UN1005 anhydrous ammonia table entries.

Where UN1005 sits in the table

Most UN numbers have one row per packing group. UN1005 is different: it has two rows that differ by the symbol in column 1. 172.101(b)(3) says the letter "D" identifies proper shipping names appropriate for describing materials for domestic transportation but possibly inappropriate for international transportation. 172.101(b)(5) says the letter "I" identifies proper shipping names appropriate for international transportation, and that an alternate name may be selected when only domestic transportation is involved. In the eCFR table the I row is Division 2.3 with labels "2.3, 8" and special provision 4, and the D row is Division 2.2 with label "2.2" and special provision 13.

Special provision 4 reads: "This material is poisonous by inhalation (see 171.8 of this subchapter) in Hazard Zone D (see 173.116(a) of this subchapter), and must be described as an inhalation hazard under the provisions of this subchapter." Special provision 13 requires the words "Inhalation Hazard" on each shipping paper in association with the shipping description, on each non-bulk package in association with the proper shipping name and identification number, and on two opposing sides of each bulk package. The regulation text of both provisions is on this page below.

The full rows from the eCFR copy of the table, current through October 29, 2026 and read November 2, 2026, are below. Every value is copied from 49 CFR 172.101; the last column is the regulation's own explanation of the column.

The 172.101 rows, column by column

How the regulation defines the hazard class

173.115(c) says, abridged: "a gas poisonous by inhalation (Division 2.3) means a material which is a gas at 20 °C (68 °F) or less and a pressure of 101.3 kPa (14.7 psia) and which is known to be so toxic to humans as to pose a hazard to health during transportation, or, in the absence of adequate data on human toxicity, is presumed to be toxic to humans because when tested on laboratory animals it has an LC50 value of not more than 5000 mL/m3."

173.115(b) says, abridged: "a non-flammable, nonpoisonous compressed gas (Division 2.2) means any material (or mixture) which exerts in the packaging a gauge pressure of 200 kPa (29.0 psig/43.8 psia) or greater at 20 °C (68 °F), is a liquefied gas or is a cryogenic liquid, and does not meet the definition of Division 2.1 or 2.3."

Special provisions on this entry, in the rule's words

Column 7 does not explain itself; each code is defined in 172.102. These are the definitions as printed in the eCFR text for the codes listed on the rows. Where a provision ends with a list of conditions that this page does not reproduce, it says so.

• 4 (symbol I, Division 2.3): This material is poisonous by inhalation (see § 171.8 of this subchapter) in Hazard Zone D (see § 173.116(a) of this subchapter), and must be described as an inhalation hazard under the provisions of this subchapter.
• 379: When offered for transport by highway, rail, or cargo vessel, anhydrous ammonia adsorbed or absorbed on a solid contained in ammonia dispensing systems or receptacles intended to form part of such systems is not subject to the requirements of this subchapter if the following conditions in this provision are met. In addition to meeting the conditions in this provision, transport on cargo aircraft only may be authorized with prior approval of the Associate Administrator.
• N87 (symbol I, Division 2.3): The use of copper valves on UN pressure receptacles is prohibited.
• 13 (symbol D, Division 2.2): The words "Inhalation Hazard" shall be entered on each shipping paper in association with the shipping description, shall be marked on each non-bulk package in association with the proper shipping name and identification number, and shall be marked on two opposing sides of each bulk package. Size of marking on bulk package must conform to § 172.302(b) of this subchapter. The requirements of §§ 172.203(m) and 172.505 of this subchapter do not apply.

T50 is a portable tank instruction or provision, defined in 172.102(c)(7) and (c)(8). They are on the row but are not reproduced on this page.

What else to know about this entry

The two rows share the same packaging and stowage columns: 8A None, 8B 304, 8C 314 and 315, and stowage D with other provisions 40, 52 and 57. That means the packaging sections to read are 173.304 for non-bulk and 173.314 and 173.315 for bulk, and none of those sections is reproduced here. Column 8A "None" means the table gives no section number for exceptions.

Column 10B 52 reads "Stow separated from acids" in the 176.84 table, 57 reads "separated from chlorine", and 40 reads "clear of living quarters". Those are vessel stowage codes, so they matter for water shipments, not for a truck load. Special provision 379 separately says anhydrous ammonia adsorbed or absorbed on a solid in ammonia dispensing systems is not subject to the subchapter when listed conditions are met.

The two rows land on different placard tables. A Division 2.3 gas is on Table 1 of 172.504(e), POISON GAS, with no weight threshold. A Division 2.2 gas is on Table 2, NON-FLAMMABLE GAS, with the 1,001 pound exception. Which row a shipment is described under is a classification and shipping paper decision for a trained person; this page shows what each row triggers.

Air quantity limits and a worked example

Columns 9A and 9B give the largest net quantity allowed in one package: column 9A for passenger-carrying aircraft or passenger-carrying rail car, column 9B for cargo aircraft only. 172.101(j) says "Forbidden" means the material may not be offered for transportation or transported in the applicable mode, and that the limit is net unless stated otherwise. For UN1005 the symbol I, Division 2.3 row shows Forbidden in column 9A and Forbidden in column 9B.

Both rows are Forbidden in column 9A and in column 9B, so the calculator returns Forbidden for any quantity you enter, on either row. The calculator above applies the same comparison to the quantity you type.

Highway placard check

Division 2.3 is on Table 1 of 172.504(e) as POISON GAS. 172.504(a) says each bulk packaging, freight container, unit load device, transport vehicle or rail car containing any quantity of a hazardous material must be placarded as specified in tables 1 and 2, so Table 1 materials have no weight threshold. Division 2.2 is on Table 2 of 172.504(e) as NON-FLAMMABLE GAS.

For Table 2 materials moved by highway or rail, 172.504(c) says placards are not required on a transport vehicle or freight container that contains less than 454 kg (1,001 pounds) aggregate gross weight of hazardous materials covered by Table 2, except for bulk packagings and hazardous materials subject to 172.505. In the calculator, 1,000 pounds of non-bulk Table 2 material returns "not required" and 1,001 pounds returns "required", and any bulk packaging returns "required". The weight is the aggregate gross weight of all Table 2 materials on the vehicle, not just this one UN number.

The D row is Division 2.2 and so follows Table 2 (NON-FLAMMABLE GAS) while the I row is Division 2.3 and follows Table 1 (POISON GAS). Special provision 13, which sits on the D row, also says the requirements of 172.203(m) and 172.505 do not apply.

Vessel stowage and the ERG guide

Column 10A gives category D (the material must be stowed "on deck only" on a cargo vessel or on a passenger vessel carrying a limited number of passengers, but it is prohibited on a passenger vessel above that number). Column 10B lists 40, 52, 57. Code 40 in 176.84: Stow "clear of living quarters". Code 52 in 176.84: Stow "separated from" acids. Code 57 in 176.84: Stow "separated from" chlorine. These apply to shipments by vessel and have no effect on a truck-only move.

The Emergency Response Guidebook 2024 numerical index lists UN1005 under Guide 125, titled "Gases - Toxic and/or Corrosive". 172.101 itself does not list ERG guide numbers; the guide number comes from the PHMSA guidebook. The guide is for first responders during the initial phase of an incident and is not a shipping-paper or compliance document.

What this page does not do

It reproduces the table rows and the regulation text it points to, and applies the air-limit and 1,001 pound placard comparisons to numbers you enter. It does not classify a product, pick a packing group, decide which table row applies to your shipment, or replace the packaging sections the row points to (the 173 sections in columns 8A to 8C), the marking, labelling and shipping paper rules in part 172, or hazmat training. Hazardous materials employees must be trained; that decision and the shipping description belong to a trained person. The eCFR header for 172.101 links an amendment published at 91 FR 49310 (August 4, 2026); confirm that the version you rely on includes the latest changes. In an emergency call 911 and the emergency response telephone number on the shipping paper.

Sources

Sources opened and read November 2, 2026. Regulation text was read from the eCFR API, which publishes the current Code of Federal Regulations.

• 49 CFR 172.101, Hazardous Materials Table (eCFR text current through October 29, 2026; read November 2, 2026)
• 49 CFR 172.102, Special provisions (read November 2, 2026)
• 49 CFR 172.504, General placarding requirements (read November 2, 2026)
• 49 CFR 173.115, hazard class definitions (read November 2, 2026)
• 49 CFR 176.84, Other requirements for stowage, cargo handling, and segregation (read November 2, 2026)
• PHMSA: Emergency Response Guidebook 2024 English PDF, numerical index (read via the Internet Archive capture of October 31, 2026; read November 2, 2026)