In a risk assessment for any science experimental report, you usually list out the hazards, then briefly describe why it is a hazard, and list out the appropriate measure(s) to minimise/prevent that hazard, for example, if you were dealing with a substance that releases toxic fumes, for example, the risk description is intoxication by inhalation and a measure that could minimise/prevent this hazard is to conduct the experiment in a fume cupboard... hope this helps-it might be helpful to do your risk assessment in a table format if there are multiple risks