sides or two ends other than the bottom, visible from the direction it faces.
“Except as otherwise provided in this subchapter, a bulk packaging that contains a marine pollutant must— (1) Be marked with the MARINE POLLUTANT mark on at least two opposing sides or two ends other than the bottom if the packaging has a capacity of less than 3,785 L (1,000 gallons). The mark must be visible from the direction it faces.”
A transport vehicle or freight container holding a package that needs the MARINE POLLUTANT mark must show the mark on each side and each end, visible from the direction it faces; the marking shown on a freight container or portable tank loaded on a motor vehicle or rail car may meet this.
“A transport vehicle or freight container that contains a package subject to the marking requirements of paragraph (a) or (b) of this section must be marked with the MARINE POLLUTANT mark. The mark must appear on each side and each end of the transport vehicle or freight container, and must be visible from the direction it faces. This requirement may be met by the marking displayed on a freight container or portable tank loaded on a motor vehicle or rail car.”
The MARINE POLLUTANT mark is not required on single or combination packagings where each single package or each inner packaging holds a net quantity of 5 L (1.3 gallons) or less for liquids or a net mass of 5 kg (11 pounds) or less for solids; on a combination packaging of a marine pollutant other than a severe marine pollutant in inner packagings each holding 5 L (1.3 gallons) or less for liquids or 5 kg (11 pounds) or less for solids; except for vessel transport, on a bulk packaging, freight container or transport vehicle bearing a label or placard specified in subparts E or F; or on a limited quantity package marked under 172.315.
“The MARINE POLLUTANT mark is not required— (1) On single packagings or combination packagings where each single package or each inner packaging of combination packagings has: (i) A net quantity of 5 L (1.3 gallons) or less for liquids; or (ii) A net mass of 5 kg (11 pounds) or less for solids (2) On a combination packaging containing a marine pollutant, other than a severe marine pollutant, in inner packagings each of which contains: (i) 5 L (1.3 gallons) or less net capacity for liquids; or (ii) 5 kg (11 pounds) or less net capacity for solids. (3) Except for transportation by vessel, on a bulk packaging, freight container or transport vehicle that bears a label or placard specified in subparts E or F of this part. (4) On a package of limited quantity material marked in accordance with § 172.315 of this part.”
Not covered here
The marine pollutant marks for non-bulk packages in vessel transportation (172.322(a)), the air-only limited quantity and KEEP AWAY FROM HEAT marks (172.315(b), 172.317), Class 7 package marks (172.310), tank car marks (172.330) and the mark sizes and designs are not covered in detail; read them in the regulation. We only write what an official source states, so study these parts with your certifying program's materials.
Sources
- eCFR: 49 CFR 172.300, Applicability (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.303, Prohibited marking (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.304, Marking requirements (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.301, General marking requirements for non-bulk packagings (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.313, Poisonous hazardous materials (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.312, Liquid hazardous materials in non-bulk packagings (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.324, Hazardous substances in non-bulk packagings (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.320, Explosive hazardous materials (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.302, General marking requirements for bulk packagings (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.325, Elevated temperature materials (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.326, Portable tanks (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.331, Bulk packagings other than portable tanks, cargo tanks, tank cars and multi-unit tank car tanks (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.328, Cargo tanks (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.336, Identification numbers; special provisions (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.332, Identification number markings (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.334, Identification numbers; prohibited display (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.338, Replacement of identification numbers (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.315, Limited quantities (as of Nov 4, 2026)Checked November 6, 2026
- eCFR: 49 CFR 172.322, Marine pollutants (as of Nov 4, 2026)Checked November 6, 2026
Other CDL study guides: License standards, Driver qualifications, Driving rules, Hours of service, Inspection and maintenance, Brakes, Cargo securement, Drug and alcohol testing, Hazmat classes and definitions, Hazmat shipping papers and emergency information, Hazmat placarding, Hazmat highway carriage, loading and segregation, Hazmat driving, parking and training