(CNN) Bear repellent sent two dozen workers at an Amazon fulfillment center in New Jersey to hospitals on Wednesday after a machine punctured an aerosol canister of the spray, causing it to discharge toxic fumes inside the building, a town spokesman told CNN. 
 
 Employees reported difficulty breathing and burning sensations in their eyes and throat, said John Nalbone, a spokesman for Robbinsville Township, where the fulfillment center is located. 
 
 Emergency personnel responded to a morning 911 call that 54 workers at the facility were experiencing symptoms, Nalbone said. Twenty-four workers, including one in critical condition, were taken to hospitals, he said. 
 
 All affected workers either have been released or will leave the hospital by Thursday evening, Amazon spokeswoman Rachael Lighty said. 
 
 A preliminary investigation said the canister fell off a shelf, but Nalbone further clarified that an automated machine punctured a 9-ounce can of the bear repellent. 
 
 Read More ||||| Twenty-four Amazon workers in New Jersey have been hospitalized after a robot accidentally tore a can of bear repellent spray in a warehouse, officials said. 
 
 The two dozen workers were treated at five local hospitals, Robbinsville Township communications and public information officer John Nalbone told ABC News. One was in critical condition while 30 additional workers were treated at the scene. 
 
 All of the workers were expected to be released from the hospital within 24 hours, WABC reported Thursday. 
 
 The official investigation revealed "an automated machine accidentally punctured a 9-ounce bear repellent can, releasing concentrated Capsaican," Nalbone said. Capsaicin is the major ingredient in pepper spray. 
 
 The fulfillment center was given the all clear by Wednesday evening. 
 
 “ ” 'Amazon's automated robots put humans in life-threatening danger today' 
 
 “Today at our Robbinsville fulfillment center, a damaged aerosol can dispensed strong fumes in a contained area of the facility. The safety of our employees is our top priority, and as such, all employees in that area have been relocated to safe place and employees experiencing symptoms are being treated onsite. As a precaution, some employees have been transported to local hospitals for evaluation and treatment,” an Amazon spokeswoman told ABC News in a statement. 
 
 The company said safety of employees is always their top priority. 
 
 "All of the impacted employees have been or are expected to be released from hospital within the next 24 hours. The safety of our employees is always our top priority and a full investigation is already underway. We’d like to thank all of the first responders who helped with today’s incident,” Amazon said in a statement Wednesday night. 
 
 Bess Adler/Bloomberg via Getty Images FILE 
 
 "Robbinsville Fire Dept on scene at Amazon Warehouse on New Canton Way investigating 'fumes' that have several employees complaining of illness. Fire Dept is attempting to isolate the source. EMTs are triaging multiple patients. 7 ambulances and a medic currently assigned," the Robbinsville Fire Department tweeted at 6:05 a.m. on Wednesday. 
 
 Robbinsville Fire Dept on scene at Amazon Warehouse on New Canton Way investigating “fumes” that have several employees complaining of illness. Fire Dept is attempting to isolate the source. EMTs are triaging multiple patients. 7 ambulances and a medic currently assigned — Robbinsville Fire (@IAFFLocal3786) December 5, 2018 
 
 There is no threat to residents in the area and the fumes were confined to the fulfillment center's third floor south wing, Nalbone said earlier. The warehouse is approximately 1.3 million square feet and was ventilated. 
 
 Amazon employees are not unionized, but the Retail, Wholesale and Department Store Union issued a statement about the danger that robots pose to human workers. 
 
 "Amazon's automated robots put humans in life-threatening danger today, the effects of which could be catastrophic and the long-term effects for 80 plus workers are unknown," union president Stuart Appelbaum said in a statement. "The richest company in the world cannot continue to be let off the hook for putting hard working people's lives at risk. Our union will not back down until Amazon is held accountable for these and so many more dangerous labor practices." 
 
 ABC News' Briana Montalvo contributed to this report. ||||| UPDATE: OSHA investigates Amazon warehouse bear spray accident that left worker critical 
 
 A worker at an Amazon warehouse in New Jersey was in critical condition and another 54 required treatment after being exposed to bear repellent that discharged when a can was punctured by an automated machine Wednesday morning inside the building, officials said. 
 
 A total of 54 workers at the Robbinsville distribution center were exposed to the bear repellent experienced difficulty breathing and burning in the throat and eyes, officials said. They were triaged by first responders outside the building and required treatment, according to a Robbinsville spokesman John Nalbone. 
 
 Twenty-four of those workers were taken to five local hospitals, Nalbone said. 
 
 One worker was critical and was taken to Robert Wood Johnson University Hospital in Hamilton, but the employee’s condition improved as of 9:30 p.m. and they were expected to be released within 24 hours, according an Amazon spokeswoman. 
 
 “All of the impacted employees have been or are expected to be released from hospital within the next 24 hours," she said. "The safety of our employees is always our top priority and a full investigation is already underway. We’d like to thank all of the first responders who helped with today’s incident.” 
 
 Additional details on the other workers was not immediately available. 
 
 Around 8:45 a.m., an automated machine punctured a 9 oz. can of bear repellent containing a concentrated amount of capsaicin, an active component of chili peppers. It was confined to the third floor in the south end of the sprawling warehouse — which has hundreds of workers during a normal shift — and did not require a complete evacuation, Nalbone said. 
 
 Amazon confirmed the damaged can dispersed strong fumes in the contained area of the facility, and said there is an ongoing investigation. 
 
 “The safety of our employees is our top priority, and as such, all employees in that area have been relocated to a safe place and employees experiencing symptoms are being treated onsite,” the company spokeswoman said Tuesday morning. “As a precaution, some employees have been transported to local hospitals for evaluation and treatment.” 
 
 The warehouse was cleared for re-entry around 1 p.m. by the West Windsor Health Department, but an official will revisit the building before Thursday morning as a precaution. 
 
 Editor’s Note: This story has been updated to reflect additional information on the number of workers requiring treatment and the severity of the injuries. 
 
 Sophie Nieto-Munoz may be reached at snietomunoz@njadvancemedia.com. Follow her at @snietomunoz. Find NJ.com on Facebook. 
 
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– Amazon sells everything, including bear spray, a fact that made for a pretty rough workday for some employees at an Amazon fulfillment center in Robbinsville, NJ. ABC News reports bear repellent spray was accidentally released on the third floor of the 1.3 million-square foot facility, sending 24 workers to five area hospitals "as a precaution," per Amazon. NJ.com reports one worker remains in critical condition. Another 30 workers were treated on-site after the 9-ounce bottle, which CNN likens to pepper spray, was accidentally punctured by an automated machine. Workers subsequently experienced breathing troubles and burning in the eyes and throat. (A freak accident created a toxic gas cloud at a Tampa pool.)