Disclaimer
only one type of record absolutely must be kept in a separate file apart from the regular personnel files: medical information (including FMLA and workers' compensation records) - that is because the Americans with Disabilities Act requires that any medical records pertaining to employees be kept in separate confidential medical files
still, it is a good idea to maintain other types of records in separate files as well:
I-9 records - keep these in a separate I-9 file because it will make it easier to defend against a national origin or citizenship discrimination claim if you can show that such information is available only to those with a need to know (in other words, that those who might have made an adverse job decision were not aware of the person's national origin or citizenship status) - also, if your I-9 records are ever audited, it would be better if the auditor only saw I-9 records, instead of all kinds of other records mixed in that might give rise to reports to other governmental agencies
safety records - for the same reason you would want an INS auditor to see only I-9 records in an I-9 audit, you want an OSHA auditor to see only OSHA-related records in an OSHA audit - this safety record file might also contain documentation relating to an employee's participation or involvement in an OSHA claim or investigation - limiting access to such documentation would make it easier to keep the information from influencing possible adverse decisions against the employee that in turn could result in retaliation claims under OSHA
grievance and investigation records - maintain a separate file for these records because they often contain embarrassing, confidential, or extremely private information about employees that could give rise to a defamation or invasion of privacy lawsuit if such facts were known and discussed by others within the company - also, making it known that investigation records will not be divulged may make it easier to persuade reluctant witnesses to give frank and honest answers in an investigation
the human resources department can develop a security access procedure for these various files - the company can keep an overview by cross-referencing in one file documents in another file - if a person who has access to one file wants to see another document in a separate file, he or she would have to have clearance under the file access procedure in order to do that
Texas law does not require an employer to allow an employee to access his or her personnel file (exception: public employees may request copies of their personnel file documents under the Public Information Act) - however, most companies allow supervised access and copying of contents at the employee's cost - a company should never place anything in a personnel file that it would be ashamed to show other people (such as 12 average jurors) - remember, anything in any file relating to an employee is discoverable in a claim or lawsuit filed by or on behalf of that employee!
For an example of a personnel files policy, click here.