The chaotic scene which had much of the Fenway/Kenmore arae shut down Tuesday evening was determined to be a makeshift lab for fish oils. 

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City inspectors responded to a complaint and found several 55-gallon drums as well as 5-gallon buckets containing unknown chemicals in the basement of the Fenway Market at 76 Kilmarnock Street. 

Hazmat teams, BPD, Boston Fire Department and the FBI Joint Terrorism Task Force swarmed the area. Nearby buildings were evacuated and a large portion of the area was cordoned off as officials worked to identify the chemicals. Officials found acids and Hydrogen Chloride among other chemicals, which they say were improperly stored. 

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It turns out that the owner of the Fenway Market was letting a friend use the basement as a lab to produce fish oils. The owner will be cited, but no criminal charges have been filed. 

After officials determined that the chemicals were not drug related or explosive, they escalated the situation and allowed people to return to their buildings at about 9:45 p.m. 

Clean Harbors crews were in the basement cleaning up the chemicals on Wednesday morning.