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Remediation Technologies Screening Matrix, Version 4.0  
Chapter 15 Biofiltration (Vapor)
Table of Contents


15-2 Hazard Analysis

Principal unique hazards associated with vapor biofiltration include:

Physical Hazards Chemical Hazards Radiological Hazards Biological Hazards

a. Physical Hazards

(1) Description: Entering process vessels and tanks for activities such as inspection, repair, and maintenance is a confined-space entry. Hazards associated with entry into confined space include asphyxiation from the lack of oxygen, overexposure to toxic wastes and byproducts, and engulfment/entrapment by the filtration media.

Control: Use confined-space entry procedures for any entry activities. Wear appropriate personal protective equipment (PPE), including respiratory protective (e.g. an air-purifying respirator with organic vapor cartridges) or supplied air, as needed. Use the "buddy system" for such operations. CONTROL POINT: Operations, Maintenance

15-1 Typical Process for Biofiltration (Vapor)

(2) Description: Workers may be exposed to electrical hazards when working around biofilters. Permanent and temporary electrical equipment which is not ground-fault protected, and contacts water or other liquids, may cause electrocution.

Control: Verify that the hazardous area classifications, as defined in NFPA 70-500-1 through 500-10, are indicated on the drawings. All controls, wiring, and equipment should be in conformance with the requirements of EM 385-1-1, Section 11.G and NFPA 70 for the identified hazard areas. Equipment should be grounded and/or provided with ground fault interrupter circuit (GFIC) protection if required by EM 385-1-1, Section 11 or NFPA 70 requirements. Only trained and experienced workers should be permitted in the areas. CONTROL POINT: Design, Construction, Operations, Maintenance

(3) Description: Permanent or semi-permanent treatment buildings may present life safety hazards such as inadequate egress, fire suppression systems, and/or emergency lighting systems.

Control: Permanent and semi-permanent treatment system buildings should be constructed in accordance with ANSI 58.1: Minimum Design Loads for Buildings and Other Structures; the National Fire Code; the National Standard Plumbing Code; Life Safety Code; and the Uniform Building Code. Depending on where the project is located, the structures must also comply with either the Air Force Manuals on Air Force bases, the USACE Technical Manuals on Army installations, or Local Building Codes on Superfund, BRAC or FUDS project sites. CONTROL POINT: Design, Operations

b. Chemical Hazards

(1) Description: Biological activity of the biofilters may be enhanced with the addition of nutrients or other chemical agents. These agents may include nutrients (e.g. ammonia nitrate, urea) or other chemicals (e.g. hydrochloric acid, sodium bicarbonate). Workers may be exposed to these chemicals during their application. Acute overexposure symptoms may include irritation of the eyes, skin, and respiratory tracts.

Control: Precautions to help prevent worker overexposure include the use of personal protective equipment (e.g. an air-purifying respirator with organic vapor cartridges) during the application or blending processes, and design of mechanical addition systems which minimize exposure. CONTROL POINT: Design, Operations, Maintenance

(2) Description: Storage of the materials may cause fire or explosion if these materials are spilled and allowed to mingle with incompatible chemicals.

Control: Store incompatible materials separately or in secondary containment. Consult the manufacturer or the Material Safety Data Sheets for incompatibilities. CONTROL POINT: Design, Operations, Maintenance

c. Radiological Hazards



d. Biological Hazards

Description: Biofilters may expose workers to pathogenic microbes, especially during maintenance or repair activities where the reactor may need disassembly, or when workers are required to enter the biofiltration vessels. Inhalation of pathogenic microbes may cause allergic reactions or illness. During support media handling activities, workers' hands may be exposed to the microbes and result in accidental ingestion of pathogenic material.

Control: The amount of mist, and consequently the amount of exposure, may be controlled by installing partitions or barriers to contain the mist, and via use of HEPA(N100, R100, P100) filter-equipped air-purifying respirators. Skin exposure may be minimized with the use of personal protective equipment such as gloves (e.g. butyl rubber gloves) and chemically-resistant disposable coveralls, and by practicing good decontamination by thoroughly washing of hands and face before exiting the work area. CONTROL POINT: Design, Maintenance


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