Floor openings without proper guarding, workers will be exposed to FALLS which are the largest cause of accidental injury and death in construction industry. Avoiding such hazards may seem like common sense, but a moment of distraction around an uncovered floor opening can end in disaster. About 40% of serious injuries mostly in building construction are due to falls from a certain level to another.
Floor openings or holes should be barricaded with solid physical barriers to keep workers out. Install guardrails is the best solution. In situations where guardrails can't be installed, the next best option is to cover the openings or holes. Ensure that the cover must be completely cover the opening, securely fastened, capable of supporting at least a 150 kilo load that may be encountered on the worksite and labelled "Floor Opening, Do Not Remove" or "Danger! Opening - Do Not Remove! Do Not Load!
If you must work on or near an unprotected opening it is a requirement that you have to wear safety harness securely fastened/fixed to a suitable anchor point.
Stick to the Permit System and must inform to the competent person or safety officer for that particular area prior to removal of any covers.
Best Practice (Actual done at site) show below:
MAKE IT HAPPEN......BE SAFE!