NO--a relatively small amount will NOT cause permanent harm; it will STING however. Best 1st-Aid: Irrigate the eye for at least 10-15 minutes with clean (filtered or bottled) water (cool temp.); then repeat AGAIN for 10-15 mins after a short break.
If child still has a lot of burning or stinging; or eye looks very RED; or he cannot see well (blurred vision), then DEFINITELY take him to an ER or Urgent Care Ctr today.
Hope this helps, and best wishes for your child's health...
To be honest, I have mixed feelings; I DO understand the strategy, and I'm sure it was an effective strategy; BUT--it needs to be exercised w/ care (to NOT get into the eyes or mouth). Reporting to CPS seems like an EXTREME measure, however. Perhaps there should have been a discussion first.
That's my opinion, anyway.
Best, -Dr. Steve (please hit *ACCEPT* as you read this; thanks)