Phosphorus trioxide

Phosphorus trioxide is the chemical compound with the molecular formula P4O6. Although the molecular formula suggests the name tetraphosphorus hexaoxide, the name phosphorus trioxide preceded the knowledge of the compound's molecular structure, and its usage continues today. This colorless solid is structurally related to adamantane. It is formally the anhydride of phosphorous acid, H3PO3, but cannot be obtained by the dehydration of the acid. Wikipedia

Emergency Response Guide No. 157

Data from the Hazardous Materials Table

Source: 49 CFR §172 (2018/07)

(3) Hazard Class

8
Corrosive liquids

(4) Identification number

UN 2578

(5) Packing Group

III

(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
IP3	Flexible IBCs must be sift-proof and water- resistant or must be fitted with a sift- proof and water-resistant liner. Browse special provision IP3
T1	see 49 CFR §172.102
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	213	see 49 CFR §173.213
(8C) Bulk	240	see 49 CFR §173.240

(9) Quantity Limits

(9A) Passenger aircraft/rail	25 kg
(9B) Cargo aircraft only	100 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

12	Keep as cool as reasonably practicable.
25	Protected from sources of heat

Source: 49 CFR §176.84

Segregation Chart for Load, Transport, Storage

In this table a statement is contained for each hazard class whether the loading, transport or storage with other hazard classes is allowed, is not permitted or is restricted. The table is based on U.S.-Code 49 CFR §177.848.

Note: In this segregation and separation chart are HazMat of hazard class 8 considered depending if there are liquid. Currently HazMat Tool is not able to to check if a HazMat is liquid or not. Therefore it is assumed as liquid. See 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

	May not be loaded, transported, or stored together in the same transport vehicle or storage facility.
	Load, transport, storage together is not restricted.
	Load, transport, storage together is allowed under restrictions.

Substances with similar name

UN-Number	Name	Hazard Class
	Di-2-ethylhexyl phosphoric acid, see Diisooctyl acid phosphate
UN 2751	Diethylthiophosphoryl chloride	8
UN 1768	Difluorophosphoric acid, anhydrous	8
UN 2267	Dimethyl thiophosphoryl chloride	6.1
NA 2927	Ethyl phosphorodichloridate	6.1
UN 1776	Fluorophosphoric acid anhydrous	8
UN 1782	Hexafluorophosphoric acid	8
UN 3278	Organophosphorus compound, liquid, toxic, n.o.s	6.1
UN 3464	Organophosphorus compound, solid, toxic, n.o.s	6.1
UN 3279	Organophosphorus compound, toxic, flammable, n.o.s.	6.1
UN 3018	Organophosphorus pesticides, liquid, toxic	6.1
UN 2783	Organophosphorus pesticides, solid, toxic	6.1
UN 2798	Phenyl phosphorus dichloride	8
UN 3453	Phosphoric acid, solid	8
UN 1805	Phosphoric acid solution	8
UN 2834	Phosphorous acid	8
UN 1810	Phosphorous oxychloride	6.1
	Phosphorus (white or red) and a chlorate, mixtures of	Forbidden
	Phosphorus bromide, see Phosphorus tribromide
UN 1339	Phosphorus heptasulfide, free from yellow or white phosphorus	4.1
UN 1939	Phosphorus oxybromide	8
UN 2576	Phosphorus oxybromide, molten	8
UN 1807	Phosphorus pentoxide	8
UN 2578	Phosphorus trioxide	8
UN 1343	Phosphorus trisulfide, free from yellow or white phosphorus	4.1