227692 Aldrich

Sulfur trioxide

contains stabilizer, ≥99%

Synonym: Sulfuric anhydride



Related Categories Chemical Synthesis, Oxidizing Agents, Sulfur-Based, Synthetic Reagents
vapor density   2.8 (vs air)
vapor pressure   280 mmHg ( 25 °C)
assay   ≥99%
contains   stabilizer
impurities   low-melting solid polymer (the formation of which is unavoidable)
bp   44.7 °C(lit.)
mp   16.8 °C(lit.)
density   1.97 g/mL at 25 °C(lit.)


Frequently Asked Questions

Frequently Asked Questions are available for this Product.

Price and Availability

Safety & Documentation

Safety Information

Signal word 
Hazard statements 
Precautionary statements 
Supplemental Hazard Statements 
Reacts violently with water.
UN1829 - class 8 - PG 1 - Sulphur trioxide, stabilized
WGK Germany 

Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis. These documents are located on the product detail page under Useful Links & Tools. Click on the following link to search for a Certificate of Analysis. Please click the following link to see the details on our Product Dating Information.
How do I get lot-specific information or a Certificate of Analysis?
A Certificate of Analysis is available by lot number and can be obtained through our Advanced Search Option:
How do I find price and availability?
There are several ways to find pricing and availability for our products.  Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers. 
Is Product 227692, Sulfur trioxide, OK to use if it contains solids?
This product may contain low-melting solid polymer, which is unavoidable. If the material is not completely liquid, place the bottle in a glass beaker or metal pail and warm under heat lamp or in an oven at 35ºC. DO NOT OVERHEAT! This product boils at 44.7ºC. Melting may take up to one week. When the material is liquid, it is ready for use.
What is the stabilizer used in Product 227692, Sulfur trioxide?
The manufacturer considers the identity of the stabilizer to be proprietary information.
Why does Product 227692, Sulfur trioxide, contain a stabilizer?
The stabilizer is present to facilitate melting, not to prevent polymerization.
How is Product 227692, Sulfur trioxide, packaged?
This product is packaged in a screw-capped glass bottle.
How do I handle Product 227692, Sulfur trioxide, safely?
Technical Bulletin AL-141, which contains instructions for handling stabilized sulfur trioxide, can be accessed through the following link:
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS. To access the shipping information for this material, use the link on the product detail page for the product, or search here. 
My question is not addressed here, how can I contact Technical Service for assistance?
Use the option to the right to "Ask a Question" by email of a Technical Service Scientist.
Show more questions
Protocols & Articles
Peer-Reviewed Papers


Related Products

Technical Service:

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Bulk Ordering & Pricing:

Need larger quantities for your development, manufacturing or research applications?