DOT transport classification

Ammonia solution (ammonium hydroxide): UN number by concentration

Under 49 CFR 172.101, ammonia solution (ammonium hydroxide) ≤10% is not regulated; >10% and ≤35% ships as UN2672 (class 8, packing group III); >35% ships as UN2073 (class 2.2).

CAS 1336-21-6 · Source: 49 CFR 172.101 Hazardous Materials Table

Classification by concentration

Ammonia solution (ammonium hydroxide) — 49 CFR 172.101. Percentages are by mass (w/w).
Concentration	Ships as	Class	Packing group	What we stock in this band
≤10%	Not regulated	—	—	Ammonium Hydroxide 5% ACS Grade Ammonium Hydroxide 5% Technical Grade Gleam Guru - Ammonia Cleaning Solution Technical Grade
>10% and ≤35%	UN2672	8	III	Ammonium Hydroxide 10% ACS Grade^† Ammonium Hydroxide 10% Technical Grade^† Ammonium Hydroxide 15% ACS Grade Ammonium Hydroxide 15% Technical Grade Ammonium Hydroxide 20% ACS Grade Ammonium Hydroxide 20% Technical Grade Ammonium Hydroxide 29% ACS Grade Ammonium Hydroxide 29% Technical Grade
>35%	UN2073	2.2	—	Nothing in this band

≤10%: Generally not regulated at this strength.
>10% and ≤35%: Relative density 0.880-0.957.
>35%: Density below 0.880 — a compressed-gas entry, not a corrosive liquid. Anhydrous ammonia is UN1005 (Class 2.3, toxic gas).

How to read this

Percentages are by mass. 49 CFR 172.101 thresholds are w/w, but product labels often state volume (v/v). Near a cutoff the two can fall on opposite sides, so confirm the basis before classifying a shipment.
† This product's verified classification places it in this band even though its nominal (volume) percentage would suggest the neighbouring one — the by-mass figure is what governs.
Products listed are verified individually. A product appears in a band only when its own reviewed classification matches it. Where a product's classification is still under review, we leave it out rather than infer it from the table.
This page is a reference, not a shipping paper. Classification for an actual shipment depends on packaging, quantity and mode; consult the current eCFR entry and the product's safety data sheet.

Source

49 CFR 172.101 Hazardous Materials Table. Reference text: “This entry = aqueous ammonia >10% to <=35% (density 0.880-0.957). Class 8 PG III, no subsidiary. >35% ammonia (density <0.880) => UN2073 (Class 2.2) or, if anhydrous, UN1005 (Class 2.3, toxic gas). <=10% ammonia is generally not regulated.”

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