Environmental Health and Safety

MSDS Glossary

Odor
A description of the smell of the substance.
Odor Threshold
The lowest concentration of a substance's vapor, in air, that can be smelled.
Olfactory
Relating to the sense of smell.
Oral
Used in or taken into the body through the mouth.
Oral Toxicity
Adverse effects resulting from taking a substance into the body by mouth.
Organic Peroxide
An organic compound that is an oxidizer and contains the bivalent -O-O- structure and may be considered a structural derivative of hydrogen peroxide where one or both of the hydrogen atoms has been replaced by an organic radical.
OSHA
Occupational Safety and Health Administration, U.S. Department of Labor.
Overexposure
Exposure to a hazardous material beyond the allowable exposure limits.
Oxidizer
A substance that readily yields oxygen to or accepts electrons from another substance. By yielding oxygen or accepting electrons, an oxidizer can easily cause or enhance the combustion of other materials. Examples of oxidizers include bleach, which contains sodium hypochlorite, concentrated hydrogen peroxide (greater than 30%), and ammonium nitrate.

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