Dry decontamination is a method of removing contaminants (such as chemicals, biological particles, or other liquids, gasses, or solids) without the need to use water or other liquids. Decontamination is an essential duty of hazmat responders as it protects victims from harmful reactions to the contaminants. [1]
Dry decontamination is a relatively recent method of decontamination and is especially useful in cold weather conditions, [2] or when water is scarce or difficult to transport. Dry decontamination reduces the size and manpower requirements of the decontamination line and eliminates the need to purchase excess equipment that becomes ineffective due to storage or infrequent use. [3]
Dry decontamination is usually performed after the removal of clothing and before a shower (when available). There are five different types of dry decontamination, each of which can be used in conjunction with others to remove up to 100% of all suspected contaminants: [4]
Scraping is a process of decontamination in which the bulk contaminant is removed from the victim or environment using a spatula, wooden tongue depressor, or other handheld implement. Scraping works best with viscous liquids and solids.
Absorbent materials are specifically made to absorb (or capture and contain) contaminants. Absorbent materials include FiberTect, [5] Reactive Skin Decontamination Lotion (RSDL), Fuller's earth, flour, baking soda, paper towels, etc., all of which absorb hazardous materials from the victim. After absorption is completed using an absorbent material and immediate danger has passed, the contaminated surface should be blotted with a wet paper towel. An absorbent material increases in volume when a contaminant is absorbed. [6]
The DEC'POL® Emergency Decontamination Mitt is a polyvalent device that incorporates superabsorbent material with active agents for the destruction of chemical and biological contamination. The mitt was developed and is produced in Lyon, France, by clothes and fabric manufacturer Ouvry SAS. [7] DEC'POL is available in cases of 20 mitts. [8]
FiberTect is a multi-layer nonwoven composite fabric that absorbs and adsorbs chemical, biological, and radiological contaminants. It is made of two layers of polyester with an inner layer of fibrous activated carbon. [5] The three layers are needle-punched to form a single fabric that allows the material to be structurally sound while creating void spaces for better absorption and adsorption. [4] FiberTect is available in wipes or mitts, which remove up to 90% of contaminants. [9]
RSDL (or Reactive Skin Decontamination Lotion) consists of an absorbent sponge applicator and a lotion that neutralizes toxic agents. RSDL removes or neutralizes chemical warfare agents, T-2 toxins, and pesticides.
Fuller's earth is any clay material that has the ability to absorb oil, grease, etc. without chemical treatment. It is also used for filtering, clarifying, decoloring, and as a filler in paint. It is used by the military and first responders to decontaminate clothing and equipment.
Adsorbent materials adhere to and encapsulate contaminants on various surfaces. Adsorbent materials do not increase in volume when a contaminant is absorbed. [4]
Vacuuming physically removes solid materials from victims and the contaminated environment. Vacuuming should only be done when the victim and all people in the vicinity are wearing respiratory protection and the usefulness of vacuuming can be limited by the availability of supplies, equipment, and electricity.
Pressurized air uses low-pressure air streams to remove solid, dry contaminants from equipment and the environment. As with vacuuming, the use of pressurized air should be limited to situations where all people in the contaminated area are wearing personal protective equipment (PPE). The use of pressurized air is often not recommended because there are many hazards associated with the method, including respiratory and skin damage. [4]
Dry decontamination reduces concerns associated with cold weather decontamination while also speeding up the decontamination process by allowing victims to self-decontaminate (or be decontaminated by a first responder with minimal cross-contamination). In addition, some contaminants are water-reactive and wet decontamination methods may only increase the potential hazards. [6]
The deployment of a dry decontamination system allows the victim to assist in his/her own decontamination. In addition, dry decontamination operations are expedited by allowing for the quick removal of contaminants from the victim's skin, reducing the amount of time a victim is in contact with the contamination (which therefore minimizes the potential harm caused).
When conducting decontamination in temperatures below 36 °F, dry decontamination can be an effective solution that prevents more casualties resulting from hypothermia. [1] Other sources recommend that wet decontamination be avoided in external temperatures of below 65 °F to avoid the adverse effects of cold shock. [4]
Wet decontamination lines require not only a water source, but occasionally electricity for deployment. As a rule, dry decontamination is faster both in deployment and clean-up as it does not require an immediate water supply, contaminated water collection basin, resources (like hoses, nozzles, shelters, and other large pieces of equipment), or a large number of personnel.
Large-scale decontamination often involves civilians who, unlike soldiers and responders, are not trained in decontamination methods. Currently, wet decontamination is most frequently used in large-scale decontamination efforts, during which civilians are directed by soldiers and responders to shower (usually with water and a detergent or bleach). Dry decontamination is proving to be a safer, more effective method of decontamination for large-scale incidents. [10] [11]
Sewerage is the infrastructure that conveys sewage or surface runoff using sewers. It encompasses components such as receiving drains, manholes, pumping stations, storm overflows, and screening chambers of the combined sewer or sanitary sewer. Sewerage ends at the entry to a sewage treatment plant or at the point of discharge into the environment. It is the system of pipes, chambers, manholes, etc. that conveys the sewage or storm water.
Silica gel is an amorphous and porous form of silicon dioxide (silica), consisting of an irregular tridimensional framework of alternating silicon and oxygen atoms with nanometer-scale voids and pores. The voids may contain water or some other liquids, or may be filled by gas or vacuum. In the last case, the material is properly called silica xerogel.
Cleaning is the process of removing unwanted substances, such as dirt, infectious agents, and other impurities, from an object or environment. Cleaning occurs in many different contexts, and uses many different methods. Several occupations are devoted to cleaning.
Environmental remediation deals with the removal of pollution or contaminants from environmental media such as soil, groundwater, sediment, or surface water. Remedial action is generally subject to an array of regulatory requirements, and may also be based on assessments of human health and ecological risks where no legislative standards exist, or where standards are advisory.
Human decontamination is the process of removing hazardous materials from the human body, including chemicals, radioactive substances, and infectious material.
A pulp mill is a manufacturing facility that converts wood chips or other plant fiber source into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or fully chemical methods. The finished product may be either bleached or non-bleached, depending on the customer requirements.
Carpet cleaning is performed to remove stains, dirt, and allergens from carpets. Common methods include hot water extraction, dry-cleaning, and vacuuming.
Overview
Groundwater remediation is the process that is used to treat polluted groundwater by removing the pollutants or converting them into harmless products. Groundwater is water present below the ground surface that saturates the pore space in the subsurface. Globally, between 25 per cent and 40 per cent of the world's drinking water is drawn from boreholes and dug wells. Groundwater is also used by farmers to irrigate crops and by industries to produce everyday goods. Most groundwater is clean, but groundwater can become polluted, or contaminated as a result of human activities or as a result of natural conditions.
Decontamination is the process of removing contaminants on an object or area, including chemicals, micro-organisms or radioactive substances. This may be achieved by chemical reaction, disinfection or physical removal. It refers to specific action taken to reduce the hazard posed by such contaminants, as opposed to general cleaning.
Spray-and-vac cleaning is a “no-touch” method – cleaning is accomplished without the need for workers to touch soiled surfaces with their hands – used in professional cleaning in which a pressurized, diluted cleaning solution is applied to soiled or contaminated surfaces.
A biogas upgrader is a facility that is used to concentrate the methane in biogas to natural gas standards. The system removes carbon dioxide, hydrogen sulphide, water and contaminants from the biogas. One technique for doing this uses amine gas treating. This purified biogas is also called biomethane. It can be used interchangeably with natural gas.
Oxygen plants are industrial systems designed to generate oxygen. They typically use air as a feedstock and separate it from other components of air using pressure swing adsorption or membrane separation techniques. Such plants are distinct from cryogenic separation plants which separate and capture all the components of air.
Dry carpet cleaning involves the use of specialized machines to clean carpets with recently developed chemical technologies that permit no-moisture or "very low moisture" (VLM) cleaning, resulting in carpet beautification, and removal of stains, dirt, grit, sand, and allergens. Clean carpets are recognized by manufacturers as being more visually pleasing, potentially longer-lasting and probably healthier than poorly maintained carpets.
Wet process engineering is one of the major streams in textile engineering which refers to the engineering of textile chemical processes and associated applied science. The other three streams in textile engineering are yarn engineering, fabric engineering, and apparel engineering. The processes of this stream are involved or carried out in an aqueous stage. Hence, it is called a wet process which usually covers pre-treatment, dyeing, printing, and finishing.
Air sparging, also known as in situ air stripping and in situ volatilization is an in situ remediation technique, used for the treatment of saturated soils and groundwater contaminated by volatile organic compounds (VOCs) like petroleum hydrocarbons which is a widespread problem for the ground water and soil health. The vapor extraction has manifested itself into becoming very successful and practical when it comes to disposing of VOCs. It was used as a new development when it came to saturated zone remediation when using air sparging. Being that the act of it was to inject a hydrocarbon-free gaseous medium into the ground where contamination was found. When it comes to situ air sparging it became an intricate phase process that was proven to be successful in Europe since the 1980s. Currently, there have been further development into bettering the engineering design and process of air sparging.
Hazmat diving is underwater diving in a known hazardous materials environment. The environment may be contaminated by hazardous materials, the diving medium may be inherently a hazardous material, or the environment in which the diving medium is situated may include hazardous materials with a significant risk of exposure to these materials to members of the diving team. Special precautions, equipment and procedures are associated with hazmat diving.
Oil regeneration - is extraction of contaminants from oil in order to restore its original properties to be used equally with fresh oils.
Diving equipment may be exposed to contamination in use and when this happens it must be decontaminated This is a particular issue for hazmat diving, but incidental contamination can occur in other environments. Personal diving equipment shared by more than one user requires disinfection before use. Shared use is common for expensive commercial diving equipment, and for rental recreational equipment, and some items such as demand valves, masks, helmets and snorkels which are worn over the face or held in the mouth are possible vectors for infection by a variety of pathogens. Diving suits are also likely to be contaminated, but less likely to transmit infection directly.