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

Dichlorodimethylsilane

Dichlorodimethylsilane is a colorless liquid with a sharp, like hydrochloric acid odor.

CAS 75-78-5 C2H6Cl2Si 129.06 g/mol Danger

01 · Identification

What Dichlorodimethylsilane is

Dichlorodimethylsilane is a colorless liquid with a sharp, like hydrochloric acid odor. Its molecular formula is C2H6Cl2Si and its molecular weight is 129.06 g/mol. It boils at 70.3 °C, melts at -16 °C.

Under the GHS it carries the signal word Danger. It is classed as corrosives.

02 · Identifiers

Dichlorodimethylsilane identifiers and molecular data

Dichlorodimethylsilane CAS number and EC number

CAS number75-78-5
EC number200-901-0
Index number (CLP Annex VI)014-003-00-X

Dichlorodimethylsilane molecular formula and molecular weight

Molecular formulaC2H6Cl2Si
Molecular weight129.06 g/mol
Chemical class Corrosives

Other names for Dichlorodimethylsilane

  • dimethyldichlorosilane

03 · GHS classification

Dichlorodimethylsilane hazard classification

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

Dichlorodimethylsilane pictograms and signal word

Signal wordDanger

Dichlorodimethylsilane hazard class and category

GHS hazard classes Dichlorodimethylsilane falls into
Hazard class Category From code Pictogram
Flammable liquids GHS chapter 2.6 Category 2 H225 GHS02
Skin corrosion/irritation GHS chapter 3.2 Category 2 H315 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

Dichlorodimethylsilane hazard statements (H-codes)

Hazard statements assigned to Dichlorodimethylsilane
CodeHazard statement
H225 Highly flammable liquid and vapour.
H335 May cause respiratory irritation.
H315 Causes skin irritation.
H319 Causes serious eye irritation.

This page lists only the codes assigned to Dichlorodimethylsilane. 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 Dichlorodimethylsilane

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 Dichlorodimethylsilane 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

Dichlorodimethylsilane precautionary statements

CLP Annex VI assigns 14 precautionary statements to Dichlorodimethylsilane. 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

Dichlorodimethylsilane 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 диметилдихлоросилан
Spanish español Dimetildiclorosilano
Czech čeština dichlordimethylsilan
Danish dansk dichlordimethylsilan
German Deutsch Dimethyldichlorsilan
Estonian eesti dimetüüldiklorosilaan
Greek ελληνικά διμεθυλοδιχλωροσιλάνιο
English English dimethyldichlorosilane
French français diméthyldichlorosilane
Croatian hrvatski dimetildiklorsilan
Italian italiano dimetildiclorosilano
Latvian latviešu dimetildihlorosilāns
Lithuanian lietuvių dimetildichlorsilanas
Hungarian magyar dimetil-diklór-szilán
Maltese Malti dimetildiklorosilan
Dutch Nederlands dimethyldichloorsilaan
Polish polski dichlorodimetylosilan
Portuguese português dimetildiclorossilano
Romanian română dimetildiclorosilan
Slovak slovenčina dichlórdi(metyl)silán
Slovenian slovenščina dikloro(dimetil)silan
Finnish suomi dimetyylidikloorisilaani
Swedish svenska dimetyldiklorsilan

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

Dichlorodimethylsilane GHS label elements

Everything CLP Annex VI fixes for Dichlorodimethylsilane, 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

Danger

Dichlorodimethylsilane

  • Highly flammable liquid and vapour.
  • May cause respiratory irritation.
  • Causes skin 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.
  • Wash thoroughly after handling.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF ON SKIN:
  • IF IN EYES:
  • Get medical advice/attention.
  • If skin irritation occurs:
  • If eye irritation persists:
  • Remove contact lenses, if present and easy to do. Continue rinsing.
  • Wash with plenty of water/
  • Store in a well-ventilated place.

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

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

07 · Health hazards

Dichlorodimethylsilane health hazards and exposure limits

Dichlorodimethylsilane hazard summary

Evolves HCl when spilled in water; [ERG 2016] Capable of causing second and third degree burns to eyes and skin; A severe mucous membrane and respiratory tract irritant; [HSDB] A corrosive substance that can cause pulmonary edema; [ICSC] Reacts with water; A corrosive substance that can cause injury to the skin, eyes, and respiratory tract; Inhalation may cause chemical pneumonitis; [MSDSonline] In lethal concentration studies, causes labored breathing, corneal opacities, and lung damage; [AIHA]

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

08 · Physical and chemical properties

Dichlorodimethylsilane 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.

Dichlorodimethylsilane boiling point

Property Value Conditions Source
Boiling point 70.3 °C (158.5 °F) HSDB
70 °C (158 °F) at 760 mmHg CAMEO
71 °C (159.8 °F) ICSC

Dichlorodimethylsilane melting point

Property Value Conditions Source
Melting point -16 °C (3.2 °F) HSDB
-86.11 °C (-123 °F) CAMEO
-76 °C (-104.8 °F) ICSC

Dichlorodimethylsilane density

Property Value Conditions Source
Density 1.1 g/cm³ CAMEO
1.07 g/cm³ ICSC
1.064 g/cm³ at 25 °C HSDB

Dichlorodimethylsilane solubility

Property Value Conditions Source
Solubility Soluble in benzene and ether HSDB
Solubility in water: reaction ICSC
Decomposes in water and ethanol decomposes HSDB

Dichlorodimethylsilane vapor pressure

Property Value Conditions Source
Vapor pressure 108.759 mmHg at 20 °C ICSC
144 mmHg at 25 °C HSDB

Dichlorodimethylsilane flash point

Property Value Conditions Source
Flash point -8.89 °C (16 °F) HSDB
-9 °C (15.8 °F) ICSC

Dichlorodimethylsilane autoignition temperature

Property Value Conditions Source
Autoignition temperature 380 °C (716 °F) HSDB
398.89 °C (750 °F) CAMEO

Dichlorodimethylsilane lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) 3.4 % by volume HSDB
5.5 % by volume HSDB

Dichlorodimethylsilane upper explosive limit (UEL)

Property Value Conditions Source
Upper explosive limit (UEL) 9.5 % by volume HSDB
10.4 % by volume HSDB

Dichlorodimethylsilane vapor density

Property Value Conditions Source
Vapor density 4.45 (air = 1) HSDB
4.4 (air = 1) ICSC

Dichlorodimethylsilane corrosivity

Property Value Conditions Source
Corrosivity Corrosive HSDB

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

09 · Fire and explosion

Dichlorodimethylsilane 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.

Dichlorodimethylsilane fire potential

Flammable and corrosive liquid. Vapors are heavier than air and may travel to sources ognition and flash back. Combustion by-products include hydrogen chloride.

Source: Hazardous Substances Data Bank (HSDB)

10 · Handling and storage

Dichlorodimethylsilane storage and handling

Dichlorodimethylsilane safe storage

Fireproof. Separated from incompatible materials. See Chemical Dangers. Cool. Dry. Keep under inert gas. Well closed.

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

Dichlorodimethylsilane storage conditions

SRP: Operations involving entry into tanks or closed vessels, and emergency situations, require consideration of potentially oxygen deficient, or "immediately dangerous to life and health" IDLH environments. This may necessitate use of a self-contained breathing apparatus (SCBA), or a positive pressure supplied air respirator.

Source: Hazardous Substances Data Bank (HSDB)

Dichlorodimethylsilane incompatible materials

Violent reaction on contact with water.

Source: Hazardous Substances Data Bank (HSDB)

Dichlorodimethylsilane reactivity

Chlorosilanes, such as DIMETHYLDICHLOROSILANE, are compounds in which silicon is bonded to from one to four chlorine atoms with other bonds to hydrogen and/or alkyl groups. Chlorosilanes react with water, moist air, or steam to produce heat and toxic, corrosive fumes of hydrogen chloride. They may also produce flammable gaseous H2. They can serve as chlorination agents. Chlorosilanes react vigorously with both organic and inorganic acids and with bases to generate toxic or flammable gases.

Source: CAMEO Chemicals

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

11 · Questions

Dichlorodimethylsilane — frequently asked questions

What is the CAS number of Dichlorodimethylsilane?

The CAS number of Dichlorodimethylsilane is 75-78-5. Its EC number is 200-901-0.

What is the chemical formula of Dichlorodimethylsilane?

The molecular formula of Dichlorodimethylsilane is C2H6Cl2Si and its molecular weight is 129.06 g/mol.

What does a Dichlorodimethylsilane label have to show?

Under CLP Annex VI the label for Dichlorodimethylsilane carries the pictograms Flame and Exclamation mark and the signal word is Danger.

Is Dichlorodimethylsilane flammable?

Yes. CLP Annex VI assigns Dichlorodimethylsilane H225 — highly flammable liquid and vapour. The flash point reported for it is -8.89 °C (16 °F) (HSDB).

Is Dichlorodimethylsilane a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Dichlorodimethylsilane. 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 boiling point of Dichlorodimethylsilane?

The boiling point reported for Dichlorodimethylsilane is 70.3 °C (158.5 °F) (HSDB).

What is the melting point of Dichlorodimethylsilane?

The melting point reported for Dichlorodimethylsilane is -16 °C (3.2 °F) (HSDB).

How should Dichlorodimethylsilane be stored?

CLP Annex VI assigns Dichlorodimethylsilane the storage statement P403. SRP: Operations involving entry into tanks or closed vessels, and emergency situations, require consideration of potentially oxygen deficient, or "immediately dangerous to life and health" IDLH environments. This may necessitate use of a self-contained breathing apparatus (SCBA), or a positive pressure supplied air respirator. (Hazardous Substances Data Bank (HSDB))

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