Transport reference
UN 1064 — Methyl mercaptan
Table A of ADR 2025 and the 49 CFR 172.101 Hazardous Materials Table for this number, kept side by side and never merged, plus the CLP label elements of the substances that ship under it.
The two tables are never merged. The same UN number can carry a different packing group, a different proper shipping name and entirely different special provisions in each system. Every value below sits under the name of the jurisdiction it comes from.
01 · Two jurisdictions
UN 1064 in ADR 2025 and in 49 CFR 172.101
The two systems differ for this number on 1 of 5 fields. Special provisions are deliberately absent from this comparison: identical code numbers mean different things in the two systems.
| Field | ADR 2025 Table A, Chapter 3.2 | 49 CFR 172.101 eCFR 2026-08-03 |
|---|---|---|
| Proper shipping name | METHYL MERCAPTAN | Methyl mercaptan |
| Class or division | 2 | 2.3 |
| Packing group | — | — |
| Label codes | 2.3, 2.1 | 2.3, 2.1 |
| Rows in the table | 1 | 1 |
Sources: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE) · 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03
02 · ADR 2025
UN 1064 in Table A of ADR 2025
One row in Table A of Chapter 3.2. Every value below comes from that row.
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels | Transport category | Hazard ID |
|---|---|---|---|---|---|---|
| METHYL MERCAPTAN | 2 | 2TF | — | 2.3, 2.1 | 1 | 263 |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 2 is “Gases” (ADR 2.1.1.1).
Transport category and the 1 000-point exemption
Column (15) of Table A decides whether a load stays under the exemption of ADR 1.1.3.6. Quantities of different categories are added with the multipliers below, and the sum must not exceed 1 000.
| Category | Max total quantity per transport unit | Multiplier in 1.1.3.6.4 | What it means |
|---|---|---|---|
| 1 | 20 | × 50 | Packing group I and the listed classes — the exemption runs out after 20 kg or litres per transport unit. |
Source: ADR 2025, 1.1.3.6.3 and 1.1.3.6.4 · ECE/TRANS/352 Vol. I (UNECE).
Carriage provisions — CV codes
| CV10 | Cylinders must be laid parallel or at right angles to the axis and secured. |
| CV36 | Preferably loaded in open or ventilated vehicles; if closed, warning about ventilation before entry. · relevant to segregation on the vehicle |
| CV9 | Packages must not be thrown or subjected to impact. |
Source: ADR 2025, 7.5.11 · ECE/TRANS/352 Vol. II (UNECE)
Not imported and therefore not shown for this number: limited quantities (column 7a), excepted quantities (7b), packing instructions (8), tank codes (10–13) and the tunnel restriction code (15). An empty section is more honest than borrowed text.
03 · United States
UN 1064 in the 49 CFR 172.101 Hazardous Materials Table
One row in the Hazardous Materials Table.
| Symbols (1) | Proper shipping name (2) | Class (3) | PG (5) | Labels (6) | Packaging (8) | Quantity limits (9) | Vessel stowage (10) |
|---|---|---|---|---|---|---|---|
| — | Methyl mercaptan | 2.3 | — | 2.3, 2.1 | §173.None · §173.304 · §173.314, 315 | Forbidden passenger Forbidden cargo | D · 40 |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 2.3 is “Poisonous gas” (49 CFR 173.2). Packaging cells are section references into 49 CFR part 173: exceptions, non-bulk, bulk. Handling codes in column 10B are defined in 49 CFR 176.84, which is not part of our import — the numbers are shown as printed in the table.
Vessel stowage categories on this entry
| D | Must be stowed “on deck only” on a cargo vessel or on a passenger vessel within the 25-passenger limit; prohibited on a passenger vessel above that limit. |
Source: 49 CFR 172.101(k) · eCFR, revision 2026-08-03
Special provisions — 49 CFR 172.102
Codes from column (7) of the Hazardous Materials Table, with the text of § 172.102. These are United States provisions only and have nothing to do with the ADR codes above, even where the number is identical.
| 3 | This material is poisonous by inhalation (see § 171.8 of this subchapter) in Hazard Zone C (see § 173.116(a) of this subchapter), and must be described as an inhalation hazard under the provisions of this subchapter. |
| B14 | Each bulk packaging, except a tank car or a multi-unit-tank car tank, must be insulated with an insulating material so that the overall thermal conductance at 15.5 °C (60 °F) is no more than 1.5333 kilojoules per hour per square meter per degree Celsius (0.075 Btu per hour per square foot per degree Fahrenheit) temperature differential. Insulating materials must not promote corrosion to steel when wet. |
| B7 | Safety relief devices are not authorized on multi-unit tank car tanks. Openings for safety relief devices on multi-unit tank car tanks shall be plugged or blank flanged. |
| B9 | Bottom outlets are not authorized. |
| N89 | When steel UN pressure receptacles are used, only those bearing the “H” mark are authorized. |
| T50 | When portable tank instruction T50 is indicated in Column (7) of the § 172.101 Hazardous Materials Table, the applicable liquefied compressed gas and chemical under pressure descriptions are authorized to be transported in portable tanks in accordance with the requirements of § 173.313 of this subchapter. |
Source: 49 CFR 172.102 special provisions · eCFR, revision 2026-08-03
04 · Orange plate
The orange-coloured plate for UN 1064
The upper half of the plate carries the hazard identification number, the lower half the UN number. Dimensions follow ADR 5.3.2.2.1: 400 × 300 mm, black border and dividing line 15 mm, figures 100 mm high.
263 — toxic gas, flammable.
| 2 | Emission of gas due to pressure or to chemical reaction |
| 6 | Toxicity or risk of infection |
| 3 | Flammability of liquids (vapours) and gases or self-heating liquid |
Source: ADR 2025, 5.3.2.3 · ECE/TRANS/352 Vol. II (UNECE). The tunnel restriction code of column (15) is a different value and is not part of our import.
05 · Substances
Substances shipped under UN 1064
Linked by CAS number, never by name: a name match once produced “acetone cyanohydrin” for acetone, and a wrong link here would be a wrong classification. Each entry opens its own reference page with the CLP classification and label elements.
06 · The label side
What UN 1064 looks like on a workplace label
The tables above are the transport classification. This is the other half of the same material: the CLP label elements of the substances linked to this number — what actually goes on the drum once it has been delivered. Transport marks and supply labels answer different regulations and do not replace one another.
Hazard statements on the substances under UN 1064
| H220 | Extremely flammable gas. |
| H331 | Toxic if inhaled. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
Source: harmonised classification, EU CLP Annex VI. Transport classification and supply classification are decided under different rules and do not have to agree.
07 · FAQ
UN 1064 — frequently asked questions
What is UN 1064?
UN 1064 is the United Nations number for Methyl mercaptan. Under ADR 2025 it is assigned to class 2 (gases), classification code 2TF.
Is UN 1064 classified the same way in the United States and in Europe?
No. For UN 1064 the two tables differ on class or division. Each panel on this page shows its own source; values from one system must not be carried over into the other.
What is the hazard identification number for UN 1064?
The orange-coloured plate for UN 1064 carries the hazard identification number 263 above the UN number. Under ADR 5.3.2.3.2 that number means: toxic gas, flammable.
What is the transport category of UN 1064?
Column (15) of Table A puts UN 1064 in transport category 1. Under ADR 1.1.3.6.3 the maximum total quantity per transport unit for that category is 20.
Which substances ship under UN 1064?
We hold 1 substance linked to UN 1064 by CAS number. Each one has its own reference page with the CLP classification, GHS pictograms and hazard statements that apply on the label — the workplace side of the same material.
Need the plate, the labels or the placards printed?
The orange plate above is a physical article, and so are the class labels in column (5). Our sister site GHSLabels.com covers printing and suppliers. For the workplace label of the same material, use the GHS label constructor, and browse other numbers in the UN number reference.
Reference aid only. Values are reproduced from ADR 2025 and the 49 CFR 172.101 table as published; the consignor remains responsible for the classification of a specific consignment. Always verify against the current published regulation and the supplier's safety data sheet.