How to Make Sense of Material Safety Data


Material Safety Data Sheets must be available to employees and they must be trained to read them. Failure to abide by this rule set by the U.S. Occupational Safety and Hazard Agency is the second-most frequent employer violation. Even when MSDSs are available, few employees ever read them. Culturally, we believe instructions and warnings are a joke. Well, its your funeral … literally.


Available for any product containing hazardous ingredients, the MSDS (now known by the international SDS, or Safety Data Sheet) is your roadmap to safe use and to the physical and environmental characteristics of the product. There are many training guides on using these sheets ( is some general guidance on how to read between the lines.

If the composition is a trade secret (section 3) and basic physical properties (section 9) are not determined, don’t buy the product. The manufacture is not taking disclosure seriously. There can be logical exceptions, but in these cases they should say not applicable rather than not available.

Section 2: Hazards Identification. Read this in detail-although you may assume this information will be repeated in other sections, often it is not. For example, something can cause reproductive problems may not technically be considered toxic.

Section 3: Chemicals. You are going to need to look these up. In the example of a cleaner, some may be obvious; sodium carbonate is washing soda, and sodium citrate is simply neutralized citric acid, which is extracted from citrus fruits. Look for manufacturer SDS for ALL of the key ingredients; these SDS tend to be more clearly state the hazard.

Section 5. Fire Fighting. The flash point (the temperature above which there will be enough vapors in a confined space to explode) is one of the most accessible hints to relative ignitability. This may also be listed in section 9.

Section 9: Physical Properties.Excessive blanks here mean they arent trying or are being purposefully evasive. Errors are also too common. Kleen Strip Premium list the evaporation rate as

Section 12: Ecological Information. It is unacceptable for a company to claim a product is safe or green, and then not complete this section. If they can’t prove it, they shouldnt make the claim. Look for toxicity to marine organisms and quantitative statements about biodegradability. If nothing is listed, look up the SDS for key ingredients. For example, Soy Strip-which claims it is green- leaves the marine toxicity section blank. Meanwhile, the SDS for its main ingredient (NMP) is about 10-20 times more toxic than propylene glycol antifreeze.

For reference, LC/50 or EC/50 means 50 percent of hatchlings will die at the referenced concentration within the test period (48 or 72 hours). Soy Strip reports the following toxicity (daphnia are a water flea; the SDS should have listed the kind of fish).

Toxicity to Fish LC50 > 500 mg/l

EC50/48h/daphnia = > 1000 mg/l

EC50/72h/algae = > 500 mg/l

Section 13: Disposal Considerations. Most of the time the sheets say Follow local regulations, which is little help. For example, several producers of methyethylene chloride say follow local regulations, even though it is an EPA listed hazardous waste (F002) and will always be a hazardous waste, even after the waste is dry. Materials that are almost certainly non-hazardous can become contaminated in use. To be non-hazardous the pH after use must be 2-12.5, flash point above 140F, and it cannot contain certain listed or toxic materials. Liquids cannot go in the trash. Can it be recycled? Does it meet sewer requirements (read local sewer ordinance, available on-line). This EPA guidance explains hazardous waste determination.

Yes, the numbers and Latin names can be off-putting, but learning to read an MSDS is just as important as learning to read the ingredients on a frozen dinner.

Darrell Nicholson, editor of Practical Sailor, grew up boating on Miami’s Biscayne Bay on everything from prams to Morgan ketches. Two years out of Emory University, after a brief stint as a sportswriter, he set out from Miami aboard a 60-year-old wooden William Atkin ketch named Tosca. For 10 years, he and writer-photographer Theresa Gibbons explored the Caribbean, crossed the Pacific, and cruised Southeast Asia aboard Tosca, working along the way as journalists and documenting their adventures for various travel and sailing publications, including Cruising World, Sail, Sailing, Cruising Helmsman, and Sailing World. Upon his return to land life, Darrell became the associate editor, then senior editor at Cruising World magazine, where he worked for five years. Before taking on the editor’s position at Practical Sailor, Darrell was the editor of Offshore magazine, a boating-lifestyle magazine serving the New England area. Darrell has won multiple awards from Boating Writer’s International, including the Monk Farnham award for editorial excellence. He holds a U.S. Coast Guard 100-ton Master license and has worked as a harbor pilot and skippered a variety of commercial charter boats.


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