Seattle Mariners’ T-Mobile Park Hits a Homerun with GBAC® STAR Facility Accreditation


The Seattle Mariners have called T-Mobile Park home since July 19, 1999. With stunning views of the downtown waterfront and skyline and sunsets over Puget Sound and the Olympic Mountains, the venue is undoubtedly a great place to watch baseball. T-Mobile Park was even one of five ballparks included in the American Institute of Architects 150th Anniversary “favorite buildings” list.

The COVID-19 pandemic presented many challenges for professional sports stadiums and ballparks. T-Mobile Park had to navigate a shutdown at the outset of the global health crisis, the safe return of players, coaches, and staff members for games without crowds, and then eventually a smooth transition to games with fans in attendance.

“Fans need to have confidence that they’ll be visiting a clean, safe, and welcoming ballpark. This is even more important during a global pandemic,” said Rebecca Hale, Senior Director of Public Information, Seattle Mariners. “It is our responsibility as operators of a public facility to give our guests confidence in our health and safety protocols.”


T-Mobile Park partners with ABM, a leading facility management provider, to develop and execute cleaning and sanitation protocols. ABM is guided by an Expert Advisory Council composed of internal and external experts in infectious disease and industrial hygiene. The company’s proprietary EnhancedClean™ and EnhancedFacility™ programs for surface disinfection and indoor air quality helped T-Mobile Park build trust among employees, visitors, and the public.

As the pandemic progressed, the Mariners learned about GBAC STAR™ Facility Accreditation from the Global Biorisk Advisory Council™ (GBAC), a Division of ISSA. The accreditation for facilities of all types and sizes launched in 2020 to facilitate outbreak prevention, response, and recovery. Today, thousands of facilities around the world have earned the accreditation, including many sports venues, airports, convention centers, museums, and more.

“GBAC STAR is the industry standard. It was clear to us that in order to instill confidence among fans, employees, players, and public health authorities, we needed to have accreditation to validate our cleaning, disinfection, and infection prevention protocols and procedures,” added Hale.

Upon achieving GBAC STAR accreditation, the Mariners communicated the designation to fans via news releases, earned media events, website updates, and in-park messages during games.


With GBAC STAR accreditation, the Mariners have:

Institutionalized roles, responsibilities, and protocols. The accreditation process helped the Mariners roll out its Plan-Do-Check-Act (PDCA) program and structure key roles, responsibilities, and cleaning and disinfecting protocols for the ballpark. It has also enabled the organization to uphold accountability for the frequency and quality of work performed, documentation, and training. “GBAC STAR accreditation has been instrumental in driving continuous improvement and supporting our planning around disinfection of high-touch surfaces, accessibility of hand sanitizer stations, and more,” said Hale.

Solidified credibility among local public health and government authorities. Assuring local public health and government authorities that T-Mobile Park is safe is crucial. Without their approval, it would not have been possible to welcome fans back. GBAC STAR allowed T-Mobile Park to clearly communicate its cleaning, disinfection, and infection prevention programs to these organizations. The ballpark then followed a phased reopening that started with strict limits on attendance, progressed to vaccinated-only sections, and then returned to full capacity.

Instilled confidence among fans. Having third-party validation of T-Mobile Park’s cleaning, disinfection, and infection prevention practices gives fans confidence that their wellbeing is being prioritized. In fan surveys, the Mariners have consistently collected feedback about the high level of cleanliness of T-Mobile Park and the fact that it comforts visitors.

“In the constantly changing landscape created by the pandemic, GBAC STAR has helped us successfully adapt and allowed fans to enjoy their time at the ballpark,” added Hale.