Class I may refer to:
- Class I antiarrhythmic
 - Class I electrical appliance, a device constructed according to electrical grounding specifications in the IEC 60536-2 standard
 - Class I bacteriocin, a type of toxin produced by some bacteria
 - Class I biosafety cabinet
 - Class I laser, a type of eye-safe laser defined in the ANSI Z136 standard
 - Class I rail carrier, a type of major freight railroad company in Canada
 - Class I railroad, a type of major freight railroad company in the United States
 
See also
    This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.