Following a public outcry, ten Singaporean companies that manufacture paper products announced on Monday they do not source wood from five firms in Indonesia suspected of contributing to the haze.
Greenpeace says the fires, mostly from peatland, kill roughly 110,000 people a year in the region through associated conditions.
Indonesia has deployed 20,000 security forces police to water bomb the fields and use chemicals to artificially induce rainfall. It also says it has investigated companies and ordered four to suspend operations.