Are Alcohol-free Hand Sanitizers Effective?

alcohol-free hand sanitizers

With the current Covid-19 outbreak, it is difficult to get hold of any hand sanitizers and therefore, having an alcohol-free hand sanitizer is probably better than none at all. 

Alcohol-free hand sanitizers are effective in reducing microbes. What are some of the active ingredients suitable for your hand sanitizers? Some regularly used disinfectants are Benzalkonium Chloride (BKC), Didecyl Dimethyl Ammonium Chloride (DDAC), Dioctyl Dimethyl Ammonium Chloride (DODAC) and Chloroxylenol (PCMX).

Quaternary Ammonium Compounds (QAC)

In general, QACs are active towards vegetative bacteria, enveloped viruses and most yeast and moulds. However, they are less effective against spores, Mycobacteria, non-enveloped viruses and some gram negatives. They are membrane active agents and have a similar mechanism to alcohols where they disrupt the lipid structure of the viral envelope.

BKC

BKC is a common alternative to alcohols in alcohol-free hand sanitizers. It offers strong detergency and rapid, safe, powerful antimicrobial activity at low ppm. BKC based disinfectants are non-toxic, non-tainting, non-corrosive, non-staining and odour-free at use dilutions.

DDAC

DDAC are used in many biocidal applications. It can reduce microbes; however, they are less effective in killing germs compared to alcohols and require a longer contact time to show significant effect. Hence, they are typically used as disinfectants in surface disinfecting products.

DODAC

Similar to DDAC, DODAC is a broad-spectrum disinfectant that requires longer contact time to kill germs. It has been used in human and instrument sensitization and industrial applications. Furthermore, it can be used as disinfectant cleaner for linen, recommended for use in hospitals, hotels and industries.

Chloroxylenol (PCMX)

PCMX is another alternative. PCMX is a halogen-substituted phenolic compound that is widely used as preservatives in cosmetics and active agents in anti-microbial soaps. Similar to QACs, PCMX is also poorer than alcohols and is effective in reducing microbes to a certain extent.

Characteristics of PCMX
INCI Name & CAS No. Product Characteristics Quaternary Ammonium Compounds (QAC)
4-Chloro-3, 5-m-Xylenol; PCMX High efficiency, broad spectrum, gram +/- Mildew, low-toxic antiseptic, approved by FDA Household and personal care products, liquid detergent (0.5% – 1%), antibacterial handling detergent (1%), disinfectant (4.5% – 5%)

Comparison Between Commonly Used Disinfectants

Halophenols Quaternary Ammonium Compounds (QAC)
Chemical Name Chloroxylenol (PCMX) Benzalkonium Chloride (BKC) Didecyl Dimethyl Ammonium Chloride (DDAC) Dioctyl Dimethyl Ammonium Chloride (DODAC)
 Mechanism  Effective against viruses but mechanism is less studied Disrupt lipid structure of viral envelope
 Suitable For Hand sanitizers and surface disinfectants Surface disinfectants
Recommended Dosage 4.00% 0.16% 0.15% 0.15%
Compatibility Issues  Neutralised by non-ionic surfactants Incompatible with anionic surfactants

More Information to Help You Select a Suitable Active Ingredient

Evolution of QACs
Generation Cell Hard Water Tolerance Fungal Activity
Alkyl Dimethyl Benzyl Ammonium Chloride 1 Lowest
Alkyl Dimethyl Ethyl Benzyl Ammonium Chloride 2
Alkyl Dimethyl Ethyl Benzyl Ammonium Chloride / Alkyl Dimethyl Benzyl Ammonium Chloride 3 Better
Alkyl Dimethyl Ammonium Chloride 4 Highest Best Best
Dialkyl Dimethyl Ammonium Chloride / Alkyl Dimethyl Ethyl Benzyl Ammonium Chloride 5 High Better Better
Antimicrobial activity and summary of antiseptics
WHO guidelines on hand hygiene in health care. (2011, August 5). Retrieved from https://www.who.int/gpsc/5may/tools/9789241597906/en/
Summary of disinfectants
WHO guidelines on hand hygiene in health care. (2011, August 5). Retrieved from https://www.who.int/gpsc/5may/tools/9789241597906/en/

Formulation Guide: Alcohol-free Hand Sanitizers

Phase Material INCI Name Supplier % W/W % W/W
A Propylene Glycol Propylene Glycol 5.00 5.00
Glycerin* Glycerin 5.00 5.00
Deionized Water Water q.s. to 100.00 q.s. to 100.00
B K-CARE BKC80 Benzalkonium Chloride Maha Chemicals 0.1625
K-BIO PCMX 4-Chloro-3, 5-Dimethylphenol Maha Chemicals 4.00
C Aloe Vera Extract BG Aloe Barbadensis Extract, Butylene Glycol TEN 1.00 1.00
Chamomile Extract BG Chamomille Recutita (matricaria) Flower Extract, Butylene Glycol TEN 1.00 1.00
D AMP 95 Aminomethyl Propanol Angus q.s. q.s.

Procedures

  1. Predisperse phase A in room temperature
  2. Add phase B and phase C while mixing
  3. Adjust pH to 6 – 7.5 with AMP 95 if necessary
  4. * Glycerin can be replaced by Aloe Vera Extract

End Product Appearance

Appearance Clear – Slightly hazy liquid
pH 7.0-7.5

Formulation Guide: Hard Surface Sanitizers

Phase Material INCI Name Supplier % W/W % W/W % W/W % W/W
A Deionized Water Water q.s. to 100.00 q.s. to 100.00 q.s. to 100.00 q.s. to 100.00
B K-CARE BKC80 Benzalkonium Chloride Maha Chemicals 3.00
K-CARE DDAC80 Didecyldimethylammonium Chloride Maha Chemicals 0.15
K-CARE DODAC Dioctyldimethylammonium Chloride Maha Chemicals 0.15
C GLDA Tetrasodium Glutamate Diacetate 0.20 0.20 0.20 0.20
  1. Predisperse phase A in room temperature
  2. Add phase B and phase C while mixing
  3. Adjust pH to 6 – 7.5 with AMP 95 if necessary
  4. * Glycerin can be replaced by Aloe Vera Extract

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