I think it depends on your reasoning. You have responded to his request in a reasonable and proportionate way. Why do you need to see his risk assessment? There may be some legitimate reasons like: -you need to satisfy your insurers that companies working on your premises have the appropriate H&S measures in place -one of the employees has had an accident on your premises and you want to make sure that they are working safely and have had the risks identified with controls put in place -you have observed them working unsafely and want to make sure the company have the required H&S in place But then again reasons which are unacceptable could be: -you're just being nosey -you are trying to inconvenience them -you need to do a risk assessment but are not competent to do one I'm not saying that any of those are your reasons by the way, just giving some examples! So what is the reason you are asking for it?

You have completed a risk assessment at his request and put in some corrective actions to reduce the risk to his employees from the work they are undertaking on your site. Presumably you would have sent a copy to him? I think it is more than justified, therefore, that you ask for a copy of his working procedures to give you a complete package of information for your risk assessment file, otherwise you only have half a story on which to base your risk rating. Remember, until such time as you add people to your environment, you only actually have a hazard not a risk, so I think it is absolutely imperative that this information is sought.