What is a negative air environment and why is it important?

MRS containment area

Performing disaster restoration work, as in other construction activities, can create a good bit of debris including dust and odor.

A containment area that creates a slight vacuum pressure within the containment may need to be constructed in order to prevent dust and other airborne particulates from escaping into other areas of the structure. The industry calls this creating a “negative air environment”. The goal of a negative air environment is to have air rush into the containment (as opposed to air rushing out of the containment) whenever a door is opened or other containment breach occurs (leaks, etc.). The action of air rushing into the containment effectively prevents dust and other particulates from escaping the containment area. Note that the need for an effective negative air environment is especially acute in medical (immunosuppressed patient & sterilization concerns) and other “clean” facilities.

A negative air containment system is first built by creating an enclosed “near air tight” space using existing walls, ceilings, and plastic sheeting where needed. Specialized air scrubbers equipped with HEPA filtration systems are then installed to exhaust the containment air to the outdoors or into an exhaust system within the building.
To ensure that a vacuum is present within the containment area, a device called a manometer is typically used. Its function is to indicate the presence of a vacuum in the containment. For many medical and other clean environments the amount of vacuum pressure (typically expressed in inches of water column) must be continuously measured, maintained (above a defined minimum value), recorded over time, and monitored with visual and audible alarms if the vacuum drops below the minimum value defined by the facility.

Massaro Restoration, an Infection Control Risk Assessment (ICRA) certified response team, utilizes digital differential pressure monitoring manometers that continuously display the vacuum pressure readings, record them over time, and will activate visual & auditory alarms if the vacuum pressure drops below the established minimum value.


Article by Franco Tavella, Business Development Executive

Hospitals and Construction can Coexist.


Have you ever had your house remodeled? Or spent time on a construction site? Or simply rearranged furniture in a room? Probably so, and you probably remember how dirty and dusty you and the area became. Now imagine these activities in a hospital setting where your loved one is recovering from a surgery or illness.

It’s not hard to imagine that without proper dust and dirt containment precautions, patients can easily be exposed to microbe carrying dust and dirt (yes, microbes use dust particles as flying-carpets as their primary means to get around). According to the Centers for Disease Control and Prevention (CDC) one out of 25 hospital patients have an infection related to in-hospital care. By simple hand washing and other basic procedures by the hospital staff and visitors, 95% of these infections can be prevented. The remaining 5% of the infections are caused by environmental conditions such as maintenance and construction activities. Hospitals and other medical facilities have realized the need to develop formalized procedures and patient risk classifications to reduce construction/maintenance related infections. These procedures and patient risk classifications have evolved into an industry certification called ICRA (Infection Control Risk Infection).

ICRA defines a Construction Risk Assessment for hospital work, which is addressed proactively within a construction bid or prior to the beginning of the job (through the use of the Infection Control Construction Permit). Patient risks and the types of construction activities are evaluated to determine the severity condition of the potentially affected patients verses the scope of the construction activities to be performed. The patient risk groups and types of construction activities are categorized within the ICRA matrix, which was developed to give a healthcare and construction professional an objective means by which to determine, amongst other construction byproducts (noise, vibration, etc.), the degree of dust/dirt containment needed to protect the patients. Once this is known, the task of setting up the appropriate containment system is straightforward and patients are left to recover, unexposed and safe.

All of Massaro Corporation’s superintendents, project managers, and project engineers are either ICRA 8-hour or 24-hour certified. Now, we are pleased to announce that everyone on the Massaro Restoration Services team has earned ICRA Certification as well.

Tavella_FrancoArticle by Franco Tavella, Project Manager



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