NUS undergraduate Regina Vanda (right) and UWCSEA student Gauri Shukla started a petition asking two companies to use sustainable cooking oil.

When Gauri Shukla visited Sumatra, Indonesia, in 2016, she saw first-hand how forests were being slash and burned to make way for oil palm plantations.

The Singapore permanent resident, who was 13 years old then, was devastated to see forests burning and piles of logs being removed by cranes.

It made her realise how much the environment was abused.

That's why Gauri, now 15, and Regina Vanda, 20, launched an online petition last year to get food companies to use environmentally-friendly oil.

Not only did it garner more than 8,000 signatures within four months, two companies - Old Chang Kee and Polar Puffs & Cakes - even responded to their petition to say they used sustainable oil.

Gauri and Regina met last year through a non-governmental organisation, People's Movement to Stop Haze (PM.Haze).

They approached more than 20 local food companies to ask if they were using Roundtable on Sustainable Palm Oil (RSPO)-certified oil, which is palm oil from sustainable sources. The pair told The New Paper most did not respond.

RSPO was established in 2004 to promote the use of sustainable oil palm products.

With PM.Haze's help, they identified Old Chang Kee and Polar Puffs & Cakes as possibly not using RSPO-certified cooking oil.

So, in October, the girls started an online petition asking the two companies to use RSPO-certified oil.

Gauri, a student at United World College of South East Asia (UWCSEA), said: "Their curry puffs are popular in Singapore and this was a ground-up approach to engage the company."

Regina, a year-one student at Yale NUS College, added: "We chose to approach local companies because we believed it is possible to get them to start using sustainable ingredients."

When the petition started, Old Chang Kee's marketing communications manager, Ms Ng Bee Lin, said the company was looking into sourcing oil that was RSPO-certified.

On Feb 2, the girls were surprised to receive an e-mail from Old Chang Kee, which said:"Our RSPO-accredited oil supplier has inserted the RSPO certification on our cooking oil tins."

Polar Puffs & Cakes also released a statement on its website in October saying it used healthy oil. Its spokesman said vegetable oil accounted for less than 0.6 per cent of its ingredients because its products are baked with butter and not fried with oil.

The statement added: "We also wish to assure our customers that our vegetable oils currently used are from sustainable sources (RSPO certified)."

This isn't the first time that Gauri has tried to make a difference through sustainable oils.

In 2015, she managed to get her school canteen to change to sustainably-sourced oil.

UWCSEA told TNP that its kitchens switched to using canola oil for all on-site cooking.

Sodexo, the school's food provider, made the change to physical certified sustainable palm oil at all its sites in Singapore in November 2016.

Mr Nathan Hunt, UWCSEA director of sustainability, said: "Gauri's work is especially commendable as it is an example of a sustained commitment by a student to campaign for a solution by leading other students over a number of years."

Regina said: "Sometimes, we need to rock the boat to get the change we want.

"A petition may not be the most pleasant approach but it was necessary to show people there is capacity for advocacy in Singapore."

Gauri added: "You don't have to wait until you're older to make a change. You just need to have the right mindset."