U.S. flag

An official website of the United States government

Government Website

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Safely connect using HTTPS

Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Archived Content

In an effort to keep DHS.gov current, the archive contains outdated information that may not reflect current policy or programs.

NBACC Biosafety Level 4 Positive Pressure Protective Suits

Scientists or superheroes? These suits may not have capes, but they do protect Science and Technology Directorate researchers from diseases and pathogens that have no vaccine or treatment. These positive pressure, airtight suits are made of a rubbery material—chlorinated polyethylene—and are designed for the wearer to breathe filtered air. Exhaust valves help cool and protect researchers as they work, and HEPA filters and air lines ensure they are breathing clean air.

This graphic depicts the back and front of two different models of Positive Pressure Protective Suits worn by researchers and scientists at Department of Homeland Security (DHS) Science and Technology Directorate’s (S&T) National Biodefense Analysis and Countermeasures Center, or NBACC. Both suits are worn in a Biosecurity Level 4, or BS-4, environment. The first suit is the Sperian BSL-4 Positive Pressure Protective Suit. It is mostly white in color with a few orange accents, and the graphic points out the following features on the front view: Scrubs (sterilized and washed after every use); Hair bonnet for comfort (optional); Internal ventilation system with built-In HEPA filters; Valve that controls air pressure entering the suit; Internal bladder that distributes the air entering the suit; Outer protective gloves are attached to the suit on a hard wrist cuff (there are internal gloves attached to the scrubs for additional secondary protection); Gas tight zipper; and The suit could come with integral booties, welded boots, or safety boots attached depending on the use of the suit. (This feature is demonstrated on the front and back views) Features highlighted on the Sperian suit’s back view include: Built-in hooks to hang the suit for storage; PVC-coated polyester fabric for moisture-resistance and safety; Built-in Class D breathing air line; Tongue on the boot for easy dressing; and Two magnetic pressure exhaust valves on the back. The second suit shown (front and back views) is the Chemturion (Dover) BSL-4 Positive Pressure Protective Suit. This is mostly light blue in color, and the image depicts green boots. Features highlighted on the front view include: Scrubs (sterilized and washed after every use); Hair bonnet for comfort (optional); Internal ventilation system; Outer protective gloves are attached to the suit on a hard wrist cuff (there are internal gloves attached to the scrubs for additional secondary protection); Gas tight zipper; and An exhaust valve on each leg to provide protection and cooling. Features highlighted on the Chemturion suit’s back view include: Built-in hooks to hang the suit for storage; Two exhaust valves on the back to provide protection and cooling; Chlorinated Polyethylene suit for moisture-resistance and safety; HEPA filter; Built-in Class D breathing air line with pressure control valve; and The suit could come with integral booties, welded boots, or safety boots attached depending on the use of the suit.

Last Updated: 08/01/2024
Was this page helpful?
This page was not helpful because the content