Hi, kerosene is by no means safe and even if your child has vomited, he still needs to kept under observation in hospital for at least 48 hours. The prime reason behind this is that kerosene can cause injury
to lungs if aspirated and lead to breathing problems. An XRAY chest should be done to rule out lung involvement.
If your child remains free of symptoms for the next 48 hours, food and drinks can be given. Meanwhile watchout for further episodes of vomitting and breathing difficulties. Ideally the child should be put under prophylactic antibiotics and antacids.
Wishing your child speedy recovery.