Jane Turner intervened in a heated argument between a group of children near a school to help end it.
However, during the dispute a parent of one of the children reported hearing her say: “Go and play with your own little white friends, you’re nothing but white trash.”
After she was reported to police, Mrs Turner initially denied using the phrase but later admitted she had said “white trash” and has since apologised.
Mrs Turner was working at Moseley School, a specialist language college in Birmingham, when the incident took place almost 20 miles away.
She was convicted at Halesowen Magistrates Court of an offence of using racially threatening words or behaviour likely to cause harassment or distress.
She was made subject of a community order for one year with a requirement to carry out 80 hours of unpaid work and was ordered to pay compensation of £50.
The General Teaching Council also investigated and yesterday announced its conclusions, criticising her for “unacceptable professional conduct” but stopping short of suspending her from teaching over the incident which took place in April 2009.
The GTC committee reported: “Mrs Turner witnessed a dispute between a group of young people near school premises, more than 20 miles from the school in which Mrs Turner taught.
“Mrs Turner intervened in the dispute and in the heat of the moment was observed by a parent of one of the other children saying: “Go and play with your own little white friends, you’re nothing but white trash.”
“Mrs Turner accepts that making a comment like this amounts to unprofessional conduct.
“Mrs Turner accepts that her words on this occasion may have been perceived as racist and that it is entirely inappropriate for a Registered Teacher to make such a comment.
“The Committee agrees. A registered teacher must demonstrate respect for diversity and promote equality. Conviction of an offence of this type brings the profession into disrepute.
“Although the offence was not committed in the vicinity of the school where Mrs Turner was teaching at that time, her behaviour set a very bad example for the schoolchildren who were present at the time.”
The GTC committee said that it took into account that she was of previous good character and that, while she was not at first willing to accept what she had done, she was now “genuinely sorry”.
It added that she told the police that, at the time of the incident, she was worried about the health of a relation.
The committee also noted that her head teacher at the time had not found it necessary to take any further action within the school.
The findings say that in other circumstances a much more severe sanction would have been appropriate, but that having regard to all the mitigating circumstances of the case, the committee considers that the appropriate and proportionate response was a reprimand, which will remain on Mrs Turner’s professional registration for two years.
Mrs Turner has a right of appeal to the High Court within 28 days.