Had the opportunity to attend a demo on how to make dishwashing bar soap in Bandar Baru Bangi today. By using used cooking oil (UCO) as one of the substances, we are actually helping to save the environment. Without having proper knowledge of disposing the oil, naturally we would tend to discard the oil into the kitchen sinks, onto the soil etc.
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(*Session was held by Dr Hanisah Azhari of UKM.)
1. The ingredients : used cooking oil, water and lye (sodium hydroxide, NaOH)
2. On NaOH. Need to take precautions when using this chemical, such as wearing gloves and goggles to those who don’t wear spectacles.
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3. The ‘recipe’... Note: Different types of soap require different recipes. This proces uses the
cold press method. More on cold press.
4. NaOH (dalam botol putih. Dalam bentuk small crystal). Essential oil dalam botol gelap, kecil. Minyak masak dlm botol sebelah kiri gambar.
5. Weigh the water in a container eg a plastic jug. Then weigh NaOH in a small container. Next weigh the UCO. Note: Wash with lots of water, the affected area if your skin is exposed yo NaOH.
(Note: this pic is taken from
A video)
6. The next step will require precautionary measures and needs to be done at an open place (eg near the window, door or outdoor). Wear gloves and/or goggles.
a) Put in NaOH little by little into the water. (Do not put water into NaOH). Stir slowly until NaOH crystals dissolved. (Note: the reaction will give out heat (exothermic reaction) , so it will be a bit hot. White vapour will also be released. Do not directly inhale it. )
b) Once the NaOH solution is cool, pour it into the UCO. Stir.
Note: Do NOT use the apparatus used in this procedure for other purposes. Only wash apparatus used after 2,3 days.
8. Let the soap cool for a day. Then cut it into smaller bars. These smaller soap bars need to be aired for about a month before they can be used. This step is called ‘cure’.
For more on cure
9. Samples of cured dish washing soap bars given to us.
Note: It is adviseable to attend a soap-making workshop and watch related videos if you are interested in this.