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Tetraethyl silicate

HMT 15 June 2026

UN / ID: UN 1292
Hazard class: 3
Packing group: III
ERG guide: ERG 129
Special provisions: SP B1, SP IB3, SP T2, SP TP1
Source: 49 CFR §172 (15 June 2026)

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Tetraethyl silicate

Tetraethyl orthosilicate, formally named tetraethoxysilane (TEOS) or ethyl silicate is an organic compound with the formula Si(OCH2CH3)4. TEOS is a colorless liquid. It degrades in water. TEOS is the ethyl ester of orthosilicic acid, Si(OH)4 Wikipedia

Substance Data

Source: PubChem (HSDB, 21.10.2026)

CAS-Number

78-10-4

Flash Point

52 ° C

Boiling Point

168.8 ° C

Emergency Response Guide No. 129

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

3
Flammable liquids

(4) Identification number

UN 1292

(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.

If the material has a flash point at or above 38 °C (100 °F) and below 93 °C (200 °F), then the bulk packaging requirements of § 173.241 of this subchapter are applicable. If the material has a flash point of less than 38 °C (100 °F), then the bulk packaging requirements of § 173.242 of this subchapter are applicable.

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IB3

_{Authorized IBCs:} Metal (31A, 31B and 31N); Rigid plastics (31H1 and 31H2); Composite (31HZ1 and 31HA2, 31HB2, 31HN2, 31HD2 and 31HH2).
_{Additional Requirement:} Only liquids with a vapor pressure less than or equal to 110 kPa at 50 °C (1.1 bar at 122 °F), or 130 kPa at 55 °C (1.3 bar at 131 °F) are authorized, except for UN2672 (also see special provision IP8 in Table 2 for UN2672).

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Minimum test pressure (bar)	1.5
Minimum shell thickness	§ 178.274(d)(2)
Pressure-relief requirements	Normal
Bottom opening requirements	§ 178.275(d)(3)

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TP1

The maximum degree of filling must not exceed the degree of filling determined by the following:
TP1

Where:
t_r is the maximum mean bulk temperature during transport, and t_f is the temperature in degrees celsius of the liquid during filling.

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(8) Packing Authorizations (§173.***)

(8A) Exceptions	150	see 49 CFR §173.150
(8B) Non-bulk	203	see 49 CFR §173.203
(8C) Bulk	242	see 49 CFR §173.242

(9) Quantity Limits

(9A) Passenger aircraft/rail	60 L
(9B) Cargo aircraft only	220 L

(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.

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
	Tetraethylammonium perchlorate (dry)	Forbidden
UN 1704	Tetraethyl dithiopyrophosphate	6.1
UN 2320	Tetraethylenepentamine	8