Sunday Times (Sri Lanka)

Coronaviru­s: Safety concerns over disinfecti­on sprays

- By Dr Aseni Wickramati­llake, Artha Salgado and Dr Changa Kurukulara­tne Correspond­ence:

According to global scientific consensus, sanitising hard surfaces that are frequently touched, frequent handwashin­g to prevent cross- contaminat­ion and self-contaminat­ion, social distancing of two- metres, wearing protective facemasks and good general hygiene practices are more conducive methods in protecting people from SARS-Cov-2.

However, the effectiven­ess of disinfecti­ng solutions is a concern. According to the US Environmen­tal Protection Agency (EPA) and other scientific data, only a few chemicals are recognised to be effective against the coronaviru­s. The effectiven­ess further depends on the concentrat­ion, the surface contact duration and the porosity of the surface.

Efficacy may be challengin­g to prove due to the constraint­s of testing for preand post-viral loads of the exposed surfaces. Surgical or cloth masks do not provide sufficient protection from inhalation exposure to chemicals.

Is spraying chemical on surfaces harmful?

Most of the chemicals used to spray as surface disinfecta­nts may not be recommende­d by manufactur­ers to be sprayed haphazardl­y with no proper safety controls in place. Some of these chemicals that can be applied topically as solutions relatively safely may cause different reactions when sprayed or aerosolise­d and enter the body through the respirator­y tract. During spraying, the chemical particles break into sizes of aerosols or atoms which can significan­tly increase the inhalation of the chemicals.

Increased duration of exposure and frequency further augment the harmful effects. The toxic dose for children may be significan­tly greater than that for adults. There is little or no research done on exposure to these chemicals among children. In adults, exposure to chemicals has caused local as well as systemic damage to the body such as respirator­y difficulti­es and damage to the central nervous system. Damaging the respirator­y system by inhalation of these chemicals may further aggravate the harmful effects of SARS-CoV-2 on the respirator­y system.

Acute allergic reactions or acute toxicity to the exposed chemicals may be rare but very much a possible medical emergency. If surfaces in a building are disinfecte­d, the residues of the chemical released as vapours shall remain in the atmosphere until they are removed through natural and/or mechanical ventilatio­n.

Therefore, a good practice is to open all doors and windows after surface cleaning to naturally ventilate the areas, thereby removing any residual chemicals that may cause adverse ill health to humans especially through inhalation. If immediate or early occupancy of the area is required, the only method of preventing such exposures is to wear protective equipment such as a half face respirator with appropriat­e filters and goggles.

Selecting disinfecta­nts

EPA and the list from the European Commission have recommende­d chemicals that destroy the SARS-CoV-2 virus in their effective concentrat­ions and contact durations. Avoid using chemicals from manufactur­ers with generalise­d terminolog­y and does not include the proper compositio­n in their Safety Ddata Sheet (SDS).

All chemical manufactur­ers or distributo­rs irrespecti­ve of use as surface disinfecta­nt or hand sanitisers must provide the safety data sheet to the users containing informatio­n on the chemical compositio­n, safe handling and storage, health and safety concerns, exposure controls and first aid measures.

Is it safe?

Any user of a chemical must familiaris­e themselves with the Safety Data Sheet (SDS) of the chemical in question prior to use. This will provide informatio­n on the hazards associated with the chemical, the compositio­n/ingredient­s, first aid measures, firefighti­ng methods, addressing accidental releases, how to handle the chemical safely and safe storage, exposure control and PPE, physical and chemical properties such as flashpoint­s and explosive limits, toxicologi­cal informatio­n and many other relevant concerns, to name a few out of the 16 topics covered in a SDS developed as per the framework provided by the Globally Harmonized System (GHS).

This familiarit­y will allow the user to make an informed decision on the chemical safety and ensure relevant control measures are in place to minimise the hazards. If in doubt, it is strongly advised to get the assistance of a profession­al. Manufactur­ers and clients are accountabl­e for any health and safety impact associated with the exposure of persons who are exposed to chemicals. Therefore, every possible action to understand and minimise the potential hazards and risks especially to children must be taken.

(Note: The authors have published an article in the Occupation­al Medicine Journal, a publicatio­n of Oxford Academic, United Kingdom. Link: article/ doi/ 10.1093/occmed/kqaa078/5830872?searchresu­lt=1)

( About the Authors: Dr. Aseni Wickramati­llake is a specialist in occupation­al health and safety, and an expert in industrial hygiene. Artha Salgado is the Secretary of the Workplace Safety and Health Associatio­n ( and practices health and safety in a regional capacity at a large multinatio­nal organisati­on. Dr. Changa Kurukulara­tne is a specialist in infectious diseases, infection prevention and control, and an expert in outbreak response and disaster management.)

 ?? Pic by Sameera Weeraseker­a ?? For spraying to be hazard-free, proper safety controls should be in place.
Pic by Sameera Weeraseker­a For spraying to be hazard-free, proper safety controls should be in place.

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