Dr Sanjay Bhattacharya, Consultant in Microbiology, Tata Medical Center, Kolkata

In a tour de force paper, Dr Sanjay Bhattacharya, Consultant in Microbiology, Tata Medical Center, Kolkata refers extensively to published protocols and indexed studies to summarise what India lacks in disinfectant use protocols, and suggests parameters by which a disinfectant may be assessed.

Defining terms

Disinfectants are chemicals which are used to kill or inhibit the growth of microorganisms such as viruses, bacteria, parasites and fungi. The term biocides is also used in some countries to refer to disinfectants and antiseptics collectively. When disinfectants are applicable to body surfaces, they are sometimes referred to as antiseptics. Although many brand names have been in use for a long time, little is known or understood by the lay population about specifics such as efficacy, safety or selection criteria of one disinfectant over other agents in the market.

Lack of regulation

In India, cleaning and disinfectant products are not regulated under a separate Chemical Regulatory framework. Disinfectant products in India are generally classified under the ‘drug’ category and require approval from the CDSCO. Disinfectants are permitted to be marketed in India after approval from CDSCO.

The 2022 National List of Essential Medicines has the following antiseptic and disinfectants: chlorhexidine 5%, ethyl alcohol 70%, hydrogen peroxide 6%, Gentian violet 0.2-2%, Povidone iodine 4-10%, glutaraldehyde, potassium permanganate (crystals for topical solution), cetrimide 20%, bleaching powder (concentration not less than 30% w/w of available chlorine).

Guidelines for the use of disinfectants in India do not appear to be comprehensive enough to include policies of use, manufacture, quality control and safety standards.

Considering the significant use and demand of disinfectant within India, it would be important to have a national disinfectant policy. This will provide guidance to the consumers, manufacturers and merchants of such products with up to date information about safety, efficacy, utility, and regulatory requirements associated with them.

Role in healthcare

In the healthcare sector, disinfectants have many applications which include water chlorination, aerial disinfection, surface disinfection, medical device disinfection, hand sanitisation, disinfection of skin before surgical procedures, spill management, laundry, kitchen, etc. It is important that disinfectants in healthcare and other industries are selected after careful consideration.

Choosing a disinfectant

The factors which should be taken into account before disinfectant selection include: microbiological efficacy of the disinfectant, material compatibility of the product against the surfaces on which it is to be applied, chemical compatibility (when chemicals are used in mixtures), safety, cost and availability. All the factors are important while performing an option appraisal of a disinfectant product.

Microbiological efficacy

The disinfectant ideally needs to be efficacious against a wide range of microbial agents so that it has bactericidal, virucidal, mycobactericidal, fungicidal and parasiticidal activity.

Safety

The MSDS (material safety data sheet) needs to be checked so that the potential side effects and adverse effects from chronic or acute exposure may be understood, assessed and protective measures and remedial measures put in place.

Surface compatibility

Material compatibility of disinfectants is also critical and this needs to be checked before the disinfectant is selected for application. Chemical compatibility databases are available from some web based resources but these need to be developed also by the government agencies to increase reliability and authenticity.

Cost and availability

These are important practical considerations. Unlike antimicrobial agents, disinfectants are used chronically over a prolonged period of time and not episodically. Therefore, long-term cost considerations and financial viability of using them over a protracted period of time is important. It is important that the product is available in the market so that access is not interrupted because of irregular manufacturer, irregular supplies or breakdown in the supply chain.

Resistance to disinfectants

Microbial resistance to biocides or disinfectants is not new. However, the community awareness about this problem is lacking. Unlike antimicrobial resistance (AMR), where systems have been developed over the years for detection, monitoring and research regarding the epidemiology, clinical and economic cost assessment of antibiotic-resistant bacteria, very few institutions and systems are available within India about disinfectant resistance research.

Judicious use

Disinfectants are not a substitute for cleaning, neither are they a substitute for sterilisation. The choice between cleaning, disinfection and sterilisation has to be based on Spaulding classification. For non-critical procedures involving contact with skin, only cleaning is sufficient in most cases; for semi-critical procedures involving contact with mucous membrane, disinfection is essential; whereas, for critical procedures which involves contact with sterile tissues and body cavities, sterilisation of medical devices is essential.

What does India need?

• A national policy and a guideline with regard to rational and judicious use of disinfectants
• Disinfectant efficacy and safety testing systems: research centers, quality control institutes
• Development of protocols and procedures (standard operating procedure and testing technology) for testing antimicrobial resistance to disinfectants
• Consumer information and public education with regard to safety and efficacy of disinfectants and their rational and judicious use
• A clear and transparent system with regard to disinfectant regulation, pricing and approval
• Development of material compatibility, chemical compatibility and safety database for disinfectants