Differential pressure is the difference in air pressure between two locations within a system.
A room with higher pressure than its surroundings is said to have positive pressure.
A room with lower pressure than adjacent areas is said to have negative pressure.
Positive pressure areas keep particles out, while negative pressure areas prevent the escape of
potentially harmful substances.
The pressure differential is maintained according to the Standard ISO classes. ISO 14644-4
recommends a pressure differential from room to room of 5 to 20 Pascal.
According to WHO guidelines on HVAC system 10-15 of pascals.
Differential pressure is important in pharmaceutical environments.
𝐂𝗼𝗻𝘁𝗮𝗺𝗶𝗻𝗮𝘁𝗶𝗼𝗻 𝗖𝗼𝗻𝘁𝗿𝗼𝗹:Maintaining differential pressure helps prevent the entry of
contaminants, such as dust, bacteria, or viruses, into critical areas like cleanrooms or sterile
processing areas.
𝐏𝗿𝗼𝗱𝘂𝗰𝘁 𝗜𝗻𝘁𝗲𝗴𝗿𝗶𝘁𝘆: In pharmaceutical manufacturing, certain processes require specific
pressure differentials to ensure the integrity of products, such as preventing cross
contamination between different drug formulations or protecting sensitive materials from
exposure.
𝐒𝗮𝗳𝗲𝘁𝘆: Differential pressure is crucial for the safety of personnel working with hazardous
materials. Negative pressure areas can contain airborne pathogens or volatile substances,
minimizing the risk of exposure.
𝐑𝗲𝗴𝘂𝗹𝗮𝘁𝗼𝗿𝘆 𝗖𝗼𝗺𝗽𝗹𝗶𝗮𝗻𝗰𝗲: Many pharmaceutical facilities must adhere to strict regulations
and guidelines, such as Good Manufacturing Practices (GMP) and Good Laboratory Practices
(GLP). Proper differential pressure control is often a regulatory requirement.
Differential pressure is maintained between manufacturing and surrounding areas.
The aseptic area should always be highly pressurized than the non-aseptic area and air flow
should be always from the aseptic to non-aseptic area.
This pressure differential is maintained by HVAC system.
In tablet production area, pressure differential helps to prevent the cross-contamination.
The pressure unit, 𝗺𝗺𝘄𝗰, stands for millimeters per water column.