Home

Appendix I

Types of Respirators. The following is a description of different types of respirators. Please contact DES to help you evaluate the respirator that best fits your needs.

Commonly Used Respirators (Air Purifying)

• Disposable Dust masks are worn over the nose and mouth to protect the respiratory system from certain nuisance dusts, mists, etc. They can only provide protection against particular contaminants as specified by the manufacturer (e.g., general dust, fiberglass, etc.). These dust masks cannot be fit tested, and are generally single use. They are not recognized as respiratory protection and may not be worn if a potential for overexposure exists. They are not included in the University's Respiratory Protection Program.

• Half-Face Respirators with interchangeable filter cartridges can protect the respiratory system from hazardous dusts, fumes, mists, etc. They can only provide protection against certain contaminants up to limited concentrations specified by the manufacturer for the particular cartridge type used (e.g., toluene, acetone). These generally operate under negative pressure within the respirator which is created by the wearer's breathing through the filter cartridges. As the protection is only gained if there is a proper seal of the respirator face piece, this type requires fit testing prior to respirator assignment and a fit check prior to each use. This respirator can only be worn if the wearer participates in the UM respiratory protection program.

• Full-Face Respirators operate under the same principle and requirements as the half-face type, however, they offer a better facepiece fit and also protect the wearer's eyes from particularly irritating gases or vapors.

• Full-face, helmet or hood type powered air purifying respirators (PAPRs) operate under positive pressure inside the facepiece using a battery operated motor blower assembly to force air through a filter cartridge into the wearer's breathing zone. Use of these respirators is also subject to the manufacturers' guidelines and enrollment in the UM respiratory protection program.

Less Commonly Used Types Respirators (Air Supplying)

• Air-Line Respirators supply clean air through a small diameter hose from a compressor or compressed air cylinders. The wearer must be attached to the hose at all times, which limits mobility. Use of these respirators is subject to the manufacturers' guidelines and enrollment in the UM respiratory protection program.

• Self-Contained Breathing Apparatus (SCBA) respirators supply clean air from a compressed air tank carried on the back of the wearer. These types of respirators are highly mobile and are used primarily for emergency response or rescue work, since only a limited amount of air can be supplied by a single tank, generally 20-60 minutes. Units must be thoroughly inspected on a monthly basis and written records must be kept of all inspections, operator training, etc. Use of these respirators is subject to the manufacturer's guidelines and enrollment in the UM respiratory protection program.

Appendix II

Glove Chemical Resistance Guide (1)

(1)The data for Silver ShieldTM, VitonTM, Butyl and Nitrile gloves were provided by Siebe North Inc, Charleston, SC; information on Neoprene and Polyvinyl Chloride (PVC) gloves were supplied by Pioneer Industrial Products, Williard, OH.

(2)In Kerosene

E=Excellent; G=Good; F=Fair; P=Poor; ND=None detected; ID=Insufficient Data; D=Degradation; BT=Breakthrough, amount of elapsed time after initial exposure before the chemical can be analytically detected on the inside surface of the glove; PR=Permeation Rate is expressed in mg/m2/sec. PR can be used for estimating glove thickness required; for a given material, thicker is more resistant.

Note: Silver Shield gloves may be worn as liners under other glove types to enhance protection.

Table used by permission of Van Nostrand Reinhold publishing.

We would greatly appreciate your feedback about this site.  RSS Feed Copyright © 2008 University of Maryland DES

UM Home | Directories | Search | Admissions | Calendar Maintained by Department of Environmental Safety Direct questions and comments to safety@umd.edu