HazMat Tool — substance information

Butyl nitrites

HMT 15 June 2026
Reference only — HMT snapshot for inspection and audit support; not a shipping paper, placard mandate, or CVI record. Use Print / PDF below for field notes.
UN / ID
UN 2351
Hazard class
3
Packing group
I (multiple — see tabs)
ERG guide
ERG 129
Special provisions
SP T11, SP TP1, SP TP8, SP TP27
Source
49 CFR §172 (15 June 2026)

Spot an error in this entry?

Butyl nitrites


In organic chemistry, butyl is a four-carbon alkyl radical or substituent group with general chemical formula −C4H9, derived from either of the two isomers (n-butane and isobutane) of butane. The isomer n-butane can connect in two ways, giving rise to two "-butyl" groups: If it connects at one of the two terminal carbon atoms, it is normal butyl or n-butyl: −CH2−CH2−CH2−CH3 (preferred IUPAC name: butyl) If it connects at one of the non-terminal (internal) carbon atoms, it is secondary butyl or sec-butyl: −CH(CH3)−CH2−CH3 (preferred IUPAC name: butan-2-yl) The second isomer of butane, isobutane, can also connect in two ways, giving rise to two additional groups: If it connects at one of the three terminal carbons, it is isobutyl: −CH2−CH(CH3)2 (preferred IUPAC name: 2-methylpropyl) If it connects at the central carbon, it is tertiary butyl, tert-butyl or t-butyl: −C(CH3)3 (preferred IUPAC name: tert-butyl) Wikipedia

Emergency Response Guide No. 129

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard Class

3
Flammable liquids

(4) Identification number Help

UN 2351

(5) Packing Group Help

I

(6) Labels Help

Flammable liquids (3)

(7) Special Provisions (§172.102) Help

×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.
T11
TP1
TP8
TP27

(8) Packing Authorizations (§173.***) Help

(8A) Exceptions150see 49 CFR §173.150
(8B) Non-bulk201see 49 CFR §173.201
(8C) Bulk243see 49 CFR §173.243

(9) Quantity Limits Help

(9A) Passenger aircraft/rail1 L
(9B) Cargo aircraft only30 L

(10) Vessel stowage Help

(10A) Location
(10B) Other

(3) Hazard Class

3
Flammable liquids

(4) Identification number Help

UN 2351

(5) Packing Group Help

II

(6) Labels Help

Flammable liquids (3)

(7) Special Provisions (§172.102) Help

×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.
IB2
T4
TP1

(8) Packing Authorizations (§173.***) Help

(8A) Exceptions150see 49 CFR §173.150
(8B) Non-bulk202see 49 CFR §173.202
(8C) Bulk242see 49 CFR §173.242

(9) Quantity Limits Help

(9A) Passenger aircraft/rail5 L
(9B) Cargo aircraft only60 L

(10) Vessel stowage Help

(10A) Location
(10B) Other

(3) Hazard Class

3
Flammable liquids

(4) Identification number Help

UN 2351

(5) Packing Group Help

III

(6) Labels Help

Flammable liquids (3)

(7) Special Provisions (§172.102) Help

×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.
B1
IB3
T2
TP1

(8) Packing Authorizations (§173.***) Help

(8A) Exceptions150see 49 CFR §173.150
(8B) Non-bulk203see 49 CFR §173.203
(8C) Bulk242see 49 CFR §173.242

(9) Quantity Limits Help

(9A) Passenger aircraft/rail60 L
(9B) Cargo aircraft only220 L

(10) Vessel stowage Help

(10A) Location
(10B) Other

Packing group comparison

Multiple packing groups apply to this entry. See assignment criteria in 49 CFR §173 Subpart D. Details are in the tabs above; differences are highlighted.

PG I PG II PG III
1
2Butyl nitritesButyl nitritesButyl nitrites
3333
4UN 2351UN 2351UN 2351
5IIIIII
6333
7T11, TP1, TP8, TP27IB2, T4, TP1B1, IB3, T2, TP1
8A150150150
8B201202203
8C243242242
9A1 L5 L60 L
9B30 L60 L220 L
10AEBA
10B404040

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.

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

Similar substances

UN / IDProper shipping nameHazard class
UN 3219Nitrites, inorganic, aqueous solution, n.o.s5.1
UN 2627Nitrites, inorganic, n.o.s.5.1