Is it safe to use a slow cooker on high all day?
Based on 1 peer-reviewed studykitchen
Verdict: Use Caution
Better than low all day if the insert is lead-free. High hits proper food safety temps faster.
What's actually in it
Slow cooker inserts are ceramic. Hours of hot, acidic cooking can extract trace metals from low-quality glazes. Top brands use lead-free ceramic; older or imported slow cookers may not.
What the research says
A 2025 study in J Hazard Mater tracked lead and cadmium leaching from ceramics with hot, acidic contents.
Use a modern lead-free slow cooker or an Instant Pot with stainless steel insert. Either handles acidic recipes without concern.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Migration kinetics of cadmium and lead from ceramic mugs. | J Hazard Mater | 2025 |
What to use instead
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