Of the 74 members in the Sigma Phi Epsilon fraternity involved in the investigation, 45 others were placed on probation, officials said.
"The university takes a very strong stance toward any form of hazing," university spokesman Tim Lynch said.
The fraternity was investigated for an incident at a March initiation ceremony where 14 students were blindfolded and driven to the high desert for a ceremony attended by 130 fraternity members and alumni.
The blindfolded students were positioned around a large bonfire and as their blindfolds were removed, gasoline was poured onto the fire for dramatic effect.
Some gasoline splashed onto a student, who suffered second-degree burns to his arms, legs and chest, officials said.
Fraternity members either couldn't be reached for comment or declined comment Tuesday.
The entire incident is considered hazing, but the accident that injured the student brought the hazing to light, Lynch said.
The university was notified of the incident May 28.
The national headquarters of the fraternity in Richmond, Va., suspended the Cal Poly Pomona chapter for four years, university officials said.
Representatives with the national chapter could not be reached for comment Tuesday.
The university played no role in the Sigma Phi Epsilon national headquarter's decision, Lynch said.
While the university's police department conducted an investigation, the Los Angeles County District Attorney's Office decided not to file criminal charges, officials said.
"The victim did not desire to pursue charges on this," Lynch said.
The student suspensions last two quarters. After that the nine students may be readmitted to the university, Lynch said.
Those on probation can't be involved in leadership at the school, run for office or join another fraternity while on probation, Lynch said. Those probation periods range from one quarter to two years, based on student involvement in the hazing, Lynch said.
"Students (on probation) must focus strictly on academics," Lynch said.
In a written statement, Vice President of Student Affairs Doug Freer said normal Greek activities at the school are positive.
"The Sigma Phi Epsilon case is an aberration and not reflective of my experience working for many years with our Greek community," Freer said.
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