HOUSTON — A company says the air has been monitored following a leak last week in an ammonia product supply line in rural Southeast Texas.

Alison Jahn, spokeswoman for Houston-based Ascend Performance Materials, said Sunday that the flow of ammonia was turned off after the leak Thursday. Ascend, which owns the supply line, said in a statement that the leak occurred in an undeveloped, publicly inaccessible area of Brazoria County.

The company says the air is at safe levels.

Jahn says the company suggested residents of three farmhouses evacuate out of caution in case ammonia levels got too high. She says it’s advised they remain out of their homes until the repair is complete.

Jahn says a section of road blocked off as the air was monitored should reopen by Sunday night.