Streets around Notre Dame Cathedral have been sealed off as workers prepare to decontaminate the streets from high-levels of lead after April’s blaze.
Hundreds of tons of toxic lead melted during the fire, which destroyed the landmark’s iconic spire.
High fences blocked Parisians and tourists from several streets and a bridge around the cathedral on Tuesday.
The culture ministry said workers plan to use two decontamination techniques.
One involves spreading a gel on public benches, street lights and other fixtures to absorb the lead, letting it dry for several days before removing it.
Another method will feature high pressure water jets with chemical agents.
The clean-up work inside Notre Dame, suspended last month for safety reasons, will resume next week.
Last month, an environmental group filed a lawsuit over health threats from the lead, claiming local officials should have immediately imposed protective measures.
Inhaling or ingesting lead can lead to a range of health problems, including damage to the nervous and reproductive system.
Flames consumed Notre Dame on the evening of April 15.
The inferno decimated the roof of the Paris landmark, though firefighters saved the main bell towers and outer walls from collapse before bringing the blaze under control.
French President Emmanuel Macron has set a goal of rebuilding it in just five years and is determined to have it ready in time for the 2024 Olympics, which will be held in the French capital.
One billion euros was raised to fund the restoration.
Around 400 firefighters battled the fire into the night and tried to salvage artwork and other priceless pieces stored in the 12th-century cathedral.
Some of the cathedral's most precious objects, including a relic purported to be the crown of thorns worn by Jesus Christ on the cross, were rescued.
Prosecutors said they have no grounds to believe that the fire was the result of criminal action but they were probing the possibility of negligence.