|Year : 2017 | Volume
| Issue : 1 | Page : 66-69
Soaps and infection control: From chemistry to microbiology
Gaurav Goel1, Sanjay Bhattacharya1, Mammen Chandy2
1 Department of Microbiology, Tata Medical Center, Kolkata, West Bengal, India
2 Department of Clinical Hematology and Medical Administration, Tata Medical Center, Kolkata, West Bengal, India
|Date of Web Publication||15-Jun-2017|
Tata Medical Center, 14 Major Arterial Road (EW), New Town, Kolkata - 700 156, West Bengal
Source of Support: None, Conflict of Interest: None
Context: Soap and water cleaning of hands and body surfaces is one of the primary aspects of infection prevention and control. A systematic study of commonly used soaps is lacking.
AIMS: To investigate: (a) whether the so-called medicated soaps have a composition which is significantly different from ordinary soaps, (b) whether the ingredients responsible for enhanced antimicrobial activity posed any health risk and (c) whether the medicated soaps offered any specific advantages over non-medicated soaps.
Settings and Design: Study was done with soaps available in Indian market, used predominantly in community settings but also in hospitals.
Materials and Methods: Chemical composition was checked from package labels. No chemical or microbiological tests were done to verify actual composition against stated composition. Maximum retail prices as mentioned on the pack label were noted.
Statistical Analysis Used: None.
Results: Soaps contain a multiplicity of ingredients. Exact composition is unknown as none of the soaps studied mentioned percentages. A number of antimicrobial agents were identified in soaps, which included salts of ethylenediaminetetraacetic acid, sodium chloride, triclocarban, triclosan, cresol compounds and certain quaternary ammonium compounds. No clear advantage was noted of the so-called ‘medicated soap’ over ‘non-medicated soaps’ in terms of ingredients or their actions. Certain medicated soaps may contain ingredients which may have a deleterious effect on microbial flora (generation of resistance) or human health (enzyme inhibition).
Conclusion: While purchasing soaps either for domestic use or for hospital infection control, we need to pay due attention to its composition.
Keywords: Chemistry, infection prevention, microbiology, safety, soaps
|How to cite this article:|
Goel G, Bhattacharya S, Chandy M. Soaps and infection control: From chemistry to microbiology. J Acad Clin Microbiol 2017;19:66-9
| Introduction|| |
Soap and water cleaning of hands and body surfaces is one of the primary aspects of infection prevention and control. Soaps contain surface-active agents, which reduce surface tension and help cleaning oily substances and dirt. Some soaps may contain ingredients which could have antibacterial activity. These may be described as medicated soaps. Purpose of the present study was to investigate: (a) whether the so-called medicated soaps have a composition which is significantly different from ordinary soaps, (b) whether the ingredients responsible for enhanced antimicrobial activity posed any health risk and (c) whether the medicated soaps offered any specific advantages over non-medicated soaps.
The study was conducted as part of an exercise for determining the preferred soap (meant for personal use of patients) for the hospital pharmacy in a cancer hospital in eastern India.
| Materials and Methods|| |
Some commonly used soaps available in the Indian market were chosen including one medicated soap present at the hospital pharmacy. The ingredient of various soaps as mentioned over the packet was studied (maximum retail prices were from the period 2013-2014, when the study was done). PubMed and Google search engines were used to find relevant references with respect to ingredient known to have antimicrobial activity. No chemical or microbiological tests were done to verify actual composition against stated composition.
| Results|| |
Study showed that soaps contain many ingredients [Table 1]. Exact composition is unknown as none of the soaps studied mentioned percentages or proportions. A number of antimicrobial agents were identified in soaps, which included salts of ethylenediaminetetraacetic acid (EDTA), sodium chloride, triclocarban (TCC), triclosan, cresol compounds, certain quaternary ammonium compounds, flower and leaf extracts. The antimicrobial effect of leaf and flower extracts has not been assessed in this analysis. Certain important aspects of the ingredients known to have antimicrobial activity were as follows:
|Table 1: Comparative study of some common “medicated” and “non-medicated” soap in India|
Click here to view
Activity of this compound is higher against Gram-negative bacteria than for Gram-positive bacteria (present in Lifebuoy, Margo, Lux and Dove).
This compound has broad-spectrum antibacterial activity. Certain salts of EDTA have activity against metallo-beta-lactamase producers (such as some carbapenemase-producing Gram-negative bacilli) (present in most soap studied except Margo).
High-level tolerance to triclosan may play a role in antibiotic resistance in certain bacteria (present in Apollo Pharmacy antibacterial soap and Savlon soap).,
This is a disinfectant and is a potent inhibitor of the enzyme epoxide hydrolase (sEH) (present in Lifebuoy [bar + liquid] and Dettol bar soap). Epoxide hydrolase is distributed in a number of organs and tissues including the liver, kidney and brain.
| Discussion|| |
Cleanliness is an essential part of infection control measures. Soap and water are basic components used in cleaning practices. However, the selection of soap and water of appropriate quality is not always done with diligence. The effect of water on its own is significant, and according to one study, it was more compared to liquid soap alone or Savlon in water. Washing hands or body parts with clean and chemically and microbiologically safe water seems to be fundamental in the cleaning process taking away 80%–90% of bacterial and viral load.
The active ingredients of soaps vary. In this study, the exact composition (in terms of proportions or weights) was available in none of the soaps. Some soaps may contain substances which cause skin irritation. Certain medicated soaps may contain ingredients which may have a deleterious effect on microbial flora (generation of resistance) or human health (enzyme inhibition).,,,,,, Side effects caused by soaps may differ. In one study, Lifebuoy soaps had the highest erythema score.
The use of antibacterial agents in the soaps seems to be widespread. In our study, five out of nine soaps reviewed found the ingredients to contain either triclosan or TCC. This is similar to a study done in the United States where 45% of surveyed soaps were found to contain antibacterial agents. No clear advantage was noted for the so-called ‘medicated soap’ over ‘non-medicated soaps’ in terms of ingredients or their actions. Dettol and Lifebuoy soaps have similar compositions with the extra presence of sodium chloride in Lifebuoy soap. Sodium chloride is known to have an inhibitory action on Gram-negative bacilli. However, many non-medicated soaps also have ingredients which are similar. Savlon may contain different ingredients in different formulations and countries (Triclosan in Savlon soaps in India and chlorhexidine in Savlon solution abroad). If we are to choose amongst the medicated soaps, we should avoid those containing Triclosan (because there is some evidence that they can lead to antibiotic resistance in Gram-negative bacilli).
The current study is based on literature review from the package labels on soaps and information available in medical literature. It does not involve actual microbiology experiments done with the soaps that have been discussed. This is a limitation of this study. The primary aim of the current literature review is to increase awareness in the medical, scientific community and the lay public. Performing practical microbiology experiments would give us a better understanding and has been done in a study from Saudi Arabia and Egypt which reported that Lifebuoy antibacterial handwash (containing TCC) and Palmolive hygiene handwash (containing unspecified ‘natural’ active ingredients) were superior (in terms of microbiological efficacy in reducing bacterial counts in vitro) compared with other handwashes, whereas amongst the soaps, CAREX was the superior brand. The same study also generalised that the TCC-containing handwashes seemed to be more effective than chloroxylenol-containing handwashes. However, it also added that TCC has also been shown to have significant absorption into the human body after showering and may have some effects in inhibiting human enzymes.
Many questions remain unanswered at the end of the study. These include (a) what is the exact composition of soaps, (b) are the ingredients which are potentially harmful present in soaps within acceptable limits and (c) what are the long-term consequences of their use? The selection of soaps unlike antibiotics or disinfectants is often not done based on scientific merits and demerits. Advertising, availability and individual perceptions and preferences play a major role in selection. It is important that in the process of selection of soaps either by healthcare administrators for institutional use or by others for domestic use, scientific understanding overrides cosmetic perceptions. This may ensure that undesirable effects are minimised, and expensive materials with no real additional advantage are not purchased. Bar soaps although not commonly used in developed countries are still widely used in developing countries because of low cost (note in the current analysis, liquid soaps were more expensive per pack than bar soaps) and long duration cultural familiarity.
While we select our soaps, it appears that economic, cosmetic, social consciousness and cultural considerations play a more dominant part than hard scientific facts. This needs to change, and regulations need to be more stringent with regard to safety and stated efficacy of soaps. The current study we hope would help to increase awareness amongst soap users in India.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Ansari SA, Sattar SA, Springthorpe VS, Wells GA, Tostowaryk W.In vivo
protocol for testing efficacy of hand-washing agents against viruses and bacteria: Experiments with rotavirus and Escherichia coli
. Appl Environ Microbiol 1989;55:3113-8.
Voss JG. Effects of an antibacterial soap on the ecology of aerobic bacterial flora of human skin. Appl Microbiol 1975;30:551-6.
Lin B, McCormick AV, Davis HT, Strey R. Solubility of sodium soaps in aqueous salt solutions. J Colloid Interface Sci 2005;291:543-9.
Lanigan RS, Yamarik TA. Final report on the safety assessment of EDTA, calcium disodium EDTA, diammonium EDTA, dipotassium EDTA, disodium EDTA, TEA-EDTA, tetrasodium EDTA, tripotassium EDTA, trisodium EDTA, HEDTA, and trisodium HEDTA. Int J Toxicol 2002;21 Suppl 2:95-142.
Dinkela A, Ferié J, Mbata M, Schmid-Grendelmeier M, Hatz C. Efficacy of triclosan soap against superficial dermatomycoses: A double-blind clinical trial in 224 primary school-children in Kilombero District, Morogoro Region, Tanzania. Int J Dermatol 2007;46 Suppl 2:23-8.
D’Arezzo S, Lanini S, Puro V, Ippolito G, Visca P. High-level tolerance to triclosan may play a role in Pseudomonas aeruginosa
antibiotic resistance in immunocompromised hosts: Evidence from outbreak investigation. BMC Res Notes 2012;5:43.
Tarnow P, Tralau T, Hunecke D, Luch A. Effects of triclocarban on the transcription of estrogen, androgen and aryl hydrocarbon receptor responsive genes in human breast cancer cells. Toxicol In Vitro
Morisseau C, Hammock BD. Impact of soluble epoxide hydrolase and epoxyeicosanoids on human health. Annu Rev Pharmacol Toxicol 2013;53:37-58.
Lakshmi C, Srinivas CR, Anand CV, Mathew AC. Irritancy ranking of 31 cleansers in the Indian market in a 24-h patch test. Int J Cosmet Sci 2008;30:277-83.
Ogunshe AA, Omotoso OA, Akindele TM. Soaps and germicides as adjunct topical antimycotic agents on Candida
species implicated in vulvovaginal candidasis. East Afr J Public Health 2011;8:112-8.
Schebb NH, Inceoglu B, Ahn KC, Morisseau C, Gee SJ, Hammock BD. Investigation of human exposure to triclocarban after showering and preliminary evaluation of its biological effects. Environ Sci Technol 2011;45:3109-15.
Andersen A. Final report on the safety assessment of sodium p-chloro-m-cresol, p-chloro-m-cresol, chlorothymol, mixed cresols, m-cresol, o-cresol, p-cresol, isopropyl cresols, thymol, o-cymen-5-ol, and carvacrol. Int J Toxicol 2006;25 Suppl 1:29-127.
Connor TH, Tee PG, Afshar M, Connor KM. Mutagenicity of cosmetic products containing Kathon. Environ Mol Mutagen 1996;28:127-32.
Perencevich EN, Wong MT, Harris AD. National and regional assessment of the antibacterial soap market: A step toward determining the impact of prevalent antibacterial soaps. Am J Infect Control 2001;29:281-3.
Kaliyadan F, Aboulmagd E, Amin TT. Antimicrobial activity of commercial “antibacterial” handwashes and soaps. Indian Dermatol Online J 2014;5:344-6.
] [Full text]