Silfab Solar Chemical Spill Forces Elementary School Closure in York County, SC

A Solar Panel Factory, an Elementary School, and a Chemical Spill That Should Never Have Happened

If you live in the Charlotte metro area, you may have already heard about a solar panel manufacturing plant in York County, South Carolina that has been making headlines for all the wrong reasons. If you haven't — you need to.

Silfab Solar operates a large-scale solar panel manufacturing facility at 7149 Logistics Lane in York County, just south of the North Carolina border near Fort Mill. The plant sits just yards from Flint Hill Elementary School. And in March 2026, things went very wrong.

What Happened

According to public records obtained through FOIA requests and reported by Charlotte Stories, York County confirmed that 1,530 gallons of potassium hydroxide spilled into a retention pond that directly borders the elementary school. This happened while school was in session and children were playing near the fence line.

Days later, a multi-week hydrofluoric acid leak was discovered. Flint Hill Elementary was forced to close for two days. In response to the contamination, Silfab reportedly pumped roughly 300,000 gallons of liquid from the retention ponds for off-site disposal over a single weekend.

The Fort Mill School Board passed a formal resolution on March 10, 2026, calling on Governor McMaster, the state legislature, Attorney General Alan Wilson, and York County Council to permanently limit the facility to non-hazardous assembly processes and remove all hazardous chemicals from the site.

The Full Chemical Inventory

This is not a small operation with a few cleaning solutions on a shelf. The Silfab facility's own hazardous materials list (obtained through public records and labeled "Exhibit F: Tenant List of Hazardous Materials") reveals a staggering range of industrial chemicals stored, dispensed, and used on site, many of them just yards from where children go to school every day.

Here is what is listed on the facility's chemical use and storage requirements document:

Hydrofluoric acid (HF) — semiconductor grade. This is one of the most acutely dangerous industrial chemicals in existence. Unlike other acids, HF penetrates skin and tissue rapidly and can cause systemic fluoride poisoning, cardiac arrhythmia, and death — even from relatively small skin exposures. The facility stores 15,850 gallons of it.

Hydrochloric acid (HCl) — semiconductor grade. A highly corrosive acid that produces toxic fumes and causes severe burns to skin, eyes, and the respiratory tract.

Potassium hydroxide (KOH) — listed at 45% concentration and also as a dilute solution. This is the chemical that spilled — 1,530 gallons of it — into the retention pond bordering the school. It is a strong caustic base that causes severe chemical burns on contact.

Hydrogen peroxide (H2O2) — semiconductor grade, 30% or higher concentration. At industrial concentrations, hydrogen peroxide is a powerful oxidizer that can cause burns and is reactive with many other chemicals on this list.

Silane (SiH4) — 26,456 pounds. Silane is pyrophoric, meaning it ignites spontaneously on contact with air. It is also explosive. The inventory notes it is stored in an outdoor tank inside a bunker with concrete walls on three sides.

Ammonia (NH3) — stored cryogenically. Ammonia is toxic by inhalation and corrosive to the respiratory system. It is listed in the inventory as requiring corrosive gas room storage.

Nitrous oxide (N2O) — an oxidizer gas that accelerates combustion.

Trimethylaluminum (TMA) — a pyrophoric organometallic compound that ignites on contact with air and reacts violently with water.

Phosphorus oxychloride (POCl3) — a highly toxic and corrosive liquid that releases hydrochloric acid fumes on contact with moisture.

Boron trichloride (BCl3) — a toxic gas that reacts with moisture to form hydrochloric acid. Stored in bottles and cylinders inside the production building or in a centralized system.

Methane (CH4) — high purity, stored in a flammable gas room. A separate supply of methane or liquefied petroleum gas (LPG) for civil use is stored in an outdoor bunker.

Isopropyl alcohol (IPA) — stored in an indoor tank. A flammable solvent.

Sodium hydroxide (NaOH) — another strong caustic base, similar in hazard profile to potassium hydroxide.

Oxygen — high purity (99.999%), stored in an outdoor tank in a bunker, required to be at least 20 meters from the building.

Nitrogen — high purity liquid nitrogen used in multiple process steps, also stored in outdoor tanks in bunkers at least 20 meters from the building.

The inventory also lists additional chemicals used for water treatment and exhaust scrubbing, including ferric chloride (FeCl3), sulfuric acid (H2SO4), and carbonyldiamine (urea, used for NOx emissions treatment). A separate section notes that phosphine (PH3), carbon dioxide (CO2), and hydrogen (H2) were "under discussion, depending on the process selection" — meaning the chemical footprint of this facility could grow even further.

Workers Have Been Getting Sick

The chemical hazards at this facility are not theoretical. Dispatch records show repeated 911 calls from inside the plant for serious medical emergencies. A 25-year-old woman was reported vomiting blood on March 28, 2026. A 23-year-old man had trouble breathing on March 26. A worker suffered seizures on February 4. Additional calls involved chest pain, high blood pressure, and cardiac symptoms. According to Charlotte Stories, these incidents have occurred at a rate unmatched by comparable solar manufacturing facilities anywhere in the country.

How Did This Get Approved

This is where the story gets even more troubling. In May 2024, York County's Board of Zoning Appeals ruled unanimously — 5-0 — that solar panel manufacturing is not a permitted use in the Light Industrial zoning district where Silfab operates. Under York County's own zoning code, any use not expressly listed in the use tables is prohibited.

Despite that ruling, public records show that county staff continued issuing permits for the facility's build-out, including permits for chemical storage buildings, a wastewater treatment plant, and a central energy plant. A Certificate of Occupancy was issued on February 13, 2026, without zoning compliance. Internal emails suggest that approval dates on civil plans were back-dated to make it appear that valid permits existed before the BZA ruling.

York County Council Chairwoman Christi Cox and County Manager Josh Edwards have faced growing criticism for their roles in the process. Fellow council members have twice formally requested that the Silfab matter be placed on a council agenda — requests that were reportedly ignored, in apparent violation of York County Code § 30.04(b), which requires deferred agenda items to be placed on a future meeting upon request of two council members.

Why This Matters

I write a lot on this site about what we put in and on our bodies, understanding what's in our food, our water, our supplements, the products we bring into our homes. But sometimes the threat to your health isn't something you can opt out of at the grocery store. Sometimes it's 15,850 gallons of hydrofluoric acid stored next to a playground.

The families near this facility did not choose to live next to a chemical-intensive manufacturing plant. The children at Flint Hill Elementary did not consent to being exposed to industrial spills. And based on the public record, the local officials who were supposed to protect them chose not to enforce their own laws.

If you live in the Fort Mill or south Charlotte area, stay informed. Talk to your neighbors. Show up to council meetings. The Charlotte Stories investigation linked below contains the full timeline, internal emails, and supporting documents obtained through FOIA.

Source: Charlotte Stories — "Christi Cox and Josh Edwards Ignored the Law to Force Silfab's Toxic Factory Next to Kids"