Castor oil soap and Dettol Lysol

My apologies for not returning sooner to Mr. M. Manogaran’s interesting query left as a comment at
http://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.

Skip to
• General Notes
• Lysol / Dettol
• Castor oil soap
• Resources (** are especially good to start with)
• Castor oil
• Soap
• Historical
• Lysol Dettol chemistry

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