Waterless urinal in City University of Hong Kong

Urinal deodorizer blocks (commonly known as urinal cakes, urinal cookies, urinal biscuits (piscuits), urinal donuts, toilet lollies, trough lollies, urinal mints, urinal pucks, hockey pucks, toilet pucks, or urinal peons (pee-ons) are small

disinfectant A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than s ...

blocks that are added to

urinal A urinal (, ) is a sanitary plumbing fixture for urination only. Urinals are often provided in public toilets for male users in Western countries (less so in Muslim countries). They are usually used in a standing position. Urinals can be ...

s. Those containing

para-dichlorobenzene 1,4-Dichlorobenzene (1,4-DCB, ''p''-DCB, or ''para''-dichlorobenzene, sometimes abbreviated as PDCB or para) is an organic compound with the formula C6H4Cl2. This colorless solid has a strong odor. The molecule consists of a benzene ring with ...

(pDCB) may be called para blocks. Besides disinfecting, the purpose of these blocks is to reduce or mask odors from restroom urinals. They are placed above the urinal drain, often in the confines of a small plastic trap (urinal screen) that prevents their loss down the drain when they dissolve to a small size.

Appearance

Urinal deodorizer blocks are tablets (usually cylindrical in shape).

Composition

The chemicals composing the block may vary. The original formulations were of

naphthalene Naphthalene is an organic compound with formula . It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromat ...

and later para-dichlorobenzene, both now known to be hazardous to health by inhalation. In some areas, the use of para-dichlorobenzene toilet blocks has been banned; in other areas para-dichlorobenzene blocks or "para blocks" are still used. Para-dichlorobenzene and naphthalene blocks do not readily dissolve in water or urine, but easily sublime into the air, creating a sickly-sweet odor and anti- mould and disinfectant effects. Many urinal blocks are now para-dichlorobenzene-free, water-soluble alternative blocks made from

surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsion#Emulsifiers , ...

s, which offer some active cleaning efficacy. The new water-soluble blocks improve the cleaning of the pipes to remove some of the cause of odor problems. Some recent formulations also include bacterial spores which, coupled with the surfactant cleaning power, can more completely get rid of odors and blockages caused by the buildup of solids in the traps and pipes. Some manufacturers claim that these "biological blocks" can enable completely no-flush waterless urinals to be fitted. Alternative toilet blocks may release a pleasant odor, but also support cleaning and disinfecting of toilet bowls and urinals, in contrast to para-dichlorobenzene, which does not have cleaning properties. The block's functionality is enhanced by saturating it with a scenting compound and

quaternary ammonium compound In chemistry, quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure , R being an alkyl group or an aryl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium catio ...

s. Some urinal blocks also have enzymes added to help digest the buildup within pipes. Autoflush and/or ice are sometimes used as alternatives.

References

{{DEFAULTSORT:Urinal Deodorizer Block Hygiene Toilets Cleaning products Urinals de:Klostein nl:Toiletblok pl:Kostka toaletowa

Appearance

Composition

See also

References