A Merced County judge denied a request by Livingston High School chemistry teacher Japhia Smith Huhndorf to remove the monitoring bracelet from her ankle Thursday.
Huhndorf, 34, was arrested in May on six felony counts for allegedly keeping the explosive compound nitroglycerin in her classroom and helping her students inhale chloroform.
Those charges include child endangerment and possession of explosives in a school or public setting.
She has pleaded not guilty. Her preliminary hearing is set for Dec. 15-16.
Huhndorf was released from jail after posting her $100,000 bail in September and has worn the monitoring device since. Her attorney, Paul Fromson, requested Judge Marc Garcia to remove the monitoring bracelet, saying his client has abided by the court's terms. Garcia denied the request.
Huhndorf was arrested after Livingston police reported finding a vial of 4 milliliters of nitroglycerin in her chemistry lab.
That incident came after she had been arrested on suspicion of helping three students inhale chloroform.
The discovery prompted school officials to evacuate the campus of about 1,100 students and end classes for the day.
The Merced Police Department's bomb squad responded to dispose of the nitroglycerin.