Anyone else concerned about pupils diluting 2M nitric acid? CLEAPSS advised me hydrochloric would be safer, but the response from my phone call to OCR was not very helpful which was basically - "it works at 0.5M and less" (it hadn't great when I tried it!). "Other schools have used 2M without a problem"!! and "So can I use hydrochloric?" "No, definitely not". Have any other schools done this one yet? (I have been deliberately vague to avoid giving anything away to pupils).