In the latest development in the 18-month battle between child safety advocates and landlords over a lead abatement bill, Councilwoman Blondell Reynolds Brown on Thursday amended the legislation to make it more palatable to property owners.

The amendment, which Council passed unanimously, would increase the amount of time between lead safety recertifications from three to four years.

“What good is a lead safe certification from four years ago if your child is playing on the floor and getting poisoned today?” Jana Curtis, whose daughter was poisoned by lead from soil in their backyard, said. “Our kids can’t wait any longer.”

Lead poisoning in children can lead to lower IQs and cause behavioral problems. Tainted by lead smelters in its industrial past, the city has historically failed to protect children from lead hazards in paint, dust, and soil.

The bill has been delayed several times as Reynolds Brown tinkered with it to address concerns from landlords and safety advocates.

According to the Philadelphia Department of Health, 62% of children living in rental housing as of 2017 had been exposed to toxic levels of lead.

Reynolds Brown first tried to tackle the lead-poisoning issue in 2011, with a requirement that the city certify properties built before 1978 where children 6 or younger live as “lead safe,” with the toxic metal eradicated or contained. It became law.

According to health department data, there are 16 ZIP codes — in nine of the 10 Council districts — where more than 10% of children screened have elevated blood levels.

Reynolds Brown decided to expand the 2011 ordinance to all rental housing, in part, because there was no protection for children who spend time with relatives in homes that aren’t their primary residences.

George Gould, a lawyer at Community Legal Services, noted that the bill originally required recertification every two years and was previously amended to three years, a compromise the safety advocates accepted begrudgingly.

“In four years, there can be serious deterioration of paint, and kids can get poisoned,” Gould said. “They said, ‘Well, it’s a compromise,’ but our view is you can’t compromise children’s health.”

Reynolds Brown said the four-year recertification period is similar to standards in other cities.

The proposed bill also includes provisions to prevent landlords from making tenants pay for the lead tests, which cost from $70 to $150, Reynolds Brown said.

Councilman Allan Domb said that while he supports parts of the bill, he has concerns it would not apply to unlicensed rental units.

“They’re our biggest violators," he said. "I just want to make sure we aren’t penalizing those who are doing the right thing.”