Dish soap is a fairly modern invention, with the production of liquid dish soap beginning in the 1930s and ’40s. As they began to be manufactured at an industrial scale, they quickly nudged out many of the other cleaning agents that people were using earlier such as sand, wood ash, cow dung ash, brick or bone dust and alkaline salts such as cooking soda. Even today, it is a common practice in rural India to use sand and coconut fibre to scrub dishes clean.
So what does it take to clean dishes effectively?
We clean dirty dishes to get rid of grease and leftover bits of food that could decay and host all sorts of bacteria. Many of the foods we eat are rich in oil and animals fats and protein which are not water-soluble. If you run a greasy plate underwater, you will find the water flowing off the plate. This is because water and oil don’t mix. So, you need a substance that brings water and oil together and makes them easy to wash off.
This is where dish soap comes in. Dishwashing soap or liquids are a combination of water-repellent (hydrophobic) and water-loving (hydrophilic) components. The hydrophobic components repel water but draw the molecules of oil and grease. The hydrophilic components are attracted to the water and repel the fats.
When you scrub a dirty bowl with soap, the hydrophobic ends of the soap molecules stick to the oil molecules. When you turn on the tap, the hydrophilic ends of the soap molecules bond with the water molecules. Thus, each molecule of soap has stuck to a molecule of oil and water, creating tiny droplets that are now water-soluble. When you scrub the bowl and agitate it under flowing water or with a scrubbing action, the suspended particles are carried off the surface of the bowl.
Modern dishwasher liquids also contain surfactants or surface-active agents whose main task is to change the property of water. They reduce the surface tension of water and make it easier to spread. In short, it makes water wetter. Surfactants are foaming agents that also help in cleaning by loosening bits of oil and food from the dish’s surface and making them easier to wash off.
The dishes you use also make a difference in how much elbow grease is needed to clean them. Plastic dishes are the hardest to clean since plastic holds on to fats and oil. Glass and metal are easiest while Teflon-coated dishes are the easiest to clean since nothing sticks to them.
What do common dish wash liquids contain?
Most dishwashing liquids today contain synthetic chemical ingredients that could pose significant health risks. This is of concern in India where most dishwashing is done by hand. One of the most commonly used ingredients in liquid dish soap includes Sodium Lauryl Sulphate (SLS) which is used to cut through grease. When SLS is absorbed by the skin cells, it can lead to rash and allergic reactions.
Triclosan – Triclosan was first used as a pesticide in 1969, but since the 90s it began to be used in household and hygiene products because of its ability to prevent the growth of bacteria and fungus. This makes it a common ingredient in antibacterial products such as hand wash, dishwashing soaps and liquids, cosmetics, mouthwash and toothpaste. In 2019, following a US FDA ban on triclosan in consumer products, product companies in India too began to wake up to dangers and slowly reduce the usage of triclosan from soap and toothpaste.
However, there continues to be very little information about the use of triclosan in products and the only way to ascertain its presence is by reading product labels. However, there is mounting evidence to suggest that continued exposure to triclosan can interfere with muscle functions and also alter hormone regulation. Triclosan is most commonly transferred into the body through inhalation, ingestion and absorption through the skin. Triclosan’s health impacts include skin irritation, hormone disruption, allergies and asthma, altered thyroid hormone metabolism and tumour development.
Its harmful effects don’t end there. When it enters the environment through drains and sewage treatment plants, triclosan accumulates in lakes and rivers where it damages aquatic plants and animals. It has also been found to enter the food chain through contaminated water.
Phosphates – Phosphate makes dishes cleaner but can also cause eutrophication of water bodies when they become receptacles of domestic wastewater.
Formaldehyde – This is used as an antibacterial agent and preservative. It is widely used in detergents, dish wash liquids and cosmetics since it is cheap and widely available. Formaldehyde is known to be toxic for humans and causes irritation of eyes and skin infection such as dermatitis and eczema especially among those with daily contact with these cleaning agents.
Fragrance – Does your dishwash promise to lend your dishes the scent of a ‘spring garden’ or of ‘morning dew’? Many dishwashing liquids contain perfume which is a collection of non-specific ingredients that could be highly toxic. Synthetic fragrances have been known to cause allergic reactions, respiratory difficulty and skin trouble.
In addition to these, there are other harmful ingredients in dishwash liquids and gels including sodium hypochlorite (bleach), colourants, alcohols that are used in varying quantities and can have detrimental effects on human health.
Tips to Hand Wash Dishes Effectively
Most commercial dish wash soaps, liquids and gels are designed to produce a large volume of lather that we have all come to associate with a good clean. They also contain heavy-duty antibacterial agents that promise to disinfect our dishes but end up harming our health instead. In most of our homes where dishes are washed regularly, we do not need harsh chemical cleaners.
So how do you ensure you get a good clean on your dishes? Here’s how:
- Opt for a dishwash liquid that uses natural or plant-based surfactants – These ingredients make it easy to get that oil and grease off without doing a number on your health or that of the environment.
- Soak dishes in water before washing – Never let food particles and oil dry on your dishes. Not only does it make them harder to scrub, but it also wastes a lot more water than if you were to immediately rinse off utensils with water after cooking and eating.
- Use hot water for particularly stubborn grease – A lot of food that we eat can be easily washed off using cold water. But hot water is a good option to get rid of tough grease and to eliminate harmful bacteria.
- Minimise contact – If you are using a regular dishwash liquid, minimise contact with its toxic contents by wearing gloves or using a scrubbing brush with a handle.
If your dishwash liquid has any of the ingredients mentioned in this article, it is best to stay away from it or use it with caution. If the label does not list any ingredients, look for them on the manufacturer’s website. Your best bet, however, is to opt for a skin-friendly, eco-friendly alternative such as The Better Home dishwash liquid. It is made of plant-based surfactants and other ingredients that are non-toxic when ingested and pollution-free when washed into the environment. It loosens tough dirt and grease without being harsh on your skin.