Solution : https://service.sap.com/sap/support/notes/414724 (SAP Service marketplace login required)
Key words : 
prerequisites causefunction module cbih_lb16_ip_existence_check sets export parameter e_flg_error, additional key words ehs27bsp01ihindustrial hygiene, environment parameter qty_person_check, input parameter i_persgrp, amount dialog box, required entry field, safetyrisk assessmentamountsperson groupqty_person_checkl_qty_person_checkcbih_lb16_ip_existence_check, form routine l_qty_person_check, attached correction instruction, risk assessment - amountsfor
Related Notes : 
       
| 395100 | Error in conversion report for person group | 
| 394519 | Installation of SAP EH&S 2.7B/4.5B | 
| 393855 | Installing SAP EH&S 2.7B/4.6C | 
| 392841 | Installation of SAP EH&S 2.7B/4.6B | 
| 391318 | EH&S 2.7B corrections: Support Package 01 |