, ,

My apologies for not returning sooner to Mr. M. Manogaran’s interesting query left as a comment at
https://ykalaska.wordpress.com/2006/05/03/disinfectants-for-camp-field-and-household/ (Scrounging for funds interferes with interesting work.)

Kindly write to the %age proportion of Castor Oil Soap-35% being used to formulate Antiseptic Liquid Like Dettol.

I think the interest is in
* why is there soap in a disinfectant and
* why is the soap made from castor oil?

If I have failed to ask and/or answer your questions correctly please let me know. If anyone can provide additional references or a better discussion, please note in the comments.

Unfortunately, I am not an organic chemist so I can’t give great detail. But here is what I think is the short answer. The soap is used to keep the germicide (cresol or phenol) in solution until it is mixed with water for actual use (the cloudy mixed result indicates the phenol compound becoming suspended rather than dissolved). Soap is made from a fat or oil and an alkali. Castor oil has particular physical properties which make it a good molecule for making the soap to interact with the cresol/phenol molecule.

The liquid concentrate of Dettol ® and brown-bottle Lysol ® are composed of a phenol or cresol compound, alcohols, pine oil (Dettol®) and “other ingredients” which are soap, water, and caramel for coloring. When first introduced to Britain, the formula for Lysol was 50% cresol and the rest liquid soap. Lysol was so important that its commercial formula was legally established in the British Pharmacopoeia and in 1934 court standards “held that Lysol must contain 47 to 53 per cent. of cresols”. [“To use this [fake] article as a disinfectant might be worse than using none at all; its use would give a false feeling of security.”
http://www.rsc.org/delivery/_ArticleLinking/DisplayArticleForFree.cfm?doi=AN9345900691 (pdf file)]

I have added below some references for further examination but in particular the chemical references or databases used for the lay term lysol, Lysol ® and Dettol ®. I have tried at the end to give the identification numbers for the compounds under discussion. These ID numbers, for example the CAS number, are unique to a chemical compound. The use is similar to the binomial scientific name used to specify which of the very many different plants in different cultures that have the same common name.

CAS REGISTRY and CAS Registry Numbers. The CAS REGISTRY is the largest and most current database of chemical substances […] http://www.cas.org/expertise/cascontent/registry/regsys.html

These databases can also be searched for the chemical or toxic properties of other chemicals. The Chemical Abstract Service (CAS) the 100-year old database of the American Chemical Society, is an excellent resource but only available for a fee. There is a comparable US Pharmacopoeia (USP) and a British Pharmacopoeia (BP) but perhaps someone else can locate the Internet links to these databases.


Lysol / Dettol has a fascinating history. It would make an excellent honors thesis or science class project to use Lysol as the focus for understanding 19th century industrial chemistry (soap, salt, and hides/bones led to all sorts of advanced products), public health and medicine, and demographic transition (Lysol almost single-handedly extended women’s lifespans beyond pregnancy). [Has anyone done such a study?]

Wikipedia says the name Lysol comes from a combination of the words “lysosome” and “solvent” but it also says lysosomes weren’t discovered until 1949 (??) It is a modification of carbolic acid used by Dr. Lister to clean up surgical and gynecological procedures (i.e., surgeons, whose unwashed hands, frock coats, and instruments spread contaminating organisms between women giving birth).

I still have this image in my head of buckets of milky water being splashed down cobblestone city streets in Camus’ The Plague or Mann’s Death in Venice in order to prevent epidemics.

Lysol the consumer product is also an interesting access point to early 20th century advertising and cultural concepts of women and women’s role and the cultural meaning of “health”.

Through time, the Lysol and Dettol brands have changed their compositions. Lysol in particular has had its name appended to other types of disinfectants (the “quats” or quaternary compounds). Today it is difficult to find out about brown-bottle Lysol. In the USA it cannot be listed as a disinfectant because it has not been submitted to the Environmental Protection Agency for testing. The taxidermists and the museum/library conservationists have noted the changes in Lysol (substitutes of different phenolic compounds, addition of alcohols, a change in proportion of ingredients and the switch to the quaternary Lysol) which evidently affect how the material cleans or instead dissolves skin and any attached hair or feathers.

It would really be great if Reckitt Benckiser could provide a comprehensive history of the chemical composition. Many of the changes were for safety’s sake and others because of better materials available or maybe changes in consumer behavior. They have a broad time-line of the Colman Reckitt Benckiser Chiswick Lehn & Fink Products company(ies) of Lysol Dettol presented here
http://www.reckittbenckiser.com/RBTemplates/AboutUsOurHistory.aspx?pageid=15 Lysol is a German product imported first into Britain and then into the USA. [Does anyone have a reference to the German history? see end of post]

“Dettol is an aromatic compound derived from phenol, which contains a significant chlorine atom, helping us in our continuous fight against unwanted bacteria.” Molecule of the Month

…the word detergent has tended to imply synthetic detergent, or syndet for short, rather than the older soap. In fact, commercial formulations consist of a number of components, and we shall use the term surface-active agent, or it’s abbreviation surfactant, to describe the special active ingredients that give detergents their unusual properties. Soap, by this definition, is a surfactant. In fact, it is the oldest one and has been in use for over 4500 years.


The surfactant industry is a huge and dynamic business, and soap is just the start… Most familiar of all surfactants is soap, a simple substance which, in water, clearly demonstrates two effects. It produces foam due to its action at the air-water interface, and it makes the grease transfer from grubby hands into the soapy water as a result of its activity at the water-oil (grease) interface…. Soap was, and still is, made by the alkaline hydrolysis of animal fats or vegetable oils – a process known as saponification. Moving on from soaps – and into the 19th century – the next surfactants to be developed were the sulphates and sulphonates of vegetable oils. The reaction of castor oil with sulphuric acid is a classic example from the late 1800s. In this reaction the product is a mixture of sulphates and sulphonates which, after neutralisation with sodium hydroxide, give a product known as Turkey Red oil useful in the dyeing of linen.

… Micelles can act as solubilisers in which oily molecules of oil/grease/hydrocarbon are taken into the lipophilic core of the micelle and retained by the lipophile-to-lipophile attractive forces. By this means it is possible to make colloidal emulsions or microemulsions -sometimes called swollen micelles. An important application is to make a solvent such as a hydrocarbon ‘dissolve’ in water and surfactant. [I think this latter property is the key to the use of castor oil for Dettol / Lysol but my understanding is too poor to explain why.]


Castor oil soap
We’re talking about the oil from the castor bean plant, which isn’t a bean at all, [ Ricinus communis] and not the castor which comes from glands in the beaver mammal, Castor canadensis, once used for perfumes. Bill Casselman has an excellent disentanglement of “castor” and a photo of the nasty plant.

“In internal combustion engines, castor oil is renowned for its ability to lubricate under extreme conditions and temperatures, such as in air-cooled engines. The lubricants company Castrol takes its name from castor oil.” http://en.wikipedia.org/wiki/Castor_oil

Older Americans know of castor oil as a laxative or a “spring tonic” given to children. Look through the historical British Journal of Medicine for obsolete uses of castor oil and its soap for treatments during pregnancy. Fortunately, less harsh remedies are now available. Castor oil is not poisonous if carefully separated from the water soluble components of the castor seed.

Castor bean plants are sometimes used as an ornamental plant. In New Zealand, the neighbor behind me had an overgrown lot of immense castor plants, just a mess. The “beans” themselves are highly poisonous. Sometimes the seeds end up as beads for necklaces. The ingredient in Sarin gas (used in the Tokyo underground killings) is ricin which is derived from the plant.
Facts About Ricin cdc.gov

Castor oil is a “light” oil. Unfortunately, I don’t know the chemistry behind this. It does lead to interesting properties of the oil (see the Wikipedia article). I believe it may have been used once for oil immersion lenses in microscopy because of its purity, light refracting ability, and temperature range stability. It is less likely than some other oils to get “gummy” over time or with heat.

The castor oil can be made into a liquid soap. I ran across some 1911 data testing soap as an insecticide. Soaps will dissolve proteins or fats which form the coatings or walls of some microorganisms and will disrupt some insect coatings. Generally, the soap is not the germicide, the phenol compound is. I don’t know for sure, but I believe the soap may aid in maintaining the antiseptic cresol or phenol in solution.

The insecticidal value of soap alone is considerable, while its germicidal value is small…. Further tests showed that cocoanut-oil soap has the highest value as a germicide, a dilution of 1 : 40 killing the B. typhosus (twenty-four-hour culture) at 20 degrees C. in five minutes, while a dilution of only 1 : 20 was required in the case of castor- and olive-oil soaps to produce the same results. Insecticidal tests, using the bed-bug, Cirnex …

http://www.rsc.org/delivery/_articlelinking/displayarticleforfree.cfm?doi=AN9113600503 (pdf file)

Resources (** are especially good to start with)

Castor Oil

** How are castor oil, castrate, Castor & Pollux and the Canadian beaver related as words? Bill Casselman’s Canadian Word of the Day http://www.billcasselman.com/cwod_archive/beaver_castor_two.htm

The Castor Oil Resource http://www.castoroil.in This is a comprehensive portal.

Castor Oil [JAN] http://chem2.sis.nlm.nih.gov/chemidplus/

CASTOR OIL CASRN: 8001-79-4 http://toxnet.nlm.nih.gov

Chemical Name: Ricinus oil (Castor oil) CAS Registry Number: 008001-79-4 Synonyms: Vegetable oil; Ricinus oil; Castor oil (Ricinus communis L.); Castor oil

Integrated Taxonomic Information System (ITIS) Canada, Taxon based biological information system

Canadian Poisonous Plants Information System

Ricin http://www.bt.cdc.gov/agent/ricin/facts.asp

Fujitsu Develops New Bio-Based Polymer from Castor Oil
New material offers superior flexibility, has potential for use in manufacturing of small components in Fujitsu products […] [plastics]



** Surfactants: the ubiquitous amphiphiles, Chemistry World, 2003 July, Royal Society of Chemistry (retrieved December 16, 2007)
This article also includes a description of How surfactants work and I think provides a key to why castor oil soap for Dettol / Lysol, micelles.

Synthetic Detergents: Introduction to Detergent Chemistry
“As a matter of fact, soap became a detergent in 1907 when a German company … in the form of a sulfated castor oil, which was used in the textile industry. […]”



Germicidal and Insecticidal Values of Different Soaps. H. C. Hamilton. J. Ind. and Eng. Chem., 1911, 3, Associated Active Agents. 582-584. cited in 1911 Royal Society of Chemistry list of abstracts for castor oil soap. [retrieved 2007 December 13
http://www.rsc.org/delivery/_articlelinking/displayarticleforfree.cfm?doi=AN9113600503 (pdf file)]

LEGAL NOTES. 691. RE: adulteration of Lysol, 1934. Analyst 59, 691 – 694, DOI: 10.1039/AN9345900691 [retrieved 2007 December 13
http://www.rsc.org/delivery/_ArticleLinking/DisplayArticleForFree.cfm?doi=AN9345900691 (pdf file)]

The Handbook of Soap Manufacture [The Project Gutenberg eBook]
“Castor oil is abnormal in only undergoing about 20 per cent. hydrolysis, …. This name is applied to a soap solution of cresol, “Lysol Soap” being simply […]”

Elements of Chemistry: For the Use of Colleges, Academies, and Schools. Victor Regnault. 1853 – Translated by Thomas Forrest Betton. Clark & Hesser. Original from the University of Michigan Digitized Feb 17, 2006)
“By decomposing, by an acid, soap made with castor-oil, an oil separates, which partially coagulates at the ordinary temperature. […]”

Aids to Forensic Medicine W. G. Aitchison Robertson. 1922. 19th edition. BAILLIERE, TINDALL AND COX [The Project Gutenberg EBook]
“=Lysol= is a compound of cresol and linseed-oil soap, and is much less toxic…. A dose of castor-oil would be useful. […]” retrieved 2007 December 15

    [Listerine (1879) is a brand name mouthwash based on Dr Lister’s reputation but otherwise is no way related. http://en.wikipedia.org/wiki/Joseph_Lister%2C_1st_Baron_Lister

    There are two disinfectants in Listerine, alcohol and cinnamon. This is why Listerine and similar mouthwashes are effective against “bad breath germs” but also the bacteria causing cavities (caries). Alcohol we’ve discussed before.

    The disinfection power of cinnamon can be demonstrated by making bread for cinnamon toast. Prior to bread machines, cinnamon bread was a layer of cinnamon sugar butter and raisins rolled up in the dough and not mixed in the dough ingredients. I like cinnamon toast and figured I could make a cinnamony loaf in my bread machine. I added several teaspoons to the dry ingredients and pushed the button. The result? A blob of cooked stuff in the bottom of the bread pan. The cinnamon had killed the yeast.

    Some readers have searched for whether Clorox or bleach can be used as a mouthwash. It cannot and neither can Lysol ® or Dettol ®. They are simply too powerful and by stripping the protective skin layer in your mouth they may increase infection.]


Lysol Dettol chemistry

** Dr Mike Thompson, Winchester College, UK, Molecule of the Month description and illustrations, mentioned in the earlier post, is an excellent beginning.


Whats up with Lysol […]

or use the Australian website, http://www.rb-msds.com.au/
MSDS Dettol Liquid (Classic) (pdf file)

MSDS Lysol® Brand I.C. Quaternary Disinfectant Cleaner (Concentrate) note this is not brown bottle Lysol but the EPA approved disinfectant (pdf file)

Dettol Lysol toxicity

see also the Government of India’s listing, “13.Disinfectants & Antiseptics”

Don’t forget the recent Dettol Man or Lysol: too much of a good sanitizer can kill

* CRESOL Many attempted and successful suicides resulted from the ingestion of Lysol Disinfectant, which was introduced in 1860. It originally […] NIOSH Criteria for a Recommended Standard: Occupational Exposure to Cresol. February 1978,

retrieved 2007 December 13

** Household Products Database (National Library of Medicine, USA) http://householdproducts.nlm.nih.gov

Chemical Name: Pine oil CAS Registry Number: 008002-09-3 Synonyms: Pine oil; Oils, pine

Lysol contains phenol (40-55%) cresol (3%) and water (the rest) It does not contain o-phenol phenol. For those of you unfamiliar with Cresol I gather that it is a fraction of coal tar, and is a phenolic type product…. It does look to me and the technical chemist whom I obtained this information from as though there may well be differences between the product we know as “Lysol” here in Europe and the one known to you and produced by Reckit and Coleman Inc in the States.

from 1998 Conservation Distribution List-serv Conservation DistList Instance 12:46, Distributed: Monday, November 23, 1998, retrieved December 2007. Message Id: cdl-12-46-005

See also the entry on its history “Lysol [with or without (R)] has been around for a very long time and the formulation has changed many times […]” Conservation DistList Instance 12:46 Distributed: Monday, November 23, 1998 Message Id: cdl-12-46-004

lysol (cresol & soap solution) from the missing epa.gov page,
Agent Name LYSOL
CAS # 12772-68-8
RN or Registration Number, 12772-68-8
RTECS # OL5975000
Agent Code 43315
Systematic Source Name: CAS-9CI
Classification: Chemical
Molecular Formula: Unspecified
See NIH NLM chemical database here– Lysol RN: 12772-68-8

from R-B
MSDS# Not available.
Validation Date 4/5/2005
Dilutable liquid cleaner / deodorizer.
Product Identifier- Not available. [used if registered with EPA]
Item Number 353773
Formula Number 269-005
UPC Number 19200-02201 (12 oz.)
Name, CAS #, % by Weight
1) Ethanol, 64-17-5, 1-2%
2) Isopropyl Alcohol, 67-63-0, 1-2%
3) Xylenols, 1300-71-6, 1.5%
4) O-Benzyl-P-Chlorophenol, 120-32-1, 5-6%

MeSH Supplementary Concept Data 2008 (The Medical Subject Headings comprise the National Library of Medicine’s controlled vocabulary used for indexing articles, for cataloging books and other […] http://www.nlm.nih.gov/mesh/
Name of Substance Lysol
Record Type C
Registry Number 12772-68-8
Heading Mapped to *Cresols
Source, Bull Inst Marit Trop Med Gdynia 1983;34(3-4):205
Frequency 16
Date of Entry, 19850820
Revision Date, 19971118
Unique ID, C045926

Dettol (Canada) 2007
Name, CAS #, % by Weight
1) Pine Oil, 8002-09-3, 5-10%
2) Isopropyl Alcohol, 67-63-0, 10-20%
3) Chloroxylenol (4-Chloro-35-Xylenol), 88-04-0, 1-5%
other ingredients 65-84%

Dettol classic (from http://www.rb-msds.com.au/)
Name, CAS #, % by Weight
Chloroxylenol (4-Chloro-35-Xylenol), 88-04-0, 4.8% (%w/v)
Pine oil, 8002-09-3, <10%
Isopropyl Alcohol, 67-63-0, 10-30%
other ingredients, 55-75%
Dettol classic ingredients photoclick to enlarge

2008 MeSH (USA)
MeSH Supplementary Concept Data
Name of Substance chloroxylenol
Record Type C
Registry Number 88-04-0
Related Number 54983-54-9 (Na salt)
Related Number 58962-45-1 (K salt)
Entry Term 2-chloro-5-hydroxy-1,3-dimethylbenzene
Entry Term 3,5-dimethyl-4-chlorophenol
Entry Term Dettol
Entry Term Ice-O-Derm
Entry Term Micro-Guard
Entry Term PCMX
Entry Term Reckitt & Colman brand of chloroxylenol
Entry Term Reckitt Benckiser brand of chloroxylenol
Entry Term Reckitt brand of chloroxylenol
Entry Term Sween Prep
Entry Term Sween brand 1 of chloroxylenol
Entry Term Sween brand 2 of chloroxylenol
Entry Term Wampole brand of chloroxylenol
Entry Term chloroxylenol, potassium salt
Entry Term chloroxylenol, sodium salt
Entry Term p-chloro-m-xylenol
Entry Term parachlorometaxylenol
Heading Mapped to *Xylenes
Previous Indexing PHENOLS (70-82)
Source Br Med J 6117(1):890;1978
Source Contact Dermatitis 1(4):211;1975
Source J Appl Bacteriol 43:253;1977
Source J Hyg (Camb) 76(1):11;1976
Source J Pharm Sci 67(11):1627;1978
Source Med Sci Law 16(3):180;1976
Source Microbios 16(64):133;1976
Source Postgrad Med J 53(618):229;1977
Pharm. Action Anti-Infective Agents, Local
Pharm. Action Disinfectants
Pharm. Action Schistosomicides
Frequency 74
Note topical antiseptic; RN given refers to parent cpd; structure
Date of Entry 19700101
Revision Date 20041221
Unique ID C007027

2007-12-22 addendum
Lysol description, early 20th C
A Handbook of local therapeutics By Harrison Allen Published 1893. P. Blakiston

The Germans had an advanced coal-tar industry.
1916 text, Lysol taken from germany
Coal-tar and Ammonia By Georg Lunge Published 1916. D. Van Nostrand. Original from the University of California. v. 3 Digitized Sep 26, 2007

1908 Lysol description
A Text-book of materia medica, therapeutics and pharmacology By George Frank Butler Published 1908. Saunders.

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