The mistake is blamed for 28 children and two adults at the day care center accidentally ingesting a mixture of bleach and water.
It happened at 10:53 a.m. Thursday at The Growing Tree II Learning Center on 5th Street.
The worker, on her first day on the job, mistakenly used the re-purposed gallon milk container and did not realize there was a label on it saying "mixed bleach and water."
All the children were treated and released from the hospital.
The day care was cleared to reopen Friday morning. Parents were given a letter explaining what happened, and there will be information sessions about the incident for them Friday evening from 5 to 6 p.m.
The staff at the day care will also participate in a re-training session.