Printer paper supplier Mukim Fine Papers has stopped buying from Asia Pulp and Paper (APP).
The local firm, which imports paper to distribute here, also halted supplies from two Indonesian firms it gets its paper from.
"We will sell the remaining stock and then stop taking from these companies," said its business development manager Ben Chua, 41. "The companies are still under investigation but judging from public sentiments, we want to signal to APP that we do not accept such actions."
He added: "We also want to signal to consumers that we are serious about the environment."
Products from APP and Indonesia make up 10 per cent of Mukim's stock. Most of its paper products are from Europe.
According to the Singapore Environment Council (SEC), the firm is one of seven which did not sign a SEC declaration stating their paper products here are free of raw materials from five other companies under investigation for their involvement in the haze.
Mr Chua said Mukim will sign it when all its APP stock has been sold - in about a month or two.
In a joint statement with the Consumers Association of Singapore (Case) yesterday, SEC listed 10 companies that had signed the declaration, out of the 17 they had contacted with paper products certified under the green label scheme administered by the council.
Late last month, the National Environment Agency (NEA) began legal action against five companies - Singapore-listed firm APP and four Indonesian firms - it believes are possible culprits behind the burning of forests in Indonesia that caused the haze.
Another company that did not sign the SEC declaration is NTUC FairPrice Co-operative. About 20 per cent of paper products the supermarket chain carries are sourced from APP through a distributor here.
"We assure that prompt and firm actions will be taken on any of our suppliers if they are found to be responsible for any unethical practices that contributes to the haze," said NTUC FairPrice's chief executive Seah Kian Peng, who added that the firm has approached APP to seek clarification on its practices.
Meanwhile, the chain will continue to carry APP's products.
Malaysian firm Malaysian Newsprint Industries, which also did not sign the form, said it was getting it vetted by the firm's legal team. Its technical support supervisor, Tan Kin Chyuan, said that the firm does not work with the firms being probed.
Tissue paper supplier Tipex declined comment. The remaining three firms could not be contacted.
Those that signed the form are required to tell SEC if they begin to do business with parties suspected to be responsible for the haze.
SEC's executive director, Edwin Seah, said the council will be approaching firms to ask why the form was not signed. "We will investigate, then decide if we need to revoke their green labels."
He added that the delay could be due to the firms making checks. "Supply chains can be very intricate. Firms can have many suppliers who farm out their processes to even smaller firms."
Case's president Lim Biow Chuan urged consumers to stop supporting companies who have not pledged to be socially responsible. "This will send a strong signal to the errant companies that consumers' goodwill should not be taken for granted," he said.
Shipping executive Ricky Chan, 53, who works in shipping, said that he will not be boycotting paper products not on SEC's list.
"The haze is a problem that is not easy to solve. Singapore is so small, the companies supply not just to us but also the whole world," said the father of two. "Even if I stop buying such things, it won't change anything."
But consumer Chan Chin Hee, 50, finds the list useful.
Said the businessman: "Now I can choose the companies that are not involved. The haze is really bad now; my throat is so sore. This is the only way I can express my anger."
Get MyPaper for more stories.