Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

Tetraethyl silicate

Tetraethyl silicate is a colorless liquid with a sharp, ester-like odor.

CAS 78-10-4 C8H20O4Si 208.33 g/mol Warning

01 · Identification

What Tetraethyl silicate is

Tetraethyl silicate is a colorless liquid with a sharp, ester-like odor. Its molecular formula is C8H20O4Si and its molecular weight is 208.33 g/mol. It boils at 169 °C, melts at -82.5 °C.

Under the GHS it carries the signal word Warning. It is classed as flammable agents - 3rd degree.

02 · Identifiers

Tetraethyl silicate identifiers and molecular data

Tetraethyl silicate CAS number and EC number

CAS number78-10-4
EC number201-083-8
Index number (CLP Annex VI)014-005-00-0

Tetraethyl silicate molecular formula and molecular weight

Molecular formulaC8H20O4Si
Molecular weight208.33 g/mol
Chemical class Flammable agents - 3rd degree

Other names for Tetraethyl silicate

  • ethyl silicate

03 · GHS classification

Tetraethyl silicate hazard classification

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Tetraethyl silicate pictograms and signal word

Signal wordWarning

Tetraethyl silicate hazard class and category

GHS hazard classes Tetraethyl silicate falls into
Hazard class Category From code Pictogram
Flammable liquids GHS chapter 2.6 Category 3 H226 GHS02
Acute toxicity - inhalation GHS chapter 3.1 Category 4 H332 GHS07
Serious eye damage/eye irritation GHS chapter 3.3 Category 2A H319 GHS07
Specific target organ toxicity - single exposure GHS chapter 3.8 Category 3 H335 GHS07

Tetraethyl silicate hazard statements (H-codes)

Hazard statements assigned to Tetraethyl silicate
CodeHazard statement
H226 Flammable liquid and vapour.
H332 Harmful if inhaled.
H335 May cause respiratory irritation.
H319 Causes serious eye irritation.

This page lists only the codes assigned to Tetraethyl silicate. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.

Safety Data Sheet

Getting an SDS for Tetraethyl silicate

A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Tetraethyl silicate issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.

04 · Precautionary statements

Tetraethyl silicate precautionary statements

CLP Annex VI assigns 15 precautionary statements to Tetraethyl silicate. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.

Storage

How the container has to be kept between uses.

Reading the notation. is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.

05 · Names in the regulation

Tetraethyl silicate name in 23 EU languages

CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.

Language Name in CLP Annex VI Part 3
Bulgarian български тетраетилов силикат етилов силикат
Spanish español Silicato de tetraetilo silicato de etilo
Czech čeština tetraethoxysilan
Danish dansk tetraethylsilicat ethylsilicat
German Deutsch Tetraethylsilicat EthylsilicatTetraethoxysilan
Estonian eesti tetraetüülsilikaat etüülsilikaat
Greek ελληνικά πυριτικός τετρααιθυλεστέρας πυριτικό αιθύλιo
English English tetraethyl silicate ethyl silicate
French français silicate de tétraéthyle silicate d'éthyle
Croatian hrvatski tetraetil-silikat etil-silikat
Italian italiano silicato di tetraetile etile silicato
Latvian latviešu tetraetilsilikāts etilsilikāts
Lithuanian lietuvių tetraetilsilikatas etilsilikatas
Hungarian magyar tetraetil-szilikát etil-szilikát
Maltese Malti silikat tat-tetraetil silikat tal-etil
Dutch Nederlands tetraëthylsilicaat ethylsilicaat
Polish polski tetraetoksysilan ortokrzemian tetraetylukrzemian etylu
Portuguese português silicato de tetraetilo silicato de etilo
Romanian română silicat de tetraetil silicat de etil
Slovak slovenčina tetraetyl-silikát etyl-silikát
Slovenian slovenščina tetraetil ortosilikat etil silikat
Finnish suomi tetraetyylisilikaatti etyylisilikaatti
Swedish svenska tetraetylsilikat etylsilikat

All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.

06 · Label elements

Tetraethyl silicate GHS label elements

Everything CLP Annex VI fixes for Tetraethyl silicate, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS02 Flame pictogramGHS07 Exclamation mark pictogram

Warning

Tetraethyl silicate

  • Flammable liquid and vapour.
  • Harmful if inhaled.
  • May cause respiratory irritation.
  • Causes serious eye irritation.
  • Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • Keep container tightly closed.
  • Use explosion-proof [electrical/ventilating/lighting/…] equipment.
  • Use only non-sparking tools.
  • Do not breathe dust/fume/gas/mist/vapours/spray.
  • Wash thoroughly after handling.
  • Use only outdoors or in a well-ventilated area.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF INHALED:
  • IF IN EYES:
  • Call a POISON CENTER/doctor/ if you feel unwell.
  • Get medical advice/attention.
  • If eye irritation persists:
  • Remove contact lenses, if present and easy to do. Continue rinsing.
  • Store in a well-ventilated place.

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open Tetraethyl silicate in the GHS label constructor →

07 · Health hazards

Tetraethyl silicate health hazards and exposure limits

Tetraethyl silicate hazard summary

Rats that survived concentrations of 400 ppm for 7 hours/day for 30 days show liver, kidney, and lung damage. [ACGIH] Causes eye irritation at 250 ppm and tearing at 1,200 ppm; [CSH, p. 402] A skin and respiratory tract irritant; Liquid defats the skin and vapor may depress consciousness; [ICSC] In high-dose animal experiments, it acts as a general anesthetic; [ChemIDplus] See Methyl silicate.

Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

Tetraethyl silicate occupational exposure limits

US occupational exposure limits reported for Tetraethyl silicate. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL 100.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
PEL 100 ppm (850 mg/m³) Occupational Safety and Health Administration (OSHA)
PEL TWA 100 ppm (850 mg/m3) See Appendix G The National Institute for Occupational Safety and Health (NIOSH)
REL 10 ppm (85 mg/m³) Occupational Safety and Health Administration (OSHA)
REL TWA 10 ppm (85 mg/m3) The National Institute for Occupational Safety and Health (NIOSH)
IDLH 700 ppm (NIOSH, 2024) CAMEO Chemicals
IDLH 700.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
IDLH 700 ppm Hazardous Substances Data Bank (HSDB)

These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.

08 · Physical and chemical properties

Tetraethyl silicate properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Tetraethyl silicate boiling point

Property Value Conditions Source
Boiling point 168.8 °C (335.8 °F) HSDB
168.89 °C (336 °F) NIOSH
168.89 °C (336 °F) at 760 mmHg CAMEO

Tetraethyl silicate melting point

Property Value Conditions Source
Melting point -82.5 °C (-116.5 °F) HSDB
-82.78 °C (-117 °F) NIOSH
-85.5 °C (-121.9 °F) CAMEO

Tetraethyl silicate density

Property Value Conditions Source
Density 0.93 g/cm³ NIOSH
0.933 g/cm³ at 20 °C HSDB
7.8 g/cm³ at 20 °C HSDB

Tetraethyl silicate solubility

Property Value Conditions Source
Solubility Soluble in ether HSDB
Slightly soluble in benzene HSDB
Decomposes in water decomposes HSDB

Tetraethyl silicate vapor pressure

Property Value Conditions Source
Vapor pressure 1 mmHg NIOSH
1 mmHg at 20 °C HSDB
1.88 mmHg at 25 °C HSDB

Tetraethyl silicate flash point

Property Value Conditions Source
Flash point 51.67 °C (125 °F) HSDB
37.22 °C (99 °F) HSDB
37 °C (98.6 °F) HSDB

Tetraethyl silicate lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) 1.3 % by volume HSDB

Tetraethyl silicate upper explosive limit (UEL)

Property Value Conditions Source
Upper explosive limit (UEL) 23 % by volume HSDB

Tetraethyl silicate vapor density

Property Value Conditions Source
Vapor density 7.22 (air = 1) HSDB

Tetraethyl silicate odor threshold

Property Value Conditions Source
Odor threshold 85 ppm HSDB
Water: decomposes in water; air: 17 uL/L; odor safety class D; D = 10-50% of distracted persons can detect TLV concn in the air. decomposes HSDB
Odor Threshold Low: 3.6 [ppm] Haz-Map

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

09 · Fire and explosion

Tetraethyl silicate fire and explosion behaviour

These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.

Tetraethyl silicate fire potential

Flammable liquid when exposed to heat or flame; can react vigorously with oxidizing materials.

Source: Hazardous Substances Data Bank (HSDB)

10 · Handling and storage

Tetraethyl silicate storage and handling

Tetraethyl silicate safe storage

Fireproof. Separated from acids and oxidants. Cool. Dry. Keep in a well-ventilated room.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Tetraethyl silicate storage conditions

Ethyl silicate must be stored to avoid contact with strong oxidizers (such as chlorine, bromine, and fluorine) since violent reactions occur. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in tightly closed containers in a cool, well-ventilated area away from water. Sources of ignition, such as smoking and open flames, are prohibited where ethyl silicate is handled, used, or stored. Metal containers involving the transfer of five gallons or more of ethyl silicate should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. Use only non-sparking tools and equipment, especially when opening and closing containers of ethyl silicate.

Source: Hazardous Substances Data Bank (HSDB)

Tetraethyl silicate incompatible materials

Strong oxidizers, water [Note: Reacts with water to form a silicone adhesive (a milky-white mass)].

Source: Hazardous Substances Data Bank (HSDB)

Tetraethyl silicate reactivity

ETHYL SILICATE reacts exothermically with acids Strong oxidizing acids may cause a reaction that is sufficiently exothermic to ignite the reaction products. May generate with caustic solutions. May generate flammable hydrogen with alkali metals and hydrides.

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Tetraethyl silicate in the storage compatibility matrix →

11 · Transport

Tetraethyl silicate UN number and transport classification

Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.

Tetraethyl silicate under UN 1292 — shipping name, class and packing group

Europe · ADR 2025, Table A

Proper shipping name (3.1.2) Class Classification code PG Labels (column 5)
TETRAETHYL SILICATE 3 F1 III
  • ADR label model 3 — Flammable liquid
3

Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 3 is “Flammable liquids” (ADR 2.1.1.1).

Proper shipping name (column 2) Class or division PG Labels (column 6)
Tetraethyl silicate 3 III
  • US DOT FLAMMABLE LIQUID label (§172.419)
3

Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 3 is “Flammable and combustible liquid” (49 CFR 173.2).

Full UN 1292 entry — special provisions, packing instructions, quantity limits and the orange plate →

12 · Questions

Tetraethyl silicate — frequently asked questions

What is the CAS number of Tetraethyl silicate?

The CAS number of Tetraethyl silicate is 78-10-4. Its EC number is 201-083-8.

What is the chemical formula of Tetraethyl silicate?

The molecular formula of Tetraethyl silicate is C8H20O4Si and its molecular weight is 208.33 g/mol.

What does a Tetraethyl silicate label have to show?

Under CLP Annex VI the label for Tetraethyl silicate carries the pictograms Flame and Exclamation mark and the signal word is Warning.

Is Tetraethyl silicate flammable?

Yes. CLP Annex VI assigns Tetraethyl silicate H226 — flammable liquid and vapour. The flash point reported for it is 51.67 °C (125 °F) (HSDB).

Is Tetraethyl silicate a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Tetraethyl silicate. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health.

What is the exposure limit for Tetraethyl silicate?

The US occupational exposure limit reported for Tetraethyl silicate is 100.0 [ppm] (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.

What is the boiling point of Tetraethyl silicate?

The boiling point reported for Tetraethyl silicate is 168.8 °C (335.8 °F) (HSDB).

What is the melting point of Tetraethyl silicate?

The melting point reported for Tetraethyl silicate is -82.5 °C (-116.5 °F) (HSDB).

How should Tetraethyl silicate be stored?

CLP Annex VI assigns Tetraethyl silicate the storage statement P403. Ethyl silicate must be stored to avoid contact with strong oxidizers (such as chlorine, bromine, and fluorine) since violent reactions occur. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in tightly closed containers in a cool, well-ventilated area away from water. Sources of ignition, such as smoking and open flames, are prohibited where ethyl silicate is handled, used, or stored. Metal containers involving the transfer of five gallons or more of ethyl silicate should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. Use only non-sparking tools and equipment, especially when opening and closing containers of ethyl silicate. (Hazardous Substances Data Bank (HSDB))

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