Chemical Reactivity Worksheet
Photo: Several rail cars partially submerged in a creek.
A train derailment in Paulsboro, N.J. in November 2012 released 23,000 gallons of toxic vinyl chloride gas. (NOAA)

The Chemical Reactivity Worksheet (CRW) is a free software program you can use to find out about the chemical reactivity of thousands of common hazardous chemicals.

Warning symbol Warning:  Two major bugs have been identified in the most recent version of the Chemical Reactivity Worksheet (CRW) 3.0. Learn more.

Download the Chemical Reactivity Worksheet for Windows, Mac, or iPad.

Reactivity is the tendency of substances to undergo chemical change, which can result in hazards—such as heat generation or toxic gas byproducts. The CRW predicts possible hazards from mixing chemicals and is designed to be used by emergency responders and planners, as well as the chemical industry, to help prevent dangerous chemical incidents.

The chemical datasheets in the CRW database contain information about the intrinsic hazards of each chemical and about whether a chemical reacts with air, water, or other materials. It also includes case histories on specific chemical incidents, with references.

You can also create your own custom chemical datasheets, as you might do, for instance, if your facility produces a proprietary chemical that is not in the CRW database.

The CRW also includes a reactivity prediction worksheet that you use to virtually "mix" chemicals to simulate accidental chemical mixtures, such as in the case of a train derailment, to learn what dangers could arise from the accidental mixing. For example, if the reaction is predicted to generate gases, the CRW will list the potential gaseous products, along with literature citations related to the prediction.

Screenshot of a chemical search in the Mixture Manager screen of the Chemical Reactivity Worksheet.
The Mixture Manager screen allows you to search for chemicals in the CRW's database, see a preview of the information on the chemical datasheets, and create a virtual mixture of chemicals. You can also access all the other features of the program from this screen, including the Compatibility Chart and hazards report for any mixture you create, reference information about the reactive groups used in the CRW, and information about absorbent incompatibilities with certain chemicals.
Screenshot of the Compatibility Chart in the Chemical Reactivity Worksheet, showing the predicted hazards of mixing a number of chemicals.
The Compatibility Chart shows the predicted hazards of mixing the chemicals in a mixture in an easy-to-use graphical interface. The reactivity predictions are color coded, and the cells on the chart can be clicked to find more information about specific predicted reactions. General hazard statements, predicted gas products, and literature documentation for the selected pair of chemicals are shown at the bottom of the chart.

More Information about the Chemical Reactivity Worksheet

NOAA has partnered with chemical industry experts to release a major update to the CRW (CRW version 3.0). This newest version of the program is the result of a two-year-long collaboration between NOAA chemical response specialists and expert chemists from the Dow Chemical Company.

All versions of the Chemical Reactivity Worksheet (CRW) were developed by NOAA's Office of Response and Restoration, in collaboration with the Environmental Protection Agency and the Center for Chemical Process Safety.

Chemical Reactivity Worksheet Fact Sheet [PDF, 967 KB]: Learn more about basic features of the CRW in this short fact sheet.

CAMEO Software Suite: Find out more about the several other programs in the CAMEO software suite related to the Chemical Reactivity Worksheet.

Questions: Contact us with questions, comments, or suggestions about the Chemical Reactivity Worksheet.