Five members of a youth swim team were taken to hospitals this January after exposure to a corrosive acid at a Colorado community pool, fire officials said The exposure occurred January 20, at the Sundance Hills pool, in Greenwood Village, in the Denver metro-area, according to South Metro Fire Rescue (SMFR).

A 911 caller reported that “multiple members of a swim team were ‘experiencing medical symptoms’ after being exposed to muriatic acid,” fire officials said.

First responders arrived and found the swim team members had already evacuated the pool area.

There were no ongoing threats to the public after firefighters worked to contain the chemical spill, SMFR said.

Fire crews determined that the acid had dissipated into the pool water and “no longer posed a threat,” but the incident was serious enough to activate the hazardous materials team.

The five swim team members were transported to hospitals for assessment and care, though fire officials did not immediately release details about the severity of their conditions or whether they were admitted.

The Sundance Hills pool is owned and operated by the Sundance Hills Metropolitan District, which manages the community’s pool facility and related amenities.

District officials did not immediately return requests for comment on whether a review of procedures or safety protocols was underway following the incident.

Experts warn that exposure to pool chemicals — whether through accidental spills, improper mixing of incompatible chemicals (such as acid with chlorine compounds), or inadequate training — can lead to respiratory irritation, eye and skin burns, and other injuries. National safety guides emphasize the importance of proper storage and clear labeling of pool chemicals.

The U.S. Centers for Disease Control and Prevention and industry groups recommend regular training for pool operators, careful monitoring of chemical levels, and strict adherence to safety data sheets for all compounds used to maintain pool water quality.