What percentage of chlorhexidine (CHG) gluconate should be in a hand sanitizer?

Optimal Chlorhexidine Concentration in Hand Sanitizers

For hand sanitizers, chlorhexidine gluconate should be present at 0.5% concentration when combined with alcohol (60-95%), which provides optimal antimicrobial efficacy while minimizing skin irritation. 1, 2

Alcohol as Primary Active Ingredient

• Alcohol-based hand sanitizers should contain 60%-95% alcohol (ethanol or isopropanol) as the primary active ingredient for optimal antimicrobial efficacy 1, 2
• Higher alcohol concentrations (>95%) are less effective because proteins are not denatured easily in the absence of water 1
• Ethanol 60%-95% is classified by the FDA as a Category I agent (generally safe and effective) for use in antiseptic handwash products 2
• 60% isopropanol has been adopted in Europe as the reference standard for alcohol-based hand rubs 2

Chlorhexidine as Supplementary Agent

• When chlorhexidine is added to alcohol-based solutions, 0.5% concentration is optimal for providing persistent antimicrobial activity without excessive skin irritation 1
• Alcohol-based preparations containing 0.5% chlorhexidine gluconate demonstrate persistent activity that equals or exceeds that of chlorhexidine gluconate-containing detergents 1
• Higher concentrations of chlorhexidine (4%) are primarily used for surgical hand preparation and skin antisepsis, not routine hand sanitizers 3
• Products containing 4% chlorhexidine are more likely to cause dermatitis when used frequently compared to lower concentrations 3

Antimicrobial Efficacy

• Alcohols have excellent germicidal activity against gram-positive and gram-negative bacteria, multidrug-resistant pathogens, Mycobacterium tuberculosis, and various fungi 1, 2
• Adding 0.5% chlorhexidine to alcohol solutions provides residual antimicrobial activity that pure alcohol formulations lack 1
• The combination of 70% isopropanol with 0.5% chlorhexidine gluconate has demonstrated a 6.0 log reduction of HIV in 15 seconds, showing excellent virucidal activity 1
• Chlorhexidine has substantial residual antimicrobial activity on the skin, making it valuable for sustained protection beyond the immediate use of the sanitizer 3

Application Considerations

• The volume of product applied is critical - insufficient volume results in inadequate antimicrobial activity 2
• For routine hand hygiene, alcohol-based hand sanitizers should be applied to all surfaces of the hands and rubbed until completely dry (approximately 30 seconds) 2
• Alcohol-based sanitizers should not be applied to wet hands as this dilutes the concentration and reduces effectiveness 2
• Alcohol can prevent the transfer of healthcare-associated pathogens more effectively than handwashing with plain soap and water when hands are heavily contaminated 2

Safety Considerations

• Care must be taken to avoid contact with eyes when using preparations with chlorhexidine, as it can cause conjunctivitis and corneal damage 3
• Contact dermatitis related to chlorhexidine is uncommon in healthcare workers, with an incidence of approximately 2.5-5.4% in atopic patients 4
• Adding 1%-3% glycerol or other skin-conditioning agents can reduce the drying effect of alcohol on skin, improving compliance 2
• Alcohol-based sanitizers should never be ingested, as this can lead to serious health consequences including methanol poisoning if the product is contaminated 5, 6

Quality Control Considerations

• Regulatory bodies should ensure that hand sanitizers maintain proper concentrations of active ingredients throughout their shelf life 6
• The pandemic has led to increased prevalence of falsified alcohol-based hand sanitizers, including products with alcohol concentration less than 60%, highlighting the importance of purchasing from reputable sources 6