New USC Study Shows Deadly Chemical Spill Risks Near Proposed Silfab Solar Facility
- silfabmove
- 2 days ago
- 4 min read
A newly released Phase 3 study conducted by the University of South Carolina’s Arnold School of Public Health confirms that a potential chemical release at the Silfab Solar facility in Fort Mill could result in life-threatening or deadly exposure for children attending Flint Hill Elementary School and Flint Hill Middle School, as well as for nearby neighborhoods, retirement communities, and day care facilities.
The independent assessment focused specifically on real-world health consequences for people living, working, and attending school near the facility. The study emphasizes that children are uniquely vulnerable during chemical exposure events due to their developing lungs, higher breathing rates, smaller body size, and limited ability to recognize danger or evacuate without assistance.
Modeling in the study shows that under certain conditions, hazardous plumes could travel well beyond the immediate industrial corridor, encompassing residential areas miles away, including communities such as Baxter Village and Tega Cay.
“These findings show that the consequences are not minor and they are not hypothetical,” said Andy Lytle, president of Citizens Alliance for Government Integrity (CAGI). “When emergency-response modeling shows the potential for life-threatening or deadly exposure well beyond a facility’s boundaries, the only responsible conclusion is that this facility does not belong next to schools and neighborhoods.”
What the USC Study Examined
Phase 1 and Phase 2, completed in May 2025, focused on how far hazardous chemicals could travel following an accidental release. Those phases established the geographic footprint of concern, with potential impact distances ranging from fractions of a mile to several miles depending on the chemical involved.
Phase 3 goes further by examining the intensity and severity of exposure within those affected areas. This phase used the ALOHA modeling program, a tool widely relied upon by fire departments, hazmat teams, emergency managers, and government agencies to plan for real-world chemical emergencies.
Five chemicals associated with the proposed Silfab facility were analyzed:
Anhydrous Ammonia
Silane
Hydrofluoric Acid
Hydrochloric Acid
Nitrous Oxide
Each chemical was modeled under multiple weather conditions, including daytime scenarios when school is in session and nighttime scenarios which were found to be more dangerous in every case. Nighttime scenarios were consistently more dangerous due to atmospheric stability, which allows hazardous plumes to travel farther and remain concentrated for longer periods.
The results are shown through color-coded maps:
Red zones indicate areas where exposure could cause permanent injury or death
Orange zones indicate serious, irreversible health impacts
Yellow zones indicate significant but recoverable health effects
The researchers also note that the modeling does not account for a domino effect caused by equipment failures, chemical interactions, transportation incidents, and/or intentional acts, meaning the projected impact zones represent conservative estimates rather than worst-case scenarios.
Chemical-Specific Findings
Anhydrous Ammonia
Anhydrous ammonia produced the largest and most concerning impact areas in the study.
Daytime conditions showed life-threatening or deadly effects extending up to 0.83 miles, with health effects reaching 4.6 miles
Nighttime scenarios showed life-threatening or deadly effects extending up to 2.1 miles, with health effects extending beyond 6 miles
These levels meet the definition of being immediately dangerous to life and health.
Silane
Silane releases also showed severe impacts extending well beyond the facility.
Daytime conditions produced life-threatening or deadly effects up to 1.1 miles
Nighttime scenarios extended that distance to 1.3 miles, with health effects reaching more than 2 miles
Hydrochloric Acid
Hydrochloric acid affected broad surrounding areas.
Daytime modeling showed life-threatening or deadly effects up to 0.29 miles, with health effects up to 2.2 miles
Nighttime scenarios extended health effects as far as 3.5 miles
Hydrofluoric Acid
Hydrofluoric acid is highly toxic even at lower concentrations.
Daytime scenarios showed life-threatening effects within 0.076 miles
Nighttime conditions extended health effects up to 2.3 miles
Nitrous Oxide
Nitrous oxide produced more localized but still serious impacts.
Life-threatening effects ranged from 0.23 to 0.26 miles
Health effects extended to approximately 1 mile
What This Means for Our Community
This assessment was conducted because prior zoning and permitting decisions did not include a comprehensive, independent evaluation of potential public health impacts from accidental chemical releases at this location.
The study demonstrates a real and significant risk to students, school staff, and residents if Silfab Solar becomes fully operational at this location.
The modeled impact areas include:
Flint Hill Elementary School
Flint Hill Middle School
21 additional schools
Nearby neighborhoods
Retirement communities
23 Day care facilities
The Bottom Line
The takeaway from Phase 3 of the USC study is clear. Silfab Solar is not located in a properly zoned area for the level of risk identified. The findings show that the risks identified are preventable and location-specific, meaning the potential for serious harm exists only because of where the facility is proposed to operate. The findings reinforce the need for York County Council to enforce the May 2024 decision of the Board of Zoning Appeals and require the facility to be relocated to a heavy industrial zoned area, away from schools, neighborhoods, retirement communities, and day care facilities.