Personally, i would say that if the employer was creating a dangerous working environment by forcing its employees to work beyond their means or in such a way that may lead to a dangerous occurance then it is definatley a H&S issue. It is the employers responsibility to ensure a safe working environment for all of its staff, if this is breached they are at fault and can result in court/fines. Its just the case of if the employee(s) do anything about it and bring it to their attention