CHAPTER 4.
CLEANING AGENTS
Cleaning is primarily the removal of dust and dirt. Dust to being composed of loose particles, is removed comparatively by the use of various types of equipments, dirt however, owing to this adherence to surfaces by means of grease or moisture, requires the use of cleaning agents in conjuration with the right equipment if it is to be removed efficiently.
Cleaning agents in general can be defined as natural or synthetic substances that are used to assist the cleaning process – that is, removal of dirt and grit and the maintenance of a clean appearance on the surface. The various kinds of cleaning agents used by the housekeeping department staff are depicted in Figure 7.8 .
| Cleaning Agents |
| Abrasives |
| Reagents |
| Organic solvents |
| Detergents |
| Water |
| Floor Strippers |
| Toilet cleaners |
| Deodorizers |
| Disinfectants & bleaches |
| Laundry aids |
| Glass cleaners |
| Floor sealers |
| Polishes |
| Carpet cleaners |
Fig. 7.8 Various types of cleaning agents
WATER : -
Referred to as the universal solvent, this is the prime agent in the cleaning process. However, though an excellent solvent, water alone is not a sufficiently effective cleanser to meet the standards most hotels require. Indeed, it does not even wet a surface properly, as its surface tension prevents it from spreading easily. For water to be effective in cleaning, it must be used in conjunction with other cleaning agents such as detergents, soaps and so on. From the perspective of cleaning, there are two types of water – hard water and soft water. Soft water is ideal for cleaning purposes and also to make up the proper dilutions of other cleaning agents.
Sources of water
Water is available in abundance in some parts of the country, but is scarce in others. Sources of water may be surface, sub-soil or deep soil.
Surface water- Obtained from streams, rivers and lakes, it may contain both organic and inorganic impurities in large amounts.
Sub-soil water- Coming from shallow wells and springs, it is not likely to be contaminated with suspended matter and organic impurities. However, some gases and mineral matter are generally dissolved in it.
Deep soil water- Deep soil water, pumped up from deep wells, has percolated through, much soil and rock to reach its resting depth. Therefore it has a very high content of minerals such as calcium, magnesium, iron, sulphur, phosphates and silica as well as dissolved gases such as nitrogen, carbon dioxide and oxygen. The mineral salts dissolved in this water results in its hardness and render it unsuitable for cleaning purpose.
These days most of the cities, towns and some villages have running water supplied by the public works department (PWD). This water is filtered and chlorinated before being piped.
Hard water and soft water
Water that contains more than 60 ppm (parts per million) of calcium and/or magnesium is called hard water. When the mineral content is in the range of 61-120 ppm, the water is said to be more moderately hard and if it exceeds 180 ppm, the water is considered very hard. When the level of dissolved calcium and/or magnesium is below 60 ppm, it is said to be soft water. However, water from all sources contains varying amounts of calcium and magnesium, usually in the form of bicarbonates, sulphates and chlorides. It is their relative proportions that determine how ‘hard’ the water is and in what way.
Temporary hardness- This is caused by bicarbonates of calcium and magnesium being dissolved in water. Temporary hardness is so called because it can be removed by simply heating the water to a temperature above 72o C.
Permanent hardness- This is caused by sulphates and chlorides of calcium and magnesium dissolved in water. It cannot be removed by boiling and requires chemical treatment to render the water ‘soft’.
Effects of hard water
Calcium and magnesium salts dissolved in water inhibit lather formation from soaps and detergents, so that much more detergent will have to be added to precipitate out the calcium and the magnesium before cleaning can occur. This process causes a lot of scum to be formed, which may further soil the surface, when hard water is used for laundering, for instance, it causes premature ageing of fabrics due to constant friction with the deposits from hard water. They also become coarse and uncomfortable to wear. Hard water also causes scale and fur to be deposited in boilers, pipes and various appliances. Iron and sulphur salts can cause discolouration. Sulphur also causes a rotten – egg odour. Dissolved phosphates, on the other hand, can actually enhance the cleaning power of some detergents.
Methods of softening water
Water which has hardness greater than 50 ppm needs to be softened. Temporary hardness can be removed by boiling (or heating above 72oC). In the reaction that takes place at these temperatures, dissolved bicarbonates decompose with the liberation of carbon dioxide and the carbonates precipitate out as scum or fur these should be removed by filtration before using the water for cleaning.
In the case of magnesium bicarbonates, the resultant carbonate further decomposes into magnesium hydroxide
The most practical way of removing hardness , however, is to treat it chemically. This is done in one of the following ways :
Alkali method - The alkali calcium hydroxide is used to remove the hardness from water in this method.
Lime soda method – In this method, sodium carbonate and calcium hydroxide are both used to remove the hardness.
Addition of sequestering/chelating agents – Sequestering agents are organic or inorganic compounds that react with metallic ions and form a complex. These metallic ions will still be present in the water, but will be unable to react with soaps or detergents as they are held in the complex formation. Thus the water is rendered soft. The most commonly used sequestering agents are EDTA (ethyl diamine tetra acetic acid), NTA (nitrolo triacetic acid) and sodium hexametaphosphate.
Ion exchange method or zeolite process – Zeolites are hydrated silicates of sodium and aluminium. Hard water is made to percolate through the zeolite. In the chemical ion exchange reaction that takes place, any hardness is almost totally removed. Ion exchange units are available as attachments that can be fitted into the plumbing system at the point where the water supply enters the hotel.
Organic base exchange method - Organic base exchangers are synthetic resins containing the sulphonic and carboxylic acid groups. When hard water is passed through these resins, the acids react with the calcium and the magnesium salts to produce products which are non reactive. When the last two methods are used in succession, they yield very soft, pure.
DETERGENTS : -
These are cleaning agents that, when used in conjuction with water, loosen and remove dirt and then hold it in suspension so that the dirt is not re deposited on the cleaned surface. They can be of two types – soapy detergents and synthetic detergents (nn soapy). The three basic properties of a good detergent are :
1. Good wetting power – to lower the surface tension of water and enable the surface of the article to be thoroughly wet.
2. Good emulsifying power – to break up the grease and enable the dirt to be loosened.
3. Good suspending power – to suspend the dirt in the solution, thus preventing its re-deposition.
Composition and action of detergents
All detergents are primarily composed of three parts.
Active ingredients : - In soapy detergents, the active ingredient is obtained from natural oils and fats. These are composed of long fatty acid chains. The fatty acids commonly found in nature are the palmatic, stearic, oleic, and linoleic acids. These fatty acids occur in nature as triglicerides. The active ingredients in synthetic detergents are the surface active agents or surfactants obtained from petrochemicals. Surfactants are of four types. They are summarized in table 7.3.
| Anionic Cationic Amphoteric Non ionic |
| |
| Ionize in water Ionize in water Contain both positive Do not ionize |
| carrying a carrying a positive and negative charge in water |
| negative charge charge on the groups in the molecule |
| on the hydrophobic hydrophobic part |
| part of the molecule of the molecule |
| |
| Good wetting power Very weak clean- Used to impart soften- Have good |
| sing power, so ess and as dye fixer. emulsifying |
| never used alone. Powers. |
| Used to impart |
| softness and |
| counteract anionic |
| detergents in com- |
| bination. |
| |
| Limited suspendi- Blended with non- Have some germicid- Donot lather |
| ng power Lather ionics to give anti- dal properties as well as |
| very well. static and sanitizing anionic |
| properties. surfactants |
| |
| Constitute about Used in fabric soft- Used in fabric softe- Used in low |
| 20% of most eners, water repell- ners, dye fixin agents foaming det- |
| detergents. ents, and sanitizers. and other textile ergents, ideal |
| Include soaps Include quaternary textile auxillaries for use in |
| alkyl aryl sulph- ammonium comp- scrubbing |
| onates such as unds. machines |
| alkyl benzene They constit- |
| sulphonate, most ute about 6- |
| widely used 12% of liquid |
| surfactants synthetic det- |
| ergents and |
| about 2% of |
| most powde- |
| red detergent |
|
|
| Anionic detergents Cationic detergents Amphoteric deterg- Non-ionic |
| account for 80% used as neutral dete- ents are neutral detergents |
| of neutral synthet- rgent sanitizers in They are expensive are also used |
| ic detergents-wash- hospitals and food and are incorporated as neutral |
| ing powder, fluids, preparation areas. into speciality form- detergents. |
| floor cleaners and They donot have ulations such as They should |
| carpet shampoos. any smell.They are metal cleaners and be used in |
| pH is 7-9 also used in dusting oven cleaners in solutions |
| solutions. pH is of the stren- |
| below 7 gth recom- |
| . mended by |
| the manuf- |
acturer.
Various builders used in detergents Table 7.4
Helps remove stains | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| such as those of tea | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| and coffee. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Borax(sodium Acts at low pH as a | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| tetraborate) water softener. In | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| pentahydrate form | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| helps improve the free- | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| flowing property of | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| powders. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Sodium chloride Helps increase visco- | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| sity of an anionic | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| detergent. Enhances | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| detergency property | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| especially in case of | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| blood stained fabrics | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| and of woolens. Acts | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| as a bulk filler. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Magnesium sulph- Accts as a stabilizer | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ate for sodium perborate. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Helps eliminate stickiness | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| in powders using alkyl | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| benzene sulphonate. |
Builders – These give bulk to the detergent. A builder is a compound that has no surface active properties but increases the efficiency of the detergent. They are added to facilitate better handling and dilution. In case of liquid detergents, the diluents can be water; in case of powders, sodium sulphate is used. Builders can be inorganic or organic. The various types of builders are summarized table 7.4.
Additives- added to the detergent, these may be bleaching agents, blueing agents, fluorescent brighteners, enzymes, and so on. Optical brighteners or fluorescent brighteners help counteract the yellowing of fabrics that occurs with age. They are compounds that absorb ultraviolet light and reflect it back as blue light, creating an illusion of whiteness. Photo-activated bleaches, on the other hand, have an action that is chemical and not physical. They convert oxygen to nascent form when activated by sun light. Chelating agents are compounds capable of binding the mineral salts that make water hard. EDTA (ethylene diamine tetraacetic acid) and NTA (nitrilo triacetic acid) are chelating agents used in small amounts in detergents. They chelate calcium and magnesium salts.DTPA (diethyl triamine penta acetic acid) is used to chealte iron salts. Zeolites are also being used in some detergents. Hydrothropes help when, due to the presence of inorganic salts, the solubility of the liquid detergent decreases. Hydrothropes help to keep all the materials in solution. Enzymes such as proteases, lipases and amylases are incorporated in detergents to attack stains of different kinds. Advanced research has led to the development of enzymes that are stable up to temperatures of 60o C and a pH of 10.5-11. Their action is very slow and therefore they require a soaking time of 30 minutes or so. Perfumes are added to cover up the unpleasant smell of some synthetic detergents. Dyes, usually blue and green, are used to colour powdered detergents and make the product more attractive. Ground pumice is added to detergents to create a coarse texture so that stubborn dirt may be removed due to friction.
How detergents work
It is the surface active agents or surfactants in the detergent that are responsible for the three basic properties of detergents. Each molecule of the surfactant has a hydrophilic(wave loving) head and a hydrophobic (water heating), oleophilic (grease loving) tail. In other words, the hydrophilic head is attracted to water, whereas the hydrophobic tail is attracted by grease and repelled by water. When the detergent is added to water, the following actions take place:
Wetting action - The detergent lowers the surface tension of the water. The surfactant molecules tend to arrange themselves at the water-air interface. The hydrophobic tails of the surfactant molecules are repelled by water, creating a pull in the opposite direction to that of the inward pull of the water molecules .
Emulsifying action – The hydrophobic tails of the surfactant molecules are also oleophic in nature, that is they are attracted to grease. The tails thus penetrate the grease and lift off the fabric surface. The dirt also gets lifted away as it is entrapped in the grease.
Suspending action – Since the grease molecules are entrapped by the surfactant molecules, their contact with other surfaces is prevented. The grease (with the embedded dirt) is thus held in a stable emulsion in the water. This is also partly due to the fact that the hydrophilic heads at the other end from the grease molecules are attracted to water. Most of the surfactants now carry a mild charge, that is, they ionize and repel each other. This also aids in the suspending power of the detergent.
Figure 7.9 shows the role of surfactants in removing dirt from a surface.
Types of detergents
Various types of detergents are available for use in different areas and on different surfaces. Figure 7.10 summarises various types of detergents.
Soapy detergents/soaps – These are obtained when fat/oil is treated with an alkali. The process is called as saponification Soaps are relatively inexpensive. Soaps are effective only in soft water; in hard water they form a scum that is difficult to rinse away. Detergents from this category used in housekeeping are :
1. Toilet soaps – They are used in different kinds of packaging for guest rooms and cloakrooms. They contain perfume, dye stuffs, and antioxidants such as vitamin E. they donot contain any builders.
2. Soap powders – They dissolve rapidly in water and lather well, and comprise up to 40% of builders.
3. Soap flakes – The simplest form of all detergents, they dissolve easily and are used for delicate fabrics washed at lower temperatures.
Synthetic detergents – These are soap free and havr replaced the use of soaps in many cleaning processes. They are not affected by hard water and have good suspending powers. Based on their chemical nature, they may be neutral detergents (anionic, non ionic, cationic or amphoteric) or alkaline detergents as we have seen above. Alkaline detergents are used in the housekeeping departments, as they are very strong detergents, ideal for removing grease. They have a pH of 9-12.5. Though they do not foam much, they require thorough rinsing because of their slippery nature in solution. They will also patch the cleaned surface if not rinsed well. They are used on heavily soiled surfaces and for removing water-based floor polishes. Since they have such a high pH, they are harmful to the skin and therefore the staff must take special precautions while using them. However, the various categories of synthetic detergent in common use in housekeeping are:
Detergents
1. Liquid synthetic detergents – These are light duty detergents for hard surfaces and lightly soil fabrics. They contain 20% anionic surfactants and 6-12% non-ionic surfactants. They are neutral in reaction with pH 7.0
2. Powdered synthetic detergents – These are heavy duty detergents suitable for heavily soiled fabrics. They contain 20% anionic surfactants, 2% non ionic surfactants, about 33% alkaline builders, 9% bleach, 20% fillers, SCMC (sodium carboxyl methyl cellulose), brighteners and 15%water
3. Solvent based detergents – These contain water miscible solvents, builders, and anionic solvents. Their pH is 12 and they are used for stripping spirit based wax floor polishes. They are used for cleaning areas with a heavy accumulation of grease, as in the kitchen and on machinery.
4. Biological detergents - These are powdered detergents to which enzymes have been added, They are used to remove organic stains at a temperature of 40-50o C.
5. Disinfecting detergents – These are based on cationic surfactants, mainly ‘quats’ (quaternary ammonium compounds). They have good germicidal and antistatic properties. They are available as cleaning gels, air fresheners, and fabric conditioners. They may be used on floors, walls, equipment and areas that come into contact with the food.
The ideal detergent
Different types if detergents are used according to their suitability in cleaning various surfaces. However, the selection of detergents should be based on certain criteria to ensure that the optimal detergent ids bought and the housekeeper gets value for money. An is]deal detergent should - -
- Have good wetting, emulsifying powers.
- Readily dissolve in water
- Cleanse quickly with minimum agitation
- Be effective in all ranges of hard water, without producing scum
- Be effective over a wide range of temperatures.
- Be harmless to the skin and the surface to be cleaned
- Be easy to rinse away ; and
- Be biodegradable
Various ‘all purpose detergents’ are now available that combine most of the above qualities. However, buying the very best detergent will be of no use if the staff are not trained to use them in the correct way. Certain points to consider when using detergents are listed below :
- Dilute as per the manufacturer’s recommendations, using the measuring scoops and dispensers provided.
- Use the right detergent for the surface to be cleaned.
- Use protective gloves when using strong detergents.
- Dissolve the detergent thoroughly before use.
- Rinse away all traces of detergent from the surface and any cleaning equipment employed.
- Label detergent containers neatly.
- Store detergent containers in a dry, well-ventilated storage area.
- Wipe up any spilled detergent, as it may be a safety hazard.
ABRASIVES : -
These are substances or chemicals that depend on their rubbing or scratching action to clean dirt and grit from hard surfaces. They are used to remove very stubborn stains on various surfaces.
Types of abrasives
Based on the classification of hardness for various substances shown in fig.7.11, abrasives are classified as :
1 2 3 4 5 6 7 8 9 10
Talc Calcite Feldspar Diamond
Fig. 7.11 Scale of hardness
Fine abrasives – These include precipitated whiting (filtered chalk) and jeweler’s rouge (a pink oxide of iron) used for shining silver. They are also constituents of commercial silver polishes.
Medium abrasives – These include rotten stone, salt, scouring powder and scouring paste. Scouring powders are made up of fine particles of pumice mixed with a soap/detergent, an alkali and a little bleach.
Hard/coarse abrasives – These include bath bricks, sand paper, pumice, steel wool and emery paper.
Glass paper, calcite, sand paper, fine ash, emery powder and paper, jeweler’s rouge, powdered pumice, precipitated whiting (filtered chalk), feldspar, ground limestone, sand, carborundum, steel wool and nylon scourers are some commonly used abrasives.
| Surface | Abrasive |
| Brass Ceramics | Abrade with emery. Abrade with carborundum and water. |
| Copper | Abrade with emer. |
| Glass | Abrade with carborundum. |
| Gold | Abrade with fine emery. |
| Lead, tin Leather | Abrade with fine emery. Degrease with care and abrade with glass paper. |
| Silver | Abrade with fine emery. |
| Steel, iron Stone Wood | Abrade with emery. Abrade with wire brush. Abrade with fine glass paper or fine wool. |
Abrasives are usually not used alone in cleaning agents. For example, cream or paste meant for cleaning utensils contains about 80% of finely ground limestone, along with other substances such as bleachers, anionic surfactants, alkaline builders and perfumes. The use of various abrasive agents for cleaning different surfaces is summarized in table 7.5
REAGENTS : -
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Types of reagents
Reagents may be acids or alkalis.
Acids used as cleaning agents may vary from mild acids (such as acetic acid) with a pH of 3 to strong acids( such as dilute or concentrated hydrochloric acid )with a pH of 1. Mildly acidic substances used commonly in cleaning include lime, tamarind and buttermilk. Acids may be used in solution alone or may be a part of some special formulations, as in toilet cleaners. Housekeeping staff need to be trained in the safe handling of strong acids, as they are highly corrosive. They literally eat away dirt. Rubber gloves should always be used while handling them. They should be used in very small quantities as they emit toxic fumes as well. Strong acids should be thoroughly rinsed away after the cleaning process. Table 7.6 summarizes the use of different acids in cleaning.
Acids and their use in cleaning
| Acid | pH | Uses |
| Concentrated HCL (once referred to as ‘spirits of salt’) | 1 | Removing stubborn hard water deposits. |
| Dilute HCL | 1 | Removing stubborn scales and deposits from sanitary ware. |
| Oxalic acid | 2 | Removing stubborn hard water deposits. |
| Acetic acid | 3 | Removing tarnish and stains from metals such as copper and brass(the acid must be washed off quickly). Neutralizing alkalis used in cleaning. Preventing colours from running during washing. |
| Sodium acid sulphate | 5 | Removing hard water deposits and scales from toilets. |
| | | |
| | | |
Alkalis are used as cleaning agents in the form of liquids and powders. They are particularly useful in the laundry. Very strong alkalis should be used with the utmost caution as they are corrosive and toxic. These are called caustic alkalis. Many alkalis act as bleaches. Caustic soda based cleaning agents are used to clear blocked drains and to clean ovens and other industrial equipment. Ammonia is a strong grease emulsifier and should also be carefully used as it emits strong fumes. It is also added to abrasive formulations. Toilet cleaners to which bleach has been added are very effective. It should be kept in mind that sodium chlorite bleach should never be used with an acidic toilet cleaner, however, as it will release toxic chlorine gas. The use of alkalis in cleaning is summarized in table 7.7.
| Acid | pH | Uses |
| Sodium hydroxide(caustic soda) | 14 | Removing stubborn grease from ovens and equipment. Clearing blocked drains. |
| Ammonia | 11 | Removing stubborn grease. |
| Sodium carbonate(washing soda) | 10 | Used as an alkaline builder in synthetic and soapy detergents. Clearing blocked drains. |
| Sodium perborate | 10 | Removing stains and whitening due to bleaching action at higher temperatures (above 40o) |
| Sodium hypochlorite | 9 | Removing stains and whitening due to bleaching action on various types of surfaces. Acts as disinfectant. |
| Sodium bicarbonate(baking soda) | 8 | Removing stubborn grease from smooth, delicate surfaces. Removing stains such as tea,coffee and fruit juice. |
| Sodium pyroborate (borax) Sodium thiosulphite | 8 7 | Same as above. Removing iodine stains. |
Organic solvents:
Grease is soluble in organic solvents such as tetrachloride, acetone, turpentine, & methylated spirit. Thus, these organic solvents are used extensively in the removal of grease, dry-cleaning of fabrics, & stain removal. Solvents are also useful in cleaning surfaces that may be harmed by water. Organic solvents evaporate rapidly from a surface & are therefore ideal for cleaning glass surfaces such as mirrors & windows.
Disinfectants & bleaches:
Disinfectants aid in the cleaning process by bringing about varying ranges of microbial control. The term ‘disinfectant’ is now used as a general term that covers all kinds of agents that bring about germ control. Most disinfectants have a strong smell & therefore should be used only in recommended amounts in areas where germ control is required.
Varying ranges of microbial control:
| Microbial control | Action |
| · Disinfection · Bactericidal · Bacteriostatic · Antiseptic · Sanitation · Sterilization | Killing most microbes , but not their spores Killing most bacteria, but not their spores Making the environment non-conducive for the growth & reproduction of bacteria. Making the environment non-conducive for the growth & reproduction of disease causing (pathogenic) microbes. Reducing the microbial count to an acceptable level. Killing all kinds of microbes as well as their spores. |
Type of disinfectants:
Disinfectants can be categorized in terms of their chemical action and composition:
Phenols: These are hydroxyl derivatives of the aromatic hydrocarbon benzene. They are used in dilute or high concentrations to disinfect surfaces in hospitals especially. In hotels, diluted phenols are used with their sharp smell masked by other additives.
Halogens: The elements chlorine & iodine may be used as disinfectants. Chlorine is used both as bleach & as a disinfectant on many surfaces. Iodine is not often used to disinfect surfaces because it tends to leave brown stains.
Quaternary ammonium compounds (‘quats’): these are cationic surfactants useful as bacteriocides.
Natural pine oils: pine oils are obtained from pine trees. They are germicidal to some extent, but are mainly added to cleaning formulations for their pleasant smell.
Guidelines for using disinfectants
Certain points to consider while using disinfectants are given below:
· Clean the surface first with detergent & rinse with soft water only.
· Rinse away the detergent solution thoroughly before using a disinfectant on the surface.
· Use the correct disinfectant for the range of disinfection required.
· Use the disinfectant at the correct dilution for it to be effective. Different surfaces may require different dilutions of the same disinfectant.
· Allow the recommended time for the disinfectant to act.
Bleaches used in cleaning of hard surfaces are stabilized solutions with a high pH. The alkali sodium hypochlorite acts as powerful bleach & is used on WCs & sinks for the removal of stain.
Glass cleaners:
These are composed of an organic, water-miscible solvent such as isopropyl alcohol & an alkaline detergent. Some glass cleaners also contain a fine, mild abrasive. Most glass cleaners are available as sprays or liquids. They are sprayed directly onto windows, mirrors, & other glass surfaces or applied on with a soft cloth & rubbed off using a soft, lint free duster. A glass cloth is ideal for the purpose. Soft water to which some methylated spirit or vinegar is added is an inexpensive glass cleaner that can be readily made in the housekeeping department.
Deodorizers:
Deodorizers aid in the cleaning process by counteracting stale odors & sometimes also introducing a fragrance to mask them. They are used in restrooms, guestrooms, guest bathrooms, cloakrooms, & public areas such as lobbies. Some deodorizers leave no trace of a perfume cover-up. They are usually available as aerosols sprays, liquids, powders & crystalline blocks. The crystalline blocks are effervescent & manufactured using the principal of time- released aromatic chemicals. Naphthalene balls also serve as effective deodorizers. If thorough cleaning & good ventilation are provided, money need not be spent on expensive deodorants.
Toilet cleaners:
These are strong, concentrated cleaning agents designed to clean & disinfect WCs & urinals. They are available in liquid, powder & crystalline forms. They are acidic in nature as their main function is to remove stubborn stains & lime scale. They all contain some form of disinfectant.
Liquid toilet cleaners: These contain dilute hydrochloric acid, bleach, & pine oil. Adequate protective gear should be worn by the user while using such a toilet cleaner.
Crystalline toilet cleaners: These contain sodium acid sulphate, anionic surfactant & pine oil.
Powdered toilet cleaners: These cleaners contain a soluble acidic powder, chlorinated bleach, a fine abrasive & an effervescing agent to help the active ingredient spread in water.
Whatever form of toilet cleaner used, they should never be mixed with other cleaning agents since harmful gases may be produced in the resulting reaction.
Polishes:
These chemicals produce a shine by providing a smooth surface from which light is reflected evenly. Polishes are primarily applied to form a hard, protective layer & thus guard against finger marks, stains & scratches. They also create attractive sheen on the hard surface.
Classification of polishes:
Polishes are used on metal, furniture, & flooring & are classified according to the type of surface they are used on. On metals, they also smooth out any unevenness on the surface of the article and in case of flooring & furniture, they provide a smooth protective layer.
Metal polishes: These remove the superficial tarnish that forms on metal surfaces due to the attack of certain compounds in the air & some foodstuffs. These polishes also eliminate any scratches on the metal. They consist mainly of a very fine, mild abrasive, generally either precipitated whiting or jeweler’s rogue. Most polishes also contain a fatty acid, a solvent & water. On buffing, they remove tarnish & produce a shine. In hotels, hard surfaces where metal polishes are used include door-plates & handles, foot rails in bars, staircase banisters, ashtrays, bathroom fittings, tableware & cutlery. In metal polishes such as Brasso & silvo, the grease solvent or acid mixed with the abrasive powder aids in the removal of tarnish. Long term polishes contain some ingredients that coat the surface of the metal & retard the process of tarnishing in future. Metal polishes are available in the form of milky or clear liquids & of powders. Care should be taken in applying the correct polish as polishes meant for hard metals may damage the surface of soft metals. Because of their solvent content, metal polishes have a strong smell & should be used in well-ventilated room to let fumes dissipate. The container should be closed immediately after pouring out the polish into the polishing tray. If not, the solvent in the polish will evaporate, rendering it ineffective.
Certain recommendations on the use of metal polishes are given below:
· Cover the surrounding area with the newspaper or protective sheets.
· Carry out any polishing work in a well- ventilated room.
· Use an appropriate polish applicator or disposable rags.
· Use cocktail stick covered with rag to apply polish in narrow, hard –to-reach nooks & corners.
· Remove polish with cotton or a soft, dry cloth.
· Buff the polish with rags & dusters, preferably with ones with a napped surface.
· Wash any polished cutlery in warm detergent solution before use.
· Leave the area & equipment clean & tidy after polishing work is complete. Dispose off rags & newspapers used.
Classification of polishes:
Furniture polishes:
These contain wax or resin, a solvent, water & silicone. The wax or resin helps to keep the furniture surface supple. It also protects against abrasion & absorption of stains & spills. The main role of wax, however, is to provide a smooth surface from which the light is reflected evenly, producing an attractive sheen. The types of waxes commonly used are carnauba, beeswax, ozokerite, and paraffin wax. The solvent and water are meant to remove grease stains and water-soluble stains, respectively. Silicone is used to make the polish easier to apply. It also gives an added gloss and improves resistance to moisture, heat, dust and smears. Silicones thus give a harder and longer-lasting finish. Furniture polish needs to be applied frequently only in the case of untreated, unvarnished wood. Painted and varnished furniture should not be varnished too often. Most pieces of furniture manufactured these days are polished with a permanent synthetic resin and thus do not require further application of polish. As a preventive maintenance activity, they can be buffed regularly with a duster during dusting. As seen in figure 1 furniture polishes are available in various forms, differing in their wax contents.
Paste polishes These have a higher percentage of wax (25-30 percent). They may or may not contain silicones. They are ideal for use on antique wooden furniture. Pastes should be applied in small amounts buffed for a long time to get the desired result, and care should be taken to remove all traces of excess polish from the carved areas afterwards,
Cream polishes These have a high percentage of solvent. They contain light-colored waxes. Creams need to be used on furniture with a gloss finish only as they gradually increase the shine after continual use on the surface. Because of the higher solvent content, they have a strong smell and should be used in a well-ventilated room to let the fumes they exude dissipate completely. They are applied with a dry or damp rag and the surface polished up immediately with a dry duster.
Liquid polishes These too have a high percentage of solvents. They contain about8-12 percent wax. In addition, they may also contain a dye that can mask scratches on the surface of varnished furniture. They are used on glossy finishes to remove grease marks and other stains. They should be applied with a dry rag and buffed up with a soft, dry cloth while still moist to produce a good sheen.
Spray-on polishes these contain about 8 percent wax and a high amount of silicone. Spray contains aerosols to make their application simpler. These polishes clean as well as polish, and pre-dusting of the surface is not required. They are ideal for use on non-porous surfaces such as glass, chromium, plastic, and varnished or gloss-painted wood. They produce the static electricity on the surface so that dust is not attracted readily. The ideal way to apply a spray polish is to first spray it on the duster and then rub this on the surface. This minimizes wastage, an important consideration for these polishes especially, as they are expensive.
Certain points should be kept in mind while working with furniture polishes;
· Apply the polish on the clean surface
· Use the least quantity required to accomplish a good polishing of the surface; else it may result in stickiness that will attract more dust.
· Use soft, disposable rags for applying polish to the surface, except in the case of a spray-on polish.
· Always keep the polish container closed when not in use, else the solvent will evaporate and polish will dry out.
· Use polishes undiluted, unless it is specified otherwise by the manufacturer.
· Be careful while using polishes with a high solvent content since they are flammable.
Floor polishes:
These have a two-fold function. They not only lend an attractive sheen to the surface, but also provide a protective coat on it. Floor polishes should not be applied too frequently. They should be used only when simple buffing does not produce the desired sheen on the floor. The main aim in using floor polishes is to deposit a layer of wax on the surface. Therefore they are also referred to as floor waxes. The right kind of polish should be used along with the right equipment. Polish applicator mops should be labeled neatly with the kind of polish they are each used for to avoid mixing of products. The wrong polish may easily damage a floor surface and mar its appearance. The two basic types of floor polishes are spirit/solvent based and water-based floor polishes. A special group of floor polish called high speed emulsion polish is also discussed below.
Spirit/solvent-based polishes this kind of polish may be in the form of a liquid or a paste. They contain a blend of waxes and silicone dispersed in a solvent (a white spirit or Freon).) The waxes used may be natural (carnauba or ozokerite or synthetic (polyethylene). After the polish has been applied to the floor, the solvent evaporates and the wax left behind is buffed up using a polishing machine. The silicone helps in easy application of the polish and gives a more lasting finish. Additives such as perfumes and dyes are also added to solvent-based polishes. Solvent-based polish is used on porous floors such as wood, wood composition, cork magnesite and linoleum.
Water-based polishes These are available in the form of creamy liquid emulsion containing a blend of natural (carauba and montan) and synthetic waxes suspended in water by means of an emulsifying agent (ammonia or a synthetic detergent). They account for 80-85 percent of all floor polishes manufactured. After the polish has been applied to the floor, the water evaporates and the wax is deposited on the surface in a hard film. Colloidal silicon is sometimes added to water-based polishes as an anti-slip agent. Plasticizers and either alkali-soluble resins or metal-complexed polymers are also added. Plasticizers aid in the easy application of polish. Alkali-soluble resins are meant to provide weak break points in the water-based polish to facilitate cleaning with alkaline detergent solutions. The metal in the metal-complexed polymers shields the break points against the penetration detergent solutions. Usually only occasional buffing is required for these polishes. They are therefore also referred to as dry-bright polishes. Often these polishes are made into liquid sprays by addition of high amounts of emulsifying agents. The polish is then sprayed on and buffed immediately. Water-based polishes may be fully buffable (containing 45-60 percent wax and 20-40 percent polymers), semi-buffable (containing 25-40 percent wax and 45-60 percent polymers), or dry bright (containing 5-15 percent wax and 50-70 percent polymers). The amount of wax determines the amount of waxing required to achieve a desirable amount of shine. These polishes are not meant for porous surfaces, as water will damage them. Water-based polishes are used on porous floors only when they have been sealed properly. These polishes are used mainly on semi-porous surfaces such as thermoplastics, PVC, rubber, asphalt, terrazzo, marble, and natural materials such as Cuddapah tiles and so on.
Some guidelines on the use of floor polishes are given below:
· Use an appropriate sign to warn people walking along that area of the fact that floor polishing is being carried out.
· Ventilate the area well before starting.
· Apply the polish to clean, dry floor.
· Rinse the floor thoroughly using a neutralizing agent such as diluted vinegar after stripping the old polish.
· Apply several thin coats of polish rather than few thick coats.
· Work systematically to ensure that all the areas are covered.
· Allow sufficient drying time before applying the second coating.
· Buff thoroughly to reduce the slipping hazard.
· Remove any extra build-up of polish with an appropriate abrasive pad.
· Leave all polishing equipment clean and store them properly
Leather polishes These contain a special blend of waxes, a spirit solvent, and occasionally a dye. They are available in the form of creams and liquids. They help keep the leather supple and impart sheen to it. They also prevent deterioration of old leather articles.
Some do-it-yourself polishes
Some methods of making do-it-yourself (DIY) polishes are presented in the tables. When unsure about applying polish to a surface, first apply it on a small area not in view.
Floor sealers
These are applied to flooring surfaces as a semi-permanent finish that acts as a protective barrier by preventing the entry of dirt, girt, liquids, stains, grease, and bacteria. They prevent scratching and provide an easily maintainable surface. The right type of seal should be applied to each type of floor for effective protection and an attractive appearance. According to their functions, floor sealers can be finishing, protective, or a combination of both.
Furniture polish for dark wood: furniture polish for all types of wood:
| Ingredients | Amount |
| turpentine methylated spirit linseed oil vinegar | 2 parts 1 part 2 parts 1 part |
| Method: combine all ingredients in a bowl and shake well to form an emulsion | |
| Ingredients | Amount |
| Beeswax Turpentine | 25 g 25 ml |
| Method: heat the beeswax on a moderate flame till it melts. Remove from flame, add turpentine and stir well till the mixture is cool. | |
Furniture polish for light colored wood:
| Ingredients | Amount |
| white wax petrol | 1 part 2 parts |
| Method: break the wax into small bits and put in a lidded can. Add petrol and shake well till it becomes creamy | |
Cream polish for leather and wooden furniture:
| Ingredients | Amount |
| Soap (shredded) Water Beeswax( shredded) White wax(shredded) turpentine | 1 tbsp 1 cup 2 tbsp 1 tbsp 1 cup |
| Method: place the beeswax and white wax into a bowl. Mix in turpentine so that the waxes are submerged in it. Heat the mixture over a water bath till the waxes dissolve. Combine the contents of the two bowls. Beat the mixture to a creamy consistency. Store in wide-mouthed bottles | |
They are also grouped as permeable, semi-permeable and impermeable, according to their penetrability vis-Ã -vis water. Permeable seals can be used on wood, cork, stone( except slate), and magnetite floors. Impermeable seals should be avoided on these floors as moisture naturally found within these floors will then get entrapped and may cause disintegration of the flooring. Impermeable seals may be used on PVCs, thermoplastic tiles, and rubber floors.
Sealers may be reinforced by the application of floor waxes. Floor sealing should always be done on a clean and dry surface. Most sealers require a hardening time of 12-16 hours and 2-3 coats are recommended
Types of floor sealers
There are six main types of floor sealers, depending on their composition.
Oleo-resinous sealers these are clear, solvent-based sealers used on wood, wood-composition, cork and magnetite floors. That consists of oils, resins, solvents, and driers. They not only impart an attractive surface gloss, but also penetrate the floor, darkening the colour and highlighting the grain of wood floors. They are comparatively cheaper than other sealers.
One-pot plastic sealers these are also called one-can sealers. They are made up of synthetic materials. They impart a gloss to the floor surface but do not penetrate it. They are used on wood, wood-composition, cork, and magnetite floors. Polyurethanes can also be used on concrete the three types of one-pot plastic seals are:
1. Urea-formaldehyde resin with an acid catalyst.
2. Oil-modified polyurethane.
3. Moisture-cured polyurethane
Two-pot sealers this type of sealer is composed of a base such as urea-formaldehyde or polyurethane and an accelerator or hardener. The two components are kept separate until use, else a chemical reaction occurs between them and the mixture hardens in the can. Because of the separate components, the shelf life of these sealers is longer. The accelerator in itself has a shorter shelf life, however. The two components should be mixed in the recommended proportions; else the sealer will not harden and will result in a patchy finish. This type of sealer should be used in a well ventilated room as they smell strongly of solvent fumes. They may be used on wood, wood composition, cork, and magnetite floors.
Pigmented sealers as the name implies, these sealers contain color pigments, which, apart from providing color, also strengthen the sealer. They may be used on concrete, wood, wood-composition, magnesite floor, asphalt, and stone floors. There are two types available:
1. One-pot synthetic rubber
2. Two-pot polyurethane.
Water-based sealers these are composed of acrylic polymer resin and a plasticizer. The particles of the resin penetrate the pores on the floor surface to provide a plastic skin. These are less durable sealers and should be reinforced with a water-based floor wax. However, they can easily be touched up, removed, and renewed. They may be used on marble, terrazzo, magnesite, linoleum, rubber, thermoplastic tiles, PVCs, asphalt, concrete, stone and quarry tiles.
Silicate dressings these consist of a base of sodium silicate dissolved in water. This is not a true sealer. The sodium silicate reacts with the lime in concrete floors to form insoluble calcium silicate. The water acts as a carrier, and after it evaporates, silicate glass is formed. These simply reinforce concrete and stone floors, and prevent the accumulation of dust on their surface. Silicate dressings are much cheaper than sealers.
Selecting the right sealer
Most sealers are expensive. So a lot of thought should be put into buying the ideal seal for the particular flooring to get maximum durability and value for money. The following points need to be kept in mind while selecting floor sealers:
· The type of floor
· The amount of traffic in the area
· The availability of the floor for future sealing
· Good fixing or ‘keying’, durability, appearance and anti-slip qualities
· Ease of application, repair, removal, and renewal
· Odor and fumes
· Drying time
· Shelf life
· Cost-effectiveness
Applying floor sealers
Whichever type of floor sealer is chosen, the following recommendations should be followed while applying floor sealers
· Use appropriate signs to warn passer-bys that sealing is being carried out, else it may be a safety hazard
· Ensure the floor surface is clean, chemically neutral and dry before applying the sealer. Otherwise the seal will not ‘key’ to the surface
· Maintain an ideal room temperature of 21oC
· Keep the room well ventilated
· Protect the area from flies and pests until the sealer is dry
· Keep on hand only the required amount of sealer and store the rest tightly lidded, else the whole bulk may deteriote
· Apply several thin coats rather than a few thick ones
· Allow the recommended drying time between coats.
· Clean & store all equipment, such as sealer applicators, neatly after use.
Floor strippers:
These are used to remove a worn-out floor finish so that a new sealer or polish can be applied. Most are based on ammonia & the other is a non- ammoniated product. Ammonia has an intense odor & therefore the area treated should be well ventilated for many days to get rid of the smell. Alkaline detergents with a high pH are also used as floor strippers. It should be kept in mind that any residual stripper solution needs to be rinsed away thoroughly with a mildly acidic rinse. The ideal way is to add vinegar to the last rinse of water.
Carpet cleaners:
These are composed of neutral water-soluble solvents, emulsifiers, de-foamers, soil repellents, sanitizers (occasionally), optical brighteners & deodorizers. They are available as sprays, powders, foams & liquid shampoos. Whichever type is selected, it is essential that they be used in the correct dilutions.
Some common cleaning agents
Some common cleaning agents used in professional housekeeping are as follows:
Ammonia: Liquid ammonia is a solution of ammonia gas in water, held as ammonium hydroxide. It is a strong alkali used for softening water, cleaning window panes & emulsifying grease.
Bath brick: This is a reddish- brown powder, also obtained in brick form. It is used for scouring & polishing metals such as brass & copper. In powdered form, it is used for cleaning earthenware.
Benzene: Obtained from the distillation of coal tar, benzene is used as a grease solvent & for removing paint & tar stains.
Borax: Chemically sodium borate, this white crystalline powder is used to soften hard water & to remove coffee & tea stains.
Bran: The husk of wheat grain, it is used in dry-cleaning as grease absorbent.
Fuller’s earth: This is ash- white clay that readily absorbs grease. It is used on colored wood surfaces.
Hydrochloric acid: this is corrosive & poisonous mineral acid, used diluted for removing stains in bathrooms.
Jeweler’s rogue: Chemically this is ferric tetroxide a pinkish powder used for polishing silver. It is constituent of commercial silver polishes too.
Lemon: Lemon is used for removing ink stains from wooden surfaces.
Linseed oil: This is obtained from crushed seeds of the flax plant. It is a constituent of furniture polishes & paints. It darkens unpainted wood slightly.
Magnesia: chemically magnesium carbonate, this fine white powder is used for dry- cleaning felt, fur & woolen articles.
Methylated spirits: This is used for cleaning window panes & mirrors to a shine. It is a constituent of varnishes & lacquers.
Oxalic acid: This is an organic acid used for the removal of stains from fabrics & bath fittings. It is also used for cleaning porcelain.
Paraffin oil: Not to be confused with paraffin wax, this liquid is a product of distillation of crude petroleum & is used for cleaning greasy iron & steel articles. It also cleans greasy earthenware when used in combination with bath brick.
Petrol: This too is obtained from petroleum distillation. It is highly inflammable & is used for dry cleaning & for removing grease stains.
Pumice: This is a light, porous rock of volcanic origin. It is used as an abrasive for hard metals, earthenware & enamel.
Rotten stone: This is a decomposed siliceous limestone & is used for cleaning copper, brass & earthenware.
Common salt: Chemically sodium chloride, this is used as a medium-grade abrasive. It is used for stiffening the bristles of brushes & stiff brooms. Salt is also added as a mordant while washing colored clothes. (A mordant is a substance that prevents undue loss of color while washing clothes)
Sand: This hard compound of silica is used as a hard abrasive on stone floors & hard coarse wood.
Sawdust: It acts as an abrasive & a grease absorber.
Shikakai: Sometimes called soap-nut or soap berry, but more accurately soap-pod (to distinguish from the fruit of reetha). This is used for non abrasive cleaning of tarnished metals.
Soda: It emulsifies grease &aids in the cleaning of dirty pans.
Steel wool: This is steel manufactured in to long filaments, in varying grades of fineness. It is used for scouring hard metals & dirty pans.
Turpentine: This is constituent of paints. It is also diluents for paints & removes tar stains.
Vaseline: this is obtained as a residue in petroleum distillation. It prevents rust formation on metals, acts as a lubricant & may be applied on leather to make it soft & supple.
Vinegar: Chemically this is 4% acetic acid. It is used to remove stains & tarnish from metals such as copper. It is also effective in removing streaks from glass surfaces such as window panes & mirrors.
Whiting/ precipitated whiting: Chemically this is calcium carbonate in pure form. It is used as a mild abrasive on soft metals & in cleaning white-painted articles.
Selection of cleaning agents:
The use of cleaning agents is meant to save time, effort & money. If selected well, all the three objectives may be fulfilled. The following points need to be considered when selecting cleaning agents:
· The type of soilage
· The type of surface
· Odor
· Range of action or versatility
· Composition of the cleaning agent
· Ease of use, saving of effort & time
· Toxicity or side effects
· Shelf life
· Packaging volumes & quantities
· Cost effectiveness
Storage of cleaning agents:
Cleaning agents with a longer shelf life are usually bought in bulk because of the reduced costs that accure from the economies of scale. Other agents are bought & replenished periodically. Storage of cleaning agents is crucial & the various points to be kept in mind are mentioned below:
· Ensure that the storage racks are sturdy. Heavier containers must be kept on the bottom shelf.
· The store should be kept clean & well- ventilated at all times.
· Label all containers neatly with a waterproof marker.
· Ensure that the lids are tightly secured.
· When dispensing cleaning agents, use appropriate dispensers & measuring apparatus.
· Ensure that no residual deposits of cleaning agent are left around the rims of the containers.
· Avoid spillage; if a spill occurs, clean it up immediately.
· Follow a systematic procedure for rotating stocks.
· Organic solvents, strong reagents, polishes, & aerosol- based agents should be kept away from heat sources.
· Check stocks regularly. The format of a stores stock sheet is shown below:-
· The store should be kept locked when not in use.
| STORES STOCK SHEET Date:-
|
· Format of a stores stock sheet.
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