UN1993 flammable liquid n.o.s. decoder.

The UN1993 row in the Hazardous Materials Table

The table below is 49 CFR 172.101 as published in the eCFR, current through October 29, 2026, for UN1993. Columns are: class (3), packing group (5), label codes (6), special provisions (7), packaging exceptions (8A), non-bulk packaging (8B), bulk packaging (8C), quantity limits for passenger aircraft or railcar (9A) and cargo aircraft only (9B), and vessel stowage (10A and 10B). UN1993 has 3 rows, so each one is listed.

Reading the packaging columns

Columns 8A to 8C do not hold rules themselves; they point to sections of part 173. For this entry they point to:

• 173.150: Exceptions for Class 3 (flammable and combustible liquids).
• 173.201: Non-bulk packagings for liquid hazardous materials in Packing Group I.
• 173.243: Bulk packaging for certain high hazard liquids and dual hazard materials which pose a moderate hazard.
• 173.202: Non-bulk packagings for liquid hazardous materials in Packing Group II.
• 173.242: Bulk packagings for certain medium hazard liquids and solids, including solids with dual hazards.
• 173.203: Non-bulk packagings for liquid hazardous materials in Packing Group III.

Exceptions in column 8A apply only if that section is referenced for the specific material in the table, so a limited quantity route that exists for one UN number is not automatically open to another.

Special provisions on this entry

The letter prefixes on special provisions tell you where each applies (172.102(c)): a code of only numbers is multi-modal; "A" applies only to transportation by aircraft; "B" only to bulk packaging; "IB" and "IP" only to IBCs; "N" only to non-bulk packaging; "T" and "TP" only to UN portable tanks.

• T11: a portable tank instruction. It set the minimum test pressure, shell thickness, bottom opening and pressure relief requirements for UN portable tanks.
• TP1: The maximum degree of filling of a portable tank must not exceed the figure from the formula given in the provision.
• TP27: A portable tank with a minimum test pressure of 4 bar (400 kPa) may be used if the calculated test pressure is 4 bar or less.
• IB2: Authorized IBCs: metal (31A, 31B, 31N), rigid plastic (31H1, 31H2) and composite (31HZ1).
• T7: a portable tank instruction. It set the minimum test pressure, shell thickness, bottom opening and pressure relief requirements for UN portable tanks.
• TP8: A portable tank with a minimum test pressure of 1.5 bar (150 kPa) may be used when the flash point of the material is greater than 0 degrees C (32 degrees F).
• TP28: A portable tank with a minimum test pressure of 2.65 bar (265 kPa) may be used if the calculated test pressure is 2.65 bar or less.
• B1: If the flash point is at or above 38 degrees C (100 degrees F) and below 93 degrees C (200 degrees F), the bulk packaging requirements of 173.241 apply; below 38 degrees C (100 degrees F), 173.242 applies.
• B52: Non-reclosing pressure relief devices are authorized on DOT 57 portable tanks.
• IB3: Authorized IBCs: metal (31A, 31B, 31N), rigid plastic (31H1, 31H2) and composite (31HZ1 and 31HA2, 31HB2, 31HN2, 31HD2, 31HH2).
• T4: a portable tank instruction. It set the minimum test pressure, shell thickness, bottom opening and pressure relief requirements for UN portable tanks.
• TP29: A portable tank with a minimum test pressure of 1.5 bar (150 kPa) may be used if the calculated test pressure is 1.5 bar or less.

What n.o.s. means and when you may use it

N.O.S. stands for "not otherwise specified". The proper shipping name rules in the column 2 description of 172.101 say that if a material is not named in the table, you pick the generic or n.o.s. description that matches its hazard class, packing group and any subsidiary hazard, choosing the name that most appropriately describes the material. For a flammable alcohol not listed by name, the example in the rule is "Alcohol, n.o.s." rather than "Flammable liquid, n.o.s." The table has more specific n.o.s. entries, such as flammable liquids that are also toxic or corrosive, so UN1993 is the last choice rather than the first.

The G symbol: technical names

Column 1 of the UN1993 row shows the letter G. The symbol G identifies proper shipping names for which one or more technical names of the hazardous material must be entered in parentheses, in association with the basic description (the table points to 172.203(k)). A UN1993 shipment therefore reads like "UN1993, Flammable liquids, n.o.s. (toluene, xylene), 3, II" rather than the generic name alone. The ERG 2024 index also lists a number of products against UN1993 and Guide 128, including Combustible liquid n.o.s., Diesel fuel and Fuel oil.

Three groups, three packaging routes

The rows differ in packaging: Group I uses 173.201 and bulk 173.243 with T11 and TP27; Group II uses 173.202 and bulk 173.242 with IB2, T7, TP1, TP8 and TP28; Group III uses 173.203 and bulk 173.242 with B1, B52, IB3, T4, TP1 and TP29. The group comes from the flash point and initial boiling point under 173.121(a), which the Class 3 checker on this site applies. Column 10A stowage is E for Group I, B for Group II and A for Group III.

ERG 2024 Guide 128: Flammable Liquids (Water-Immiscible)

The ERG 2024 numerical index lists UN1993 against Guide 128. The guide appears on pages 185 to 186 of the 2024 guidebook. The guidebook is meant for first responders during the initial phase of an incident, and it says to call 911 and then the emergency response telephone number on the shipping paper.

• Fire or explosion: "HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames." Vapors may form explosive mixtures with air, may travel to a source of ignition and flash back, and most are heavier than air. Many of these liquids float on water, and the guide notes the substance may be transported hot.
• Health: inhalation or contact may irritate or burn skin and eyes; fire may produce irritating, corrosive or toxic gases; vapors may cause dizziness or asphyxiation in confined areas.
• Evacuation: isolate a spill or leak area for at least 50 meters (150 feet) in all directions; for a large spill consider initial downwind evacuation of at least 300 meters (1000 feet); for a tank, rail tank car or highway tank in a fire, isolate for 800 meters (1/2 mile).
• Fire response: small fire, dry chemical, CO2, water spray or regular foam (alcohol-resistant foam if regular foam is ineffective or unavailable); large fire, water spray, fog or regular foam. For mixtures containing alcohol or a polar solvent, alcohol-resistant foam may be more effective.

The guide is a starting point until the material is identified. Read the full guide in the current ERG, and use the shipping paper emergency number for product-specific advice.

Placards, quantity and vessel stowage

3 is a Table 2 category in 172.504(e), so the placard is FLAMMABLE. On a highway vehicle with less than 454 kg (1,001 pounds) aggregate gross weight of Table 2 materials in non-bulk packages, no placard is required, but bulk packagings and materials subject to 172.505 are not eligible for that exception (172.504(c)).

Vessel stowage is the category in column 10A (E, B, A), which the table sets for this entry, plus the column 10B codes. Column 10B is blank for this entry. Hazmat shipped as a limited quantity is allocated stowage category A and is not subject to the column 10B stowage codes (176.63(a)).

Worked example

A lab ships 2 L of an unlisted solvent blend with a closed-cup flash point of 10 degrees C and an initial boiling point of 80 degrees C. Flash point below 23 degrees C and boiling point above 35 degrees C puts it in Packing Group II under 173.121, so the row to use is Group II, which allows 5 L per package on passenger aircraft. The shipping name carries the technical name because of the G symbol. If the blend also meets a toxic or corrosive definition, a more specific n.o.s. entry is the right choice.

Limits

This page reads the 172.101 table, the 172.102 special provisions, 172.504 and the section titles named above, plus ERG 2024. It does not classify your material, choose a proper shipping name, or build shipping papers, marks, labels or training requirements. The checker compares your net quantity to the printed column 9A and 9B limits and applies the 1,001 pound rule to the class on the row; it does not model subsidiary hazard placards (172.505), mixed loads, state rules or carrier restrictions. Special provisions are shown in summary; read the full text in 172.102 before relying on one. Hazmat shipping needs trained hazmat employees (49 CFR part 172, subpart H).

Sources

Sources opened and read November 2, 2026.

• eCFR: 49 CFR 172.101, Hazardous Materials Table (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 172.102, special provisions (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 172.504, general placarding requirements (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.150, Exceptions for Class 3 (flammable and combustible liquids) (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.201, Non-bulk packagings for liquid hazardous materials in Packing Group I (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.243, Bulk packaging for certain high hazard liquids and dual hazard materials which pose a moderate hazard (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.202, Non-bulk packagings for liquid hazardous materials in Packing Group II (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.242, Bulk packagings for certain medium hazard liquids and solids, including solids with dual hazards (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.203, Non-bulk packagings for liquid hazardous materials in Packing Group III (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 176.84, other requirements for stowage, cargo handling and segregation (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 176.63, stowage locations (current through October 29, 2026) (read November 2, 2026)
• PHMSA: Emergency Response Guidebook (ERG) landing page (read November 2, 2026)
• PHMSA: ERG 2024 PDF, numerical index and guide pages (the phmsa.dot.gov host refused automated requests; the Internet Archive copy of this file was read) (read November 2, 2026)