Editing Urinal deodorizer block

{{See also|Toilet rim block}}
{{Short description|Small disinfectant block added to urinals}}
{{MCN|date=April 2024}}
[[Image:Urinal with urinal cake gsu cit 2004.jpg|thumb|right|A pink deodorizer block + urinal screen in a urinal at [[Georgia Southern University]]]][[File:Waterless urinal in City University of Hong Kong.jpg|thumb|A Johnson Suisse [[waterless urinal]] with a block placed above the drain at [[City University of Hong Kong]]]]'''Urinal deodorizer blocks''' (commonly known as '''urinal cakes''', '''urinal cookies''', '''urinal biscuits''' (or jocularly '''piscuits'''), '''urinal donuts''', '''toilet lollies''', '''trough lollies''', '''urinal pucks''', '''toilet pucks''', or '''urinal peons''' (alternately '''urinal pee-ons''')) are small [[disinfectant]] blocks or tablets that are added to [[Urinal (restroom)|urinal]]s. As these products originally contained [[1,4-Dichlorobenzene|para-dichlorobenzene]] (pDCB) they may also be called '''para blocks'''. Besides disinfecting, the purpose of these materials is to [[deodorize]] restroom urinals.<ref name="inf">{{cite web | publisher=INFORM | date=2009 | title=Fact Sheet on Respiratory Hazards and Restroom Deodorant Blocks | url=http://www.informinc.org/fact_P3restroom.php}}</ref> They are placed above the urinal drain, often in the confines of a small plastic device called a ''urinal screen'' that prevents loss down the drain when they dissolve down to a small size.

==Chemistry==
[[File:Para block.jpg|thumb|Para block]]
The chemicals composing the block vary. The original formulations were based upon [[naphthalene]] and then later [[para-dichlorobenzene]], both now known to be hazardous to health by inhalation.  In some areas, the use of para-dichlorobenzene-based blocks has been banned; in other areas para-dichlorobenzene blocks or "para blocks" are still used. {{Clarify|date=April 2024}} Para-dichlorobenzene- and naphthalene-based blocks do not readily dissolve in water/urine, but easily [[Sublimation (chemistry)|sublime]] into the air, creating a sickly-sweet odor that has anti-microbial effects.<ref name="Ross">{{Cite book | last1 = Rossberg | first1 = M. | last2 = Lendle | first2 = W. | last3 = Pfleiderer | first3 = G. | last4 = Tögel | first4 = A. | last5 = Dreher | first5 = E. L. | last6 = Langer | first6 = E. | last7 = Rassaerts | first7 = H. | last8 = Kleinschmidt | first8 = P. | last9 = Strack | first9 = H. | last10 = Cook | first10 = R. | last11 = Beck | first11 = U. | last12 = Lipper | first12 = K.-A. | last13 = Torkelson | first13 = T.R.| last14 = Löser | first14 = E. | last15 = Beutel | first15 = K.K. | last16 = Mann | first16 = T. | doi = 10.1002/14356007.a06_233.pub2 | chapter = Chlorinated Hydrocarbons | title = Ullmann's Encyclopedia of Industrial Chemistry | year = 2006 | isbn = 3527306730 }}</ref>

Many urinal blocks are now para-dichlorobenzene and [[naphthalene]] free; these water-soluble alternative blocks are made from a mixture of fragrances and [[surfactant]]s (normally [[quaternary ammonium compound]]s),<ref name=inf/>
which offer some active cleaning and antibacterial efficacy. The new water-soluble blocks improve the cleaning of the pipes which helps to reduce odor. 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 [[Trap (plumbing)|traps]] and pipes. Some manufacturers claim that these "biological blocks" can enable completely no-flush [[Urinal#Waterless urinals|waterless urinals]] to be fitted.

Some urinal blocks also have enzymes added to help digest buildup within pipes.{{CN|date=November 2020}}

Autoflush<ref name=inf/> and/or [[ice]] are sometimes used as alternatives.<ref>{{cite web|last=Upton|first=Chad|title=Why Bars Put Ice in the Urinals|url=http://brokensecrets.com/2013/07/31/why-bars-put-ice-in-the-urinals/|work=Broken Secrets|date=31 July 2013 |access-date=31 July 2013}}</ref>

==See also==
*[[Air freshener]]
*[[Toilet rim block]]

==References==
{{Reflist}}
{{Human waste elimination}}

{{DEFAULTSORT:Urinal Deodorizer Block}}
[[Category:Hygiene]]
[[Category:Toilets]]
[[Category:Cleaning products]]
[[Category:Urinals]]

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