The city has met a federal deadline to remove light fixtures containing toxins known as PCBs from public schools.
The EPA says doing so will protect children and staff members at nearly 900 school buildings from potentially cancerous chemicals.
Removing these lights will also boost energy efficiency by 30 to 50 percent.
The city originally said it would need until the end of 2021, and the Bloomberg administration tried to get a lawsuit over the removal timeline dismissed. But a judge refused, and the city agreed to speed up the timetable.