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CHEMICALS AROUND US


A. Classifying Household Chemicals
There are things in our house that is made of chemicals. Even our body consist of these similar chemicals. To find out the chemicals substances that we use in our house, let us do this activity:
1. Observe things in your house that contain chemicals.
2. Write the chemicals that contained in it.
Chemicals can be obtained from living or non living things. Chemicals that are derived from living creature such us gasoline and diesel oil. Chemicals that are obtained from non living things such as iron and gold.



B. Cleaners
When we start using cleaner in our lives? Human has been used cleaner since long time ago, the difference is long ago people used natural substances that they get from their environment, but now we tend to use cleaners that are made in factories and in various amount.
Cleaners that are widely used are soap and detergent. We’ll discuss about it one by one.

1. Soap
Soap is made from natural products such as animal fat and plant oil. Soap is made with a reaction that known as saponification reaction, in this reaction fat and oil is reacted with solution of sodium hydroxide (NaOH) or potassium hydroxide (KOH) which produce soap.
The making of soap is basically the same (now and then) only in the making of several types of soaps other substances are added. These substances such as cream, perfumes, and vitamins. Cream is used to smooth the skin, perfume is for good smell for the soap, and vitamin is used for skin rejuvenation. Some soap are added with colorings to make it seem interesting.
Dirt that is attached to skin or clothes usually contain fat or oil. Fat and oil is not water soluble, that is why when we take a bath or wash our clothes we not only use water alone, but we also use soap. Soap can lift the dirt off the skin or clothes.

Fig.1 Soap                                                      Fig.2 Soap cleaning process ilustration
Disadvantages of soap
Today, fat-based soaps have mostly been superseded by modern detergents. Washing agents do not contain soap for cleaning fabric, but for reducing foam.
The disadvantages of commercial soaps are:
• Most commercial soaps have had their glycerine removed for use in other industries, which deprives the skin of the natural, moisturizing glycerine and generally leaves the skin feeling dry.
• Some antibacterial soaps have antiseptic chemicals that can kill "healthy" bacteria that live symbiotically on the skin's surface and contribute to skin health. There is a theoretical risk of antibacterial additives, such as Triclosan, in soaps contributing to antibiotic resistant bacteria, however, controlled studies have not borne out that conclusion. When Triclosan is discharged into the environment and exposed to sunlight, it breaks down to yield dioxins.
• Soap-based products often contain the additive detergent sodium laureth sulfate, which research has found to be harsh on skin. This product is also present in many non-soap cleaners for personal hygiene (shampoos, bathfoams, toothpaste, etc.).
• Poorly finished soaps may contain excess alkali (NaOH) and react mildly basically with skin and fabric; Most handmade and commercial products are finished to neutrality or to a weak acid content to prevent this and be more compatible with the skin's slightly acidic pH.
• Commercial products use chelating molecules (sequestrants), often EDTA derivatives to bind with any free Ca or Mg ions and prevent soap scum. These also help reduce fragrance loss, discoloration and rancidity.
• Castile soap has a very high alkalinity level, measured at about 9. pH of skin and hair has a slightly acidic pH level known to be about 5 to 6. Due to the high pH level, soapmakers who market liquid castile soap do not usually recommend it for washing hair, because it may cause hair to become dry. Those that do often recommend an acidic final rinse, such as with diluted vinegar, to restore the pH and remove any soap scum resulting from rinsing with hard water.
2. Detergent
Detergent is one of the cleaner that is used to clean clothes; it’s firstly used in 1940. Detergent that we know today usually in the form of powder. We use detergent by dissolving some amount of detergent powder in the water. People choose to use detergent than soap to clean clothes; this is because the power of detergent to clean is stronger than soap. Detergent can lift the dirt that attached on the clothes off, and there is some perfume added to it so the clothes that is cleaned smells good.
Beside that, detergent also contains some substances that prevent the dirt that already detached from the clothes to re-attach to the clothes that already cleaned.

                                          Fig.3 kind of deterjen

Composition of detergent
Detergents, especially those made for use with water, often include different components such as:
• Surfactants to 'cut' grease and to wet surfaces
• Abrasive to scour
• Substances to modify pH or to affect performance or stability of other ingredients, acids for descaling or caustics to destroy dirt
• Water softeners to counteract the effect of "hardness" ions on other ingredients
• oxidants (oxidizers) for bleaching and destruction of dirt
• Non-surfactant materials that keep dirt in suspension
• Enzymes to digest proteins, fats, or carbohydrates in dirt
• Ingredients that modify the foaming properties of the cleaning surfactants, to either stabilize or counteract foam
• Ingredients that affect the aesthetic properties, such as optical brighteners, fabric softeners, colors, perfumes, etc.
Detergent choice
There are several factors which dictate what compositions of detergent should be used—namely the material to be cleaned, the apparatus to be used and tolerance for dirt. For instance, all of the following are used to clean glass. The sheer range of different detergents which can be used demonstrates the importance of context in the selection of an appropriate glass-cleaning agent.
• A chromic acid solution is used to get glass very clean for certain precision-demanding purposes, namely in analytical chemistry,
• A high foaming mixture of surfactants with low skin irritation—for hand washing of drink glasses in a sink or dishpan,
• Any of various non-foaming compositions—for glasses in a dishwashing machine,
• An ammonia-containing solution—for cleaning windows with no rinsing,
• Ethanol or methanol in Windshield washer fluid is used for a vehicle in motion

3. Other cleaning substances
The advances of technology produce various synthetics chemicals. For example floor cleaners, glass cleaners, etc. These cleaners contain different chemicals according to its function. Some contain hydrochloric acid or citric acid or sodium chloride and others.
To know and understand the chemical that is contained in a cleaning product let us do this activity:
1. Find a cleaning product in your home.
2. Write down some chemicals that it’s contained.
3. Find some information about the function or usage of each chemical in every product.
4. Write your findings in a table.

C. Bleacher
Bleacher is used to clean stain on clothes, it is also able to kill bacteria (act as a disinfectant). Bleacher is able to break the bonds in the stain molecules and then release it from the clothe fabrics. Bleacher usually contain 5,25 percent sodium hypochlorite solution.
Bleacher must be use in a careful manner. Clothe can be damaged by it. Some fabrics such as polyesters may have a color change to a yellowish color and also can damage the fabrics.

Fig.4 kind of bleacher

Type of bleach
- Chlorine dioxide is used for the bleaching of wood pulp, fats and oils, cellulose, flour, textiles, beeswax, and in a number of other industries.
- In the food industry, some organic peroxides (benzoyl peroxide, etc.) and other agents (e.g. bromates) are used as flour bleaching and maturing agents.
- Peracetic acid is used in paper industry to produce totally chlorine free (TCF) paper.
- Not all bleaches have to be of an oxidizing nature. Sodium dithionite is used as a powerful reducing agent in some bleaching formulas.

D. Fragrance and Deodorant
Fragrance is not perfume only, it can be contained also in air freshener, floor or clothe cleaners, etc. Fragrance that is contained in perfume usually in the form of flowers or fruit scents. This scent comes from a certain compound such as citral (lemon scent), geranial (rose scent), irone (violet scent), etc. Fragrance usually found in nature. But experts are trying to make synthetics fragrance that has the similar scent with the natural product.

Fig. 5 Kind of fragrance

Concentration levels of perfume
Perfume oil is necessarily diluted with a solvent because undiluted oils (natural or synthetic) contain high concentrations of volatile components that will likely result in allergic reactions and possibly injury when applied directly to skin or clothing.
By far the most common solvent for perfume oil dilution is ethanol or a mixture of ethanol and water. Perfume oil can also be diluted by means of neutral-smelling lipids such as jojoba, fractionated coconut oil or wax. The concentration by percent/volume of perfume oil is as follows:
• Perfume extract: 20%-40% aromatic compounds
• Eau de parfum: 10-30% aromatic compounds
• Eau de toilette: 5-20% aromatic compounds
• Eau de cologne: 2-5% aromatic compounds

E. Insecticide
An insecticide is a pesticide used against insects in all developmental forms. They include ovicides and larvicides used against the eggs and larvae of insects. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind the increase in agricultural productivity in the 20th century. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans; and others are concentrated in the food chain. It is necessary to balance agricultural needs with environmental and health issues when using insecticides.

Fig.6 Pesticide

There are some kinds of insecticide, such as DDT (dichloro-diphenyl-trichloroethane) that already banned because it is dangerous for living creatures. Farmer use insecticide to kill mosquitoes, grasshoppers, etc. These insects can harm the plant. The usage of insecticide is dangerous if it used excessively. It can damage the health, especially the farmer that using it.
Classes of agricultural insecticide
The classification of insecticides is done in several different ways:Systemic insecticides are incorporated by treated plants. Insects ingest the insecticide while feeding on the plants.
• Contact insecticides are toxic to insects brought into direct contact. They most often applied through aerosol distribution.
• Natural insecticides, such as nicotine and pyrethrum, are made by plants as defences against insects.
• Inorganic insecticides are manufactured with metals and include arsenates copper- and fluorine compounds, which are now seldom used, and sulfur, which is commonly used.
• Organic insecticides are synthetic chemicals which comprise the largest numbers of pesticides available for use today.
• Mode of action -- how the pesticide kills or inactivates a pest -- is another way of classifying insecticides. Mode of action is important in predicting whether an insecticide will be toxic to unrelated species such as fish, birds and mammals.
F. The Effect of Chemicals and Its Prevention
The danger of using chemicals excessively is environmental pollution, such as land, water, and air pollution. How can a chemical endanger the environment? Observe our surroundings. People usually throw garbage to bodies of water such as rivers, lakes, or sea. While washing clothes usually people directly release the waste water that contained detergent to drainage system so it pollutes the water. This pollutant prevents sunlight to penetrate the water. Water creatures are endangered by this.
Fertilizer and pesticide that is used excessively also can cause water pollution. The remains of fertilizers that enter the water system can make algae to thrive. These algae will cover the water surface. This occurrence is called eutrophication. The algae that covered the water surface can also prevent the sunlight from penetrating the water. As a result water plants can not perform photosynthesis, and they die. Dead plants will be decomposed. This decomposition need oxygen, as a result the oxygen content of the water will be lowered. Fish and water animals can not breathe in an oxygen lack environment, they will die.













Fig. 7 Eutrophication

The remains of pesticide such as DDT can also endanger the water system. It will kill plankton. Plankton that survive this (contain DDT in their body), will be eaten by small fish that in turn will be eaten by bigger fish. These fish will also contain DDT, the bigger the fish, the larger amount of DDT it contained. Human that eats this fish will also contaminated by this DDT. It can harm the health.
So how we can reduce the negative effect of excessive use of chemical? There are some points that we need to know.
1. Use chemicals in appropriate amount according to our need.
For example to kill a cockroach we need only spray this animal once or twice with insecticide.
2. Use chemicals that is degradable so it will not pollute the environment
3. Always pay attention to safety standards while using chemicals
4. Recycling the products that contain chemicals