Facing criticism for selling garments made at a Bangladesh factory where 112 workers died in a fire last November, Wal-Mart Stores told its worldwide suppliers Tuesday that it was adopting tougher rules on fire safety at its contractors and would have “zero tolerance” for suppliers that used unauthorized subcontractors.

At least two suppliers were using the Tazreen Fashions factory in Bangladesh to produce garments for Wal-Mart in the weeks before the fire there. After the fatal blaze, Wal-Mart said those suppliers had used the factory without its knowledge after it had stopped authorizing production there. It did not say why. Wal-Mart said it had ended its relationship with those two suppliers.

In a letter sent to its suppliers on Tuesday, Wal-Mart said they must “fully and accurately disclose” in advance any factories they or any of their subcontractors plan to use. Under the policy, suppliers will be subject to termination even if an undisclosed factory is used “without the supplier’s knowledge” by anyone in the supplier’s supply chain. David Schilling, a program director at the Interfaith Center for Corporate Responsibility, praised the move, saying, “It’s an important step toward increased transparency and accountability of suppliers.”

Wal-Mart also announced tougher requirements on fire safety, saying “facilities found to have fire safety-related violations must initiate corrective actions immediately.” The company said that the repairs must be completed no later than 30 days after the violations were identified.