Cleanliness Requirements for Different Operating Rooms in Hospitals

It is common for people to picture Operating Rooms as clean, sterile and bright, but in real life, the requirements for cleanliness depend on what type of surgery is scheduled. If the area where surgery is done is not clean, it may put patients at risk, lower the success of the operation and affect their recovery. Thus, knowing how Operating Room cleanliness standards vary depending on the type of surgery is very significant.

Why is Operating Room Cleanliness so important?

One of the greatest risks during surgery is infection. Airborne particles, bacteria, or contaminants on surgical instruments can all lead to post-operative infections. To minimise infection rates, hospitals typically design operating rooms as Hospital Operating Theatre-grade clean spaces, using air purification, temperature and humidity control, and personnel management to ensure a safe surgical environment.

In some high-standard Surgery Operation Theatres, the number of dust particles per cubic metre in the air is strictly controlled. The more complex and high-risk the surgery, the higher the environmental requirements.

Classification of cleanliness levels for different operating rooms

In fact, the classification of Operating Rooms within hospitals is highly detailed, and not all surgeries are performed in the same environment.

• General operating theatres: Typically used for routine surgeries such as appendectomies and caesarean sections, these theatres have moderate cleanliness requirements, typically meeting ISO 7 or ISO 8 standards.

• Orthopaedic and joint replacement surgeries: Due to the involvement of joint manipulation and the implantation of metallic foreign bodies, these procedures carry higher infection risks. Such surgeries must be performed in operating theatres meeting ISO 5 or ISO 6 standards to ensure air cleanliness and environmental stability.

• Cardiac and neurosurgical procedures: Such as coronary artery bypass grafting and brain surgery, which demand extremely high cleanliness standards. These are typically performed in ISO 5 or higher-grade Hospital Operating Theatres to minimise the number of particles and bacteria in the air.

How do Operating Rooms maintain high cleanliness standards?

A standard Surgery Operation Theatre relies on a comprehensive air purification and management system:

• High-efficiency air filtration (HEPA): Capable of filtering out over 99.97% of airborne particles.

• Reasonable air exchange rate: Through frequent air replacement, continuously diluting and expelling contaminated air.

• Positive pressure design: Ensuring external air cannot flow back into the operating theatre.

• Standardised personnel procedures: Surgical staff must strictly wear sterile surgical gowns, masks, and hats before entering, with controlled access frequency and movement routes.

These meticulous measures are implemented to achieve professional Cleanroom Cleanliness standards, ensuring that every surgery is conducted in a safe and clean environment.

In short, Operating Rooms are cleaner than they look. Since different surgical procedures have different levels of risk, hospitals evenly assign topsurgery theaters to these surgeries and enforce strict control over the air system, the operating environment and staff to ensure safe and secure operations. Clean facilities are necessary for minor and major surgeries alike.