Danger Vs. Warning – OSHA/GHS Labeling

Understanding the difference between Danger and Warning can help you easily identify the hazards you may encounter while working with various chemicals.

The new GHS labeling system gone into effect on June 1st, 2016, has specific guidelines that employers need to adhere to in regards to the labeling of hazardous chemicals.

One of these new guidelines is the use of a “signal word” to immediately alert the user of potential risks associated with the chemical. This signal word can only be 1 of 2 approved words set by the GHS:

Warning and Danger.

Although these words may seem interchangeable, if you read the appendices OSHA published in depth, the differences between the two become apparent.

WARNING  identifies chemicals and products that present a lesser, but still potentially harmful, degree of hazard.

DANGER identifies chemicals and products that present a great, often immediate hazard, to the person handling the chemical.


Appendix C of the revised HazCom standard goes into more specifics. (1)

For example, you will see that the signal word depends on the hazard category that the particular chemical belongs too. Materials/Chemicals that fall into categories 1, 2 and 3 (C.4.1)  are known to cause Oral Acute Toxicity meaning they are toxic or lethal if ingested, this characterization means that the chemical requires the use of the more hazardous signal word, DANGER. Category 4 materials are “harmful” thus needing the lesser hazardous signal word, WARNING.

Another example is from section 4.4 of appendix C, this category emphasizes the differences between corrosive and irritant. If the product is only an irritant to skin and eyes then it is considered “harmful” and the signal word used would be WARNING, but if the product is considered corrosive (can cause permanent damage) to the eyes/skin then the product would be marked with DANGER.

There is also a category for flammable and combustible liquids. All flammable liquids are marked with DANGER while combustible liquids are marked with WARNING.  Combustible liquids have a higher flash-point and are less likely to ignite at room temperature, thus marked with the lesser of the two signal words.  

Other specific criteria for labeling based on the physical and health hazards of the chemical can be found in Appendix A and B of the new Hazard Communication standard.

By using only two “signal words” the risk of confusion is lessened and the differences in potentially harmful chemicals are more distinguishable.

If you would like more information regarding signal words and the new regulations, please check out the OSHA website: https://www.osha.gov/dsg/hazcom/ghs-final-rule.html

For HCL’s library of over 800 ready-made GHS chemical safety labels, click the button below!


(1) https://www.osha.gov/dsg/hazcom/hazcom-appendix-c.html


Leave a Reply