Class I

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

• Class 1 (disambiguation)
• I class (disambiguation)