Your report should be according to SMART principles:
Sensible
Measurable
Achievable
Realistic
Time Bound
Above all, it should be sensible and persuade management to act upon its recommendations.
It is a report and should therefore be in report format, not a letter or memo or even an email! Avoid humourous vignettes such as: from: S. Afety MIOSH RSP or to: I. M. Self, MD and bar
It is not a list of hazards such as you would have created during your inspection and you should avoid repetition (there will often be numerous examples of the same hazards).
Measurable does not mean giving a risk ranking score, but should give some idea of the risk quantum. High, medium, low - is quite acceptable.
Achievable acknowledges cost-benefit analysis. Some risk reduction measures may be desirable but they could be simply too costly and resource could be better deployed – this is what risk assessment is all about.
Realistic reiterates this. It is not realistic to expect everything to be put right at once, so prioritization is important. If management can see the elements of an action plan to improve safety then they are more likely to act upon the recommendations.
Time bound. It is helpful to suggest timings because it supports the idea of an action plan. Not everything can be done at once, after all.
The report should not be unduly long just a basic introduction in which the general state of the plant is described. Acknowledge both good and bad features (there is nothing more off-putting than unmitigated gloom!).
The body of the report should be a series of headings followed by descriptions of the main items. Don’t try to be too detailed or the reader will be in danger of “can’t see the wood for the trees” syndrome and your message will be lost. And it should not be too long – 6 to 10 paragraphs would be typical in a report of this kind. At this stage indicate priorities and acknowledge costs