Sodium Hypochlorite: What Is It?

Figure 1. Clorox bottles.

Source: Firestone, A. Clorox Bottles. https://upload.wikimedia.org/wikipedia/commons/d/d3/Clorox_Bleach_products.jpg (accessed Feb 10, 2018). Copyright 2015 by A. Firestone.

Sodium hypochlorite or NaClO (sodium, chlorine, and oxygen) is the main ingredient in liquid bleach [1]. This product can be used at home as a cleaner, to generalize. More specifically, it can be used as a drain cleaner, mold remover, and hard surface cleaner [2]. In terms of using it strictly for laundry, it is used to clean and whiten clothing [2]. Sodium hypochlorite is also commonly used as a water disinfectant. I am sure we are all aware that pools have chlorine in them. Chlorine disinfects pools. Well, sodium hypochlorite is very similar to chlorine, and it is also used to disinfect pools. Approximately 3 to 6% concentration of sodium hypochlorite is typically present in household products while up to 30% is present when it is used industrially [1]. What a huge difference! 

We typically see bleach in its liquid form at different stores. This is because sodium hypochlorite is most stable as a liquid [1]. When it is not in its liquid form, it is called anhydrous; which means "lacking water" [1]. Normally, sodium hypochlorite is tremendously unstable in its anhydrous form, so it is not typically found in its non-solution form. Even though sodium hypochlorite is a very useful chemical, it is fairly toxic. It has a pH of 11 (very basic), which makes it extremely irritating [3]. Avoiding inhalation of sodium hypochlorite is very important because it can irritate your nose, lungs, and throat [1]. Unfortunately, fluid may build-up in the lungs if exposure to sodium hypochlorite is high [4]. There is a higher threat of these toxicity effects on industrial products rather than household products since the concentration of sodium hypochlorite is higher in industrial products (30%) [1]. The more concentrated sodium hypochlorite is in the product you are using, the more toxic it will be (which is basic common sense) [5].

Chlorine (Cl2) and sodium hydroxide (NaOH) combine to create sodium hypochlorite (NaClO). The by-products, which are the other products made aside from sodium hypochlorite, are water (H2O) and salt (NaCl). Sodium hydroxide, clearly, has an 'OH' in its formula which is a hydroxide. This means it is very basic, which is ideally why sodium hypochlorite is basic with a pH of 11. Sodium hypochlorite is also a strong oxidizer (very reactive) [4]. This means it will react strongly with metals and organic metals [1]. 

To conclude, sodium hypochlorite is a very useful product. It may be quite toxic, but it keeps things clean!

References:

[1] Schlager, N.; Weisblatt, J.; Newton, D.E. Chemical Compounds [Online]; UXL: Detroit, MI, 2006; pg 759-763. http://go.galegroup.com.libproxy.mtroyal.ca/ps/retrieve.do?tabID=T003&resultListType=RESULT_LIST&searchResultsType=SingleTab&searchType=AdvancedSearchForm&currentPosition=1&docId=GALE%7CCX3441700189&docType=Topic+overview&sort=RELEVANCE&contentSegment=&prodId=GVRL&contentSet=GALE%7CCX3441700189&searchId=R1&userGroupName=mtroyalc&inPS=true&authCount=1&u=mtroyalc (accessed Feb 10, 2018).

[2] Vuong, B.; Tran, J. Sodium Hypochlorite. https://sodiumhypochlorite-bleach.weebly.com/works-cited.html (accessed Feb 10, 2018).

[3] Disinfectants Sodium hypochlorite, n.d. Lenntech. https://www.lenntech.com/processes/disinfection/chemical/disinfectants-sodium-hypochlorite.htm (accessed Feb 10, 2018).

[4] New Jersey Department of Health. Hazardous Substance Fact Sheet, 2000. http://nj.gov/health/eoh/rtkweb/documents/fs/1707.pdf (accessed Feb 10, 2018).

[5] Canadian Centre for Occupational Health and Safety. Sodium Hypochlorite, 2016. CHEMINFO. http://ccinfoweb2.ccohs.ca.libproxy.mtroyal.ca/cheminfo/records/351E.html (accessed Feb 10, 2018).