It is not uncommon to see acid still being used to clean washrooms or oil stained surfaces at homes, hospitals, industries and hotels in India, oblivious of its ill-effects on environment and the future of mankind itself. Both eco-friendly and hazardous cleaning chemicals are available by the score in the market, and this has necessitated the need for proper understanding of their composition for suitable applications. “Cleaning chemicals are used for housekeeping, personal hygiene, laundry, fabric, industry, kitchen and other areas,” explains Abhay Desai, Director-Marketing, JohnsonDiversey India.
These formulated cleaning agents are broadly available in two categories: consumer products and institutional products. Even though a consumer product is much simpler to use, its application is limited. Institutional product has a much wider application dealing with specific needs in specific areas of specific surfaces.
“The formulated chemicals for institutions are concentrates or super concentrates where the costing/use fundamental come into play, wherein the cost per use is the basis of cost application for an institution. With consumer products, the costing/use calculations do not come into picture at all. The consumer merely uses the recommended amount of, say a detergent, for washing certain amount clothes. The consumer does not calculate per spoon/number of clothes costing. Similarly, fabric washing for consumers is all about a single detergent while for institutions linens have to be treated differently. The institutional market in itself has specific needs. A typical laundry, for example, in a five-star hotel would wash at least 2.5 to 3 tonnes of linens in a single day consisting of bed sheets, towels, chef coats, tablecloths and other cloths. Each of these would have a different soil to be treated. A towel would have hair and oil stains or F&B linen would have ketchup, spices and oil stains. Hence, one single detergent and a single-wash programme would be ineffective to treat these stains. Different linens have to be treated differently with different chemicals in different proportions.
“For consumers, again there are no benchmarks on the levels of cleaning, while for institutions, the cleaning effectiveness is measured. For example, in a hotel the brightness of linen, the rewash levels and fabric discards in a year are recorded. Similarly, cleaning agents in combination or in specific formulations are used for cleaning in all other applications,” adds Abhay Desai.
Cleaning agents, particularly chemicals, are intended to clean, disinfect and sanitise. Ingredients of all cleaning chemicals have necessary substances, including surfactants, solvents, phosphates, EDTA (ethylene-diamine-tetra-acetic acid) and degreasers.
Detergents, one of the most common chemicals used for cleaning, remove soil from a surface through a chemical action. These detergents dissolve solid soils and hold them in suspension away from the surface and thus allow them to be removed from that surface. Housekeeping detergents are mostly derived from basic minerals, primarily sulfonated hydrocarbons. “The tartness of the detergent depends on its pH level. Detergents with neutral pH has neither acidic nor alkaline compound. The degree of acidity or alkalinity is indicated in the pH scale which runs from 0-14. The pH from 0-6 on the scale indicates acidity, 8-14 indicates alkalinity and 7 indicates neutral compound,” says Dr Richard Joseph, Advisor, Scheveran Laboratories.
Alkalies enhance the cleaning power of a synthetic detergent. Strong detergents are suitable for degreasing in industries or kitchens where there are a lot of oil or grease deposits and but are not recommended for certain floors of soft metals like aluminium or galvanised surfaces.
“The choice of a particular suitable formulated detergent depends upon the type of soiling, the surface to be cleaned, the time available for cleaning and specific requirements like grout cleaning & faucet cleaning,” adds Abhay Desai.
Detergents can be used in an industrial environment for various applications like floor scrubbing, degreasing or general cleaning works. Says V. Balathandayutham, Manager-Product Support, Roots Multiclean Ltd, “The main challenge in industries is to tackle the grit and grease. Generally, the built up grease is tracked throughout the premises during traffic. The detergent helps to remove the embedded dirt and grease effectively. When the build up is low both scrubbing and vacuuming can be done with a machine at one stretch. However, when the build up is comparatively higher, the degreaser emulsifies dirt slowly and then the sides are extracted. User friendly, economical degreasers and dirt removers are used for various applications like machine scrubbing, manual scrubbing and higher dirt removal.
“Detergents are used depending upon the type of industry and various floor types like tiles, coating, synthetic and rubber. A general purpose neutral detergent comes handy for wet mopping or for wet cleaning of office furniture and equipment. These detergents have high viscosity and excellent cleaning performance even with less quantity.”
The different levels/degrees of cleaning are sterilisation, disinfection and sanitisation. The process of sterilisation, mostly applicable in hospitals, ensures that the surface is 100% free from contamination. This cleaning process is specialised and has a different set of cleaning agents (which is not discussed in this article).
Disinfection chemicals destroy pathogenic microorganism on inanimate surface. Washroom specific chemicals “discourage the development of resistant types of pathogenic microorganisms building up in a toilet”, says Dr Joseph.
Used closely with disinfectants are sanitisers which remove contamination only to a certain extent, but makes the surface clean enough to protect health in general. “Like a hospital, that has marble flooring in the lobby, could require not just cleaning chemicals to keep it clean and nice but a sanitiser to decontaminate,” says Abhay. Sanitisers could be specially formulated chemicals or may be disinfectants that have been diluted to serve as sanitisers.
All the above chemicals could be used in combination to achieve the desired result of cleanness. A combination of detergents and disinfectants helps treat soil and decontaminate the surface. Disinfectant alone when used on a soiled surface in a toilet will not be effective. The soil protects the bacteria from germicidal action of the disinfectant. Thus, the choice of chemicals and its combination depend on the area of its application.
Chemicals when applied to a surface have to be in the right proportion to achieve the desired result.
A US study has warned not to over-dilute cleaning chemicals amid fears that this could boost resistance in bacteria. The study found that such bugs that survived disinfectants could be harder to kill. They evolve new defences which allow them to ‘pump’ cleaning chemicals out of their system. Experts have advised that cleaning guidance is followed closely.
Disinfectants are not just hospital-specific, as hotels and restaurants too provide an environment for breeding and transmission of diseases.
According to the Centre for Disease Control, USA, 77% of food borne illness originates in commercial food service establishments. The most common areas that need disinfectants in a hotel include the air conditioning system, bathroom fixtures, partitions, soap & towel dispensers, bathroom floors and fixtures, toilets, urinals, area around urinals, levers to flush toilets, telephones and drains.
Dry solvents are liquid chemicals that do not mix easily with or contain water. These chemicals are hydro-phobic, or have “water-fearing” molecules, which can be very effective at dissolving greasy, oily soils.
Odourless mineral spirits (OMS) are typically used for dry cleaning furniture, and also used as the carrier for other products, such as “dry” carpet protectors. OMS are used to carry fluorochemical protectors in applications where excess water is undesirable, such as in upholstery care.
To this day, perchloroethylene, or “perc,” is still the most common dry cleaning solvent due to its stability, relatively low flammability, and gentleness on textiles.
Another dry solvent that is found in dry-cleaning products for spot and stain removal is Benzin, also known as petroleum ether or “naphtha.” Naphtha, while very effective at dissolving hydrophobic soils without bleeding carpet dyes, can be particularly nasty to handle, and should always be used with great care. Citrus solvents are very popular today and considered much safer to use.
The main component of all of these so-called “oxygen bleaches” is hydrogen peroxide. Peroxide bleach is used by the professional carpet cleaner today to boost the performance of many cleaning chemicals. A small amount of powder (the chemical is sodium percarbonate) is added to the cleaner, and the results can be amazing. Sodium percarbonate itself is not peroxide. When the chemical is added to water, peroxide is generated. However, the peroxide is not stable in the cleaning solution and will lose its effectiveness if not used right away.
The chemical opposite of an oxidizer like peroxide is a reducing agent. Reducing agents are compounds that donate negatively charged electrons to other compounds, chemically changing them. Perhaps the most commonly used reducing agent in cleaning is sodium metabisulfite, a weak reducer that is used on coffee and red stains. Caffeine and red food dye are only coloured in their oxidized state, so by using a reducing agent, those chemicals are converted into products that are not coloured, thereby eliminating stains. Red dye is tougher to reduce than caffeine, which is why heat is recommended when removing red stains.
All purpose cleaning solution
There are many all-purpose cleaning solutions today in the market which provide a combination of chemicals suitable for most surfaces. There is an increase in demand for such products as it does away with the challenge of proportional mixing which is often handled by the cleaner who may not be from a sound educational background. A cleaner’s knowledge is limited to the training he receives. Most all-purpose cleaning solutions are pH neutral and safe for most surfaces that are cleaned with water-based products. These cleaning solutions do not leave a haze.