CONYERS, Ga. — Conyers, a city of roughly 17,000, has been evacuated and surrounding Rockdale County, with a population of nearly 100,000, is under shelter-in-place guidance continuing into the early morning hours of Monday after a fire at a BioLab facility and resulting chemical plume.

Rockdale County provided updated guidance at 3:20 a.m. Monday morning.

RELATED: Conyers chemical fire: Videos, photos show smoke cast ominous shadow over community

Here is the basic critical information as of 3:20 a.m.:

Evacuation: This was put into place for virtually the entire city of Conyers, a zone between Sigman Road and I-20. See an evacuation zone map here.

Shelter-in-place: This was advised for the whole county through midnight on Sunday, and the early-morning update from the Rockdale County government has extended it into Monday with no given timetable for when it might end. Those sheltering in place are advised that "the best practice is to turn the air conditioning off and keep windows and doors shut."

What's in the air: The presence of chlorine has been confirmed by federal EPA and state EPD testing, Rockdale County said. What, if any, other chemicals might be involved has not been detailed.

What direction is the plume going?: Unclear as of 3:20 a.m., with the Rockdale release describing an "unpredictable path and wind direction."

Shelter locations for those affected:

The Rockdale County Government posted about shelter locations. Below is a list:

2484 Bruce St. Lithonia, 30058

218 Scout Road, Covington, 30016

3375 E Fairview Road SW, Stockbridge, 30281

DeKalb County has opened a recreation center to assist residents displaced.

The American Red Cross is accepting evacuees at Lucious Sanders Recreation Center, 2484 Bruce Street, Lithonia, beginning at 9:30 p.m. on Sunday.

DeKalb County Emergency Management has provided 200 cots.

Interstate-20 remains closed: This is in effect for both eastbound and westbound directions between Turner Hill Road and Almon Road.

Hotlines: People are asked not to call 911 for non-emergency situations. They are directed to the county EMA hotline at 770-278-8300 or Rockdale County Sheriff's Office non-emergency line at 770-278-8200.

Newton County Schools closed: Newton County is directly southeast of Rockdale. The schools in Rockdale County are on fall break starting today. Also, Georgia Piedmont Technical College's Newton and Rockdale campuses will be closed until further notice, a spokesperson said.

Hospital situation: Officials said Piedmont Rockdale Hospital had evacuated some patients and that the hospital is on diversion. They asked anyone with an emergency situation to go to a hospital in a neighboring county.

In a statement, a spokesperson for BioLab said representatives are "actively responding" to the situation. The spokesperson said employees "are accounted for with no injuries reported." BioLab said it has a team is on the scene, working with first responders and local authorities to assess and contain the situation.

"As always, the safety of our community remains our top priority," the statement read.

11Alive will provide additional updates throughout the day on the situation:

Conyers chemical plume after BioLab fire; evacuations & shelter-in-place guidance | Latest updates

7:30 a.m. | In the Facebook post by Rockdale County notifying everyone that I-20 is open again, many comments are wondering things like if this means people can go home -- one commenter said her husband has not been able to get home and is without his insulin -- whether people can go to work, what the air quality results are and more.

So far, no official clarity on these questions.

7:25 a.m. | Rockdale County alerted just before 7 a.m. that I-20 has reopened on both sides.

5:15 a.m. | Traffic cameras show that at least some traffic on I-20 East is currently open approaching the area where Sigman Road turns into North Salem Road.

5:00 a.m. | See the full Rockdale County release from 3:20 a.m. below:

More on Conyers chemical plume | What happened?

County officials said that around 5 a.m., a sprinkler head malfunctioned, causing a mixture with a "water-reactive chemical," which in turn started a small fire on the building's roof. That fire was contained and put out, but reignited around noon. The fire was again put out around 3:30 in the afternoon.

The continuing chemical plume emanating from the site is, officials said, the result of water continuing to react with chemicals.

Rockdale officials stated this is the third incident at the facility in seven years involving products mixing with water and causing a chemical reaction.

What is BioLab?

According to its website, BioLab is based in Lawrenceville and is the "swimming pool and spa water care division of KIK Consumer Products."

The company makes brands, including BioGuard and SpaGuard, that it says "pioneered computerized water testing and the 3-step system for pool and spa care."

RELATED: BioLab in Conyers had similar chemical fire, smoke plume situation in 2004 | Here's what happened

A similar fire and resulting chemical plume happened at a BioLab building in Conyers in 2004 -- it's unclear if the current situation is at the exact same site or perhaps a newer building.

BioLab back in 2004 was owned by Chemtura, a conglomerate that went into bankruptcy and was later acquired by a German company called Lanxess. BioLab is now owned by KIK Consumer Products, according to its website, in a sale from Chemtura a few years before that Chemtura was acquired by Lanxess.

Here are some ingredient lists for BioGuard products:

Ingredient list for Spa Guard product: