Comet is a powdered cleaning product and brand of related cleansing products. The brand was introduced in 1956 by Procter & Gamble, and was sold to Prestige Brands in 2001. Comet is now sold in North America and distributed in the United States by Prestige Brands. Procter & Gamble retained the rights to market the brand in Europe, and to the professional (non-home consumer) market in the USA.
According to the Material Safety Datasheets published by Procter and Gamble (P&G) (PGP Comet Deoderizing Cleanser with Chlorinol ) and Prestige Brands (Comet Powdered Cleanser), Comet contains 60-100% calcium carbonate. Other ingredients common to all Prestige Brands Comet Powdered Cleansers are listed as :
- Calcium Carbonate - Scrubbing Agent
- Calcium Hydroxide - pH Adjuster
- Green 7 - Colorant (except in Comet Lemon Powder)
- Sodium Carbonate - Builder/Sequestering Agent
- Sodium Linear Alkylbenzenesulfonate Surfactant - Cleaning Agent
- Trichloro-s-triazinetrione - Bleach
The P&G Professional Comet MSDS details percentages :
- Calcium Carbonate 60-100%
- Sodium Carbonate 7-13%
- Calcium Hydroxide 1-5%
- Sodium Dicholor-s Triazinetrione Dihydrate 1-5%
Not all ingredients are listed on an MSDS.
Mixing cleaners containing bleach or other oxygenates such as Comet with cleaners or other products that contain ammonia or acid is dangerous. The P&G Comet MSDS states "Avoid contact with acids. and Ammonia."
Despite being labeled as scratch free, its label also advises the use of plenty of water on delicate surfaces. Comet is not recommended for use on silver, painted surfaces, walls, soft plastic, aluminum and rubber.
In the 1960s and 1970s, Comet was known for a series of popular television ads featuring the character of "Josephine the Plumber" (portrayed by actress Jane Withers). Later, in the 1980s, she gained a niece named JoAnn or Jo, who, after helping her customers with their plumbing issues, would show them a picture of her beloved Aunt Josephine, who uttered, via voiceover, "Nothing can hold a can to Comet!".
In 1969, The Wacky Packages series included a mock ad, drafted by Art Spiegelman and painted by Tom Sutton, depicting a flag-waving American Revolutionary soldier and a pair of club-wielding policemen chasing a group of hippies carrying picket signs inscribed "For Freedom!" and "Love! Not War!", with a prominent slogan, "Keep America Clean with Commie Cleanser" and a can, depicting a caricature of Uncle Sam, and inscribed, "Extra Strong Commie Cleanser" and "Gets Rid of Reds, Pinkos, Hippies, Yippies & Flippies". The mock ad has also appeared depicting the can alone.
- Comet, it makes your face turn green
- Comet, it tastes like gasoline
- Comet, it makes you vomit,
- So get some Comet, and vomit today!
- Procter and Gamble Professional MSDS 
- Comet Brands Website
- Topps Wacky Ads Series: Commie Cleanser #30 - long perf