Well, after 3 months failsafe, my 8 year old son had a terrible reaction to what I suspect was 635. We gave in to Chargrill Charlie's, and within 12 hours, my son was coughing incessantly. He seemed ok to go to school (I didn't recognise what was happening), but I got a call from the school that he was having difficulty breathing. They gave him Ventolin (as per Asthma Attack protocol), and I brought him to the hospital as he was white, sweaty, shaky and very frightened. He later told me he had a blinding headache and felt like there were bubbles in his throat.

His headache dissipated over about 3 days which I treated with Panadol and Nurofen. He was quiet for several days, which is very unlike this energetic boy!  - Kathy

(Note that Nurofen is not failsafe; people who react to salicylates can be affected by it depending on dose)