Hand Sanitizer

Caframo Tips for Alcohol-Based Hand Sanitizer

Published in Dissolving, Mixing

Woman's hands under running water at sinkIn these extraordinary times of COVID-19, both people and organizations are rapidly adapting to critical needs as they emerge.  One product that has risen in priority is alcohol-based hand sanitizer.  It is important to note that both the CDC and Health Canada, amongst other authorities, recommend washing hands with soap and water as the best method for hand hygiene, including the COVID-19 virus.  However, when water and soap are not available, an alcohol-based hand sanitizer can be helpful to minimizing spread of microbes.

With a shortage of hand sanitizer available, both people at home and manufacturing sites are investigating how to make their own alcohol-based sanitizer.  For healthcare settings, alcohol-based sanitizers with greater than 60% ethanol or 70% isopropyl alcohol are recommended.  The basic ingredients required include alcohol, a skin conditioning agent, and water.  A commonly referred formula is published by the WHO, which uses ethanol or isopropyl alcohol, glycerol, hydrogen peroxide, and water.  A popular DIY formulation is a 3:1 alcohol:aloe vera gel.  Regardless of formula used, accurate measurement is key to ensure the minimum concentration of alcohol is present to be effective.  Also critical is that both alcohols used in these formulations are highly flammable.  The mixing environment and equipment used in the vicinity of these materials should follow safety guidelines and legal requirements for your jurisdiction.

More formal manufacturing formulations will often include a thickening agent, but this is not required.  For formulations adding thickeners a wide range of options are available, including various cellulose derivatives, carbomers, and gums.  A variety of alcohol-based hand sanitizer formulations are available from raw material suppliers for cosmetics and pharmaceutical products, and other resources within these industries.  It is important to understand the properties of the thickener being used.  An example is carbomers which are highly specialized for their applications – be sure to check it will thicken in the high alcohol concentrations required for the final formulation.  Carboxymethyl cellulose (CMC) and hydroxyethylcellulose (HEC) are insoluble in organic solvents such as ethanol, but hydroxypropyl methylcellulose (HPMC) is commonly used in alcohol solutions of 62-70%.  As well, carbomers and cellulose thickeners are water soluble, so there is risk of agglomerating or lumping when first wetted.  There are grades of these materials made specifically to disperse and delay hydration to avoid this.  It is also important to know the shear tolerance of these thickeners once they are activated.  A discussion with your raw material supplier can help direct you to the product that best suits your formulation requirements.

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When making alcohol-based hand sanitizers as a gel, a Caframo overhead stirrer can be valuable to increase productivity and ensure quality in production.  Caframo overhead stirrers such as the Ultra Torque 1850 and Universal 3030 have proven performance in premixes of gums and other thickeners, having the torque required to maintain flow as the particles hydrate and the gel thickens.  With accurate speed control, creating a stable vortex is helpful for wetting the thickener and avoiding agglomerates.  The ability to change impellers as required provides the flexibility to use a typical prop for low shear yet effective flow, but adjust to high shear mixing with a crossed blade or dispersion blade as needed.   Caframo overhead stirrers have brushless DC motors which are sparkless, which allows small scale formulation or production with alcohols with the proper environmental controls, such as a fume hood, if permitted by local regulations.

Caframo qualifies as an essential service as a manufacturer, so we are continuing production and maintaining our commitment to be in stock. Contact us today as you have in the past, to see how we can support providing hand sanitizer to meet this most urgent need.

1540 Crossover Mixer

1540

BDC1850, Ultra Torque

1850

BDC2010

2010

References:

Ashland (n.d.)  Natrosol™ hydroxyethylcellulose.  Retrieved April 2020, from https://www.ashland.com/industries/energy/oil-and-gas/natrosol-hydroxyethylcellulose

Botaneco (n.d.)  Natural Hand Sanitizer Formulation #BC-37-18-B.  Retrieved April 2020, from https://www.botaneco.com/upload/media_element/attachments/64/Natural%20Hand%20Sanitizer%20(BC-37-18-B).pdf

Centers for Disease Control and Prevention (2020 Mar 14).  CDC Statement for Healthcare Personnel on Hand Hygiene during the Response to the International Emergence of COVID-19.  Retrieved April 2020, from https://www.cdc.gov/coronavirus/2019-ncov/infection-control/hcp-hand-sanitizer.html

Centers for Disease Control and Prevention (n.d.).  Handwashing and Hand Sanitizer Use: at Home, at Play, and Out and About.  Retrieved April 2020, from https://www.cdc.gov/handwashing/pdf/hand-sanitizer-factsheet.pdf

Centers for Disease Control and Prevention (2020 Mar 03).  Show Me the Science – When & How to Use Hand Sanitizer in Community Settings.  Retrieved April 2020, from https://www.cdc.gov/handwashing/show-me-the-science-hand-sanitizer.html

Centers for Disease Control and Prevention (2020 Apr 02).  When and How to Wash Your Hands.  Retrieved April 2020, from https://www.cdc.gov/handwashing/when-how-handwashing.html

ChemicalBook (2017)  Sodium carboxymethyl cellulose. Retrieved April 2020, from https://www.chemicalbook.com/ChemicalProductProperty_EN_CB5209844.htm

Chemists Corner (2020 Mar)  Hand Sanitizer Sodium Carbomer issue [Cosmetic Science Talk discussion forum].  Retrieved April 2020, from https://chemistscorner.com/cosmeticsciencetalk/discussion/7266/hand-sanitizer-sodium-carbomer-issue

Government of Canada (2020 Mar 19).  Hand Hygiene.  Retrieved April 2020, from https://www.canada.ca/en/public-health/services/healthy-living/hand-hygiene.html

Hernandez, D. (2020 Mar 15)  What to Know Before Making Your Own DIY Sanitizer.  Retrieved April 2020, from https://www.popularmechanics.com/science/health/a31265105/coronavirus-diy-hand-sanitizer/

Institute of Personal Care Science (2020 Mar 9)  Sanitizing hand gel – hospital grade.  Retrieved April 2020, from https://www.youtube.com/watch?v=PMBqueQebIE

Lindberg, S.  (n.d.)  How to Make Your Own Hand Sanitizer.  Retrieved April 2020, from https://www.healthline.com/health/how-to-make-hand-sanitizer

Lotioncrafter (n.d.)  Hydroxyethylcellulose (HEC).  Retrieved April 2020, from https://lotioncrafter.com/products/hydroxyethylcellulose-hec-1

Lubrizol Corporation (2012)  TDS-237: “Neutralizing Carbopol® and Pemulen™ Polymers in Aqueous and Hydroalcoholic Systems”.

Lubrizol Corporation (2012)  TDS-255: “Formulating Hand Sanitizing Gels with Carbopol® Polymers”.

Nikolopoulos, G. (n.d.)  Carbopol® (Carbomer).  Retrieved April 2020, from https://www.admix.com/carbopol.

Qianhao Chemical (2019)  Common questions about cellulose products and their applications Part 2: Application of cellulose in rinse-off formula.  Retrieved April 2020, from https://www.qianhaochem.com/news/common-questions-about-cellulose-products-and-their-applications-part-2-application-of-cellulose-in-rinse-off-formula/

Redmond, M.J., and Neuser J.H. (2015 Mar)  Topical Sanitizer that Includes Avenanthramides.  [Patent Application]  Retrieved April 2020, from https://patents.justia.com/patent/20160279074

Seppic (n.d.)  Hydroalcoholic Gel: Regulation update.  Retrieved April 2020, from https://cdn.shopify.com/s/files/1/0026/8317/5001/files/SEPPIC_Hand_Sanitizer_Info.pdf?v=1585771504

World Health Organization (2010 Apr) Guide to Local Production: WHO-recommended Handrub Formulations.  Retrieved April 2020, from https://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf

World Health Organization (2009) WHO-recommended handrub formulations.  WHO Guidelines on Hand Hygiene in Health Care: First Global Patient Safety Challenge Clean Care Is Safer Care.  Retrieved April 2020, from https://www.ncbi.nlm.nih.gov/books/NBK144054/