HazMat Tool — substance information Reference only — not a shipping paper, placard mandate, or CVI record.

Potassium hydrogendifluoride solid

HMT 15 June 2026

UN / ID: UN 1811
Hazard class: 8
Packing group: II
ERG guide: ERG 154
Special provisions: SP IB8, SP IP2, SP IP4, SP N3, SP N34, SP T3, SP TP33
Source: 49 CFR §172 (15 June 2026)

On this page

Potassium hydrogendifluoride solid

Potassium is a chemical element; it has symbol K (from Neo-Latin kalium) and atomic number 19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives Wikipedia

Emergency Response Guide No. 154

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

8
Corrosive liquids

(4) Identification number

UN 1811

(5) Packing Group

(6) Labels

(7) Special Provisions (§172.102)

×Note:
Special provisions may be very complex. The extracts are taken from 49 CFR §172.102. Please be careful with the information, as necessary, additional conditions may be applied that are not written here. Please check the original source and report bugs.

IB8

_{Authorized IBCs:} Metal (11A, 11B, 11N, 21A, 21B, 21N, 31A, 31B and 31N); Rigid plastics (11H1, 11H2, 21H1, 21H2, 31H1 and 31H2 ); Composite (11HZ1, 11HZ2, 21HZ1, 21HZ2 and 31HZ1); Fiberboard (11G); Wooden (11C, 11D and 11F); Flexible (13H1, 13H2, 13H3, 13H4, 13H5, 13L1, 13L2, 13L3, 13L4, 13M1 or 13M2).

Browse special provision IB8

IP2

When IBCs other than metal or rigid plastics IBCs are used, they must be offered for transportation in a closed freight container or a closed transport vehicle.

Browse special provision IP2

IP4

Flexible, fiberboard or wooden IBCs must be sift-proof and water-resistant or be fitted with a sift-proof and water-resistant liner.

Browse special provision IP4

Glass inner packagings are permitted in combination or composite packagings only if the hazardous material is free from hydrofluoric acid.

Browse special provision N3

N34

Aluminum construction materials are not authorized for any part of a packaging which is normally in contact with the hazardous material.

Browse special provision N34

Minimum test pressure (bar)	2.65
Minimum shell thickness	§ 178.274(d)(2)
Pressure-relief requirements	Normal
Bottom opening requirements	§ 178.275(d)(2)

Browse special provision T3

TP33

The portable tank instruction assigned for this substance applies for granular and powdered solids and for solids which are filled and discharged at temperatures above their melting point which are cooled and transported as a solid mass. Solid substances transported or offered for transport above their melting point are authorized for transportation in portable tanks conforming to the provisions of portable tank instruction T4 for solid substances of packing group III or T7 for solid substances of packing group II, unless a tank with more stringent requirements for minimum shell thickness, maximum allowable working pressure, pressure-relief devices or bottom outlets are assigned in which case the more stringent tank instruction and special provisions shall apply. Filling limits must be in accordance with portable tank special provision TP3. Solids meeting the definition of an elevated temperature material must be transported in accordance with the applicable requirements of this subchapter.

Browse special provision TP33

(8) Packing Authorizations (§173.***)

(8A) Exceptions	154	see 49 CFR §173.154
(8B) Non-bulk	212	see 49 CFR §173.212
(8C) Bulk	240	see 49 CFR §173.240

(9) Quantity Limits

(9A) Passenger aircraft/rail	15 kg
(9B) Cargo aircraft only	50 kg

(10) Vessel stowage

(10A) Location

Stowage category “A” means the material may be stowed “on deck” or “under deck” on a cargo vessel or on a passenger vessel.

Source: 49 CFR §172.101(k)

(10B) Other

25	see 49 CFR §176.84
40	see 49 CFR §176.84
52	see 49 CFR §176.84
53	see 49 CFR §176.84
58	see 49 CFR §176.84

Source: 49 CFR §176.84

Segregation chart for load, transport, and storage

This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.

Hinweis: In der Kompatibilitätstabelle sind Stoffe der Gefahrenklasse 8 nur dann zu berücksichtigen, wenn der Stoff flüssig ist. Derzeit kann HazMat Tool nicht prüfen, ob der Stoff flüssig ist. Dies wird daher hier angenommen. Siehe PHMSA Interpretation #09-0252.

Hazard class	8	7	6.1	5.2	5.1	4.3	4.2	4.1	3	2.3B	2.3A	2.2	2.1	1.6	1.5	1.4	1.3	1.1/1.2
1.1/1.2
1.3
1.4
1.5
1.6
2.1
2.2
2.3A
2.3B
3
4.1
4.2
4.3
5.1
5.2
6.1
7
8

	Must not be loaded, transported, or stored together in the same vehicle or facility.
	May be loaded, transported, or stored together.
	May be loaded, transported, or stored together only with restrictions.

Similar substances

UN / ID	Proper shipping name	Hazard class
UN 1382	Potassium sulfide, anhydrous or Potassium sulfide with less than 30 percent water of crystallization	4.2
UN 1847	Potassium sulfide, hydrated with not less than 30 percent water of crystallization	8
UN 3028	Batteries, dry, containing potassium hydroxide solid, electric storage	8
UN 3421	Potassium hydrogendifluoride solution	8
UN 1487	Potassium nitrate and sodium nitrite mixtures	5.1
UN 1499	Sodium nitrate and potassium nitrate mixtures	5.1
UN 1812	Potassium fluoride, solid	6.1
UN 3403	Potassium, metal alloys, solid	4.3
UN 3422	Potassium fluoride solution	6.1
UN 2509	Potassium hydrogen sulfate	8
UN 1420	Potassium, metal alloys, liquid	4.3
UN 3404	Potassium sodium alloys, solid	4.3
UN 2427	Potassium chlorate, aqueous solution	5.1
	Potassium dichloro isocyanurate or Potassium dichloro-s-triazinetrione, see Dichloroisocyanuric acid, dry or Dichloroisocyanuric acid salts etc
UN 1929	Potassium dithionite or Potassium hydrosulfite	4.2