Grade A LAF/DFB with Grade D/C Background

In our building, we have ceiling Laminar Air Flow units (Grade A in current SOP) with grade D background. Is it possible to revise the grade of ceiling LAF to the grade of the background? FYI, this ceiling LAF is used to dispense raw material before proceed to formulation of the finished product (medicinal). This area is being monitored once a week.

My rationale of this change of grade is because:
i) Personnel entering the ceiling LAF area with Grade D gown (One layer of gloves, bouffant cap, surgical mask, wearing clean (nonsterile) garment on top of street cloth). This also present human operators intervention.
ii) Introduction of nonsterile material inside the LAF area.
iii) No barrier/airlock between grade D and ceiling LAF area.

What is your opinion on this?

As per rule LAF must be placed in class B or 1000 area but in non-sterile manufacturing, product is also manufactured in grade D area therefore, it is acceptable because material being dispensed is also non sterile.