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Calcium oxide

HMT 15 June 2026

UN / ID: UN 1910
Hazard class: 8
Packing group: III
ERG guide: ERG 157
Special provisions: SP IB8, SP IP3, SP T1, SP TP33
Source: 49 CFR §172 (15 June 2026)

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Calcium oxide

Calcium oxide (formula: CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. The broadly used term lime connotes calcium-containing inorganic compounds, in which carbonates, oxides, and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate. By contrast, quicklime specifically applies to the single compound calcium oxide Wikipedia

Substance Data

Source: PubChem (HSDB, 21.10.2026)

CAS-Number

1305-78-8

Flash Point

—

Boiling Point

2850 ° C

Emergency Response Guide No. 157

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

8
Corrosive liquids

(4) Identification number

UN 1910

(5) Packing Group

III

(6) Labels

(1) Symbols

This entry is signed with "A". The letter "A" denotes a material that is subject to the requirements of this subchapter only when offered or intended for transportation by aircraft, unless the material is a hazardous substance or a hazardous waste. A shipping description entry preceded by an "A" may be used to describe a material for other modes of transportation provided all applicable requirements for the entry are met.

(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	<sub>Authorized IBCs:</sub> 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	<table class="table table-bordered table-condensed ushmr-sp-table"><tr><th>Minimum test pressure (bar)</th><td>1.5</td></tr><tr><th>Minimum shell thickness</th><td>§ 178.274(d)(2)</td></tr><tr><th>Pressure-relief requirements</th><td>Normal</td></tr><tr><th>Bottom opening requirements</th><td>§ 178.275(d)(2)</td></tr></table> Browse special provision T1
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	A 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	—

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 3487	Calcium hypochlorite, hydrated, corrosive or Calcium hypochlorite, hydrated mixture, corrosive with not less than 5.5% but not more than 16% water	5.1
UN 3485	Calcium hypochlorite, dry, corrosive or Calcium hypochlorite mixture, dry, corrosive with more than 39% available chlorine (8.8% available oxygen)	5.1
UN 2880	Calcium hypochlorite, hydrated or Calcium hypochlorite, hydrated mixture, with not less than 5.5% but not more than 16% water	5.1
UN 3486	Calcium hypochlorite mixture, dry, corrosive with more than 10% but not more than 39% available chlorine	5.1
UN 1748	Calcium hypochlorite, dry or Calcium hypochlorite mixture dry with more than 39% available chlorine (8.8% available oxygen)	5.1
UN 2907	Isosorbide dinitrate mixture with not less than 60 percent lactose, mannose, starch or calcium hydrogen phosphate	4.1
UN 2208	Calcium hypochlorite mixture, dry, with more than 10% but not more than 39% available chlorine	5.1
UN 1403	Calcium cyanamide with more than 0.1 percent of calcium carbide	4.3
UN 1574	Calcium arsenate and calcium arsenite, mixtures, solid	6.1
UN 1855	Calcium, pyrophoric or Calcium alloys, pyrophoric	4.2
UN 2429	Calcium chlorate aqueous solution	5.1
UN 1923	Calcium dithionite or Calcium hydrosulfite	4.2
UN 2844	Calcium manganese silicon	4.3
UN 1314	Calcium resinate, fused	4.1