Cleaning and disinfection of personal diving equipment

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. ^{[1] [2]}

Contents

• Contamination sources
• Pathogens likely to be found on personal diving equipment
• General cleaning
• Cleaning after use
• Disinfection before use
• Targeted disinfection
• Disinfection to prevent SARS-CoV-2 infection
• Pathogens associated with specific environments
• Specific equipment
• Targeted chemical decontamination
• See also
• References

The maintenance of personal diving equipment includes cleaning and inspection after use, repair or servicing when necessary or scheduled, and appropriate storage. A large part of this is washing off salt water to prevent it from drying on the equipment and leaving corrosive brine or abrasive salt deposits, which can cause accelerated deterioration of some materials and jamming of moving parts. The ultraviolet component of sunlight can also damage non-metallic components and equipment, and ozone produced by electrical equipment is known to adversely affect some materials, such as the latex seals on dry suits. Storage at high temperatures can also reduce the useful life of some materials. Most diving equipment will last better if stored in a cool, dry place out of direct sunlight.

When disinfecting diving equipment it is necessary to consider the effectiveness of the disinfectant on the expected or targeted pathogens, and the possible adverse effects on the equipment. Some highly effective methods for disinfection can damage the equipment, or cause accelerated degradation of components due to incompatibility with materials. Ultraviolet light - including sunshine, ozone and high temperatures are among these. Chlorinated water in swimming pools will also degrade some materials, but rinsing in fresh water after use will minimise the effect. ^[1]

Effective cleaning and sanitisation procedures are expected of service providers renting diving equipment to the public, and by commercial diving contractors in terms of occupational health and safety legislation, and codes of practice. ^{[3] [4]}

Contamination sources

Diving equipment may be contaminated by several types of materials from several classes of source.

Types of contamination include:

• Biological agents, including pathogens, irritants, and toxic organisms or parts thereof.
• Chemical materials, which may be hazardous to the user, or harmful to the equipment.
• Radioactive materials
• Mechanical contaminants, such as sand, which can danage or degrade performance of equipment, or cause discomfort or injury to the user.

Routes of contamination include:

• The diving environment, particularly in Hazmat diving, in which cases the likely contaminants will be known and plans will be in place to effectively deal with them, but sometimes also unexpected contaminants, which may be more difficult to manage.
• The user may contaminate some items of equipment during normal use, or by accident.
• During handling and storage, usually due to unexpected circumstances.

Pathogens likely to be found on personal diving equipment

• Pathogens from a contaminated environment.
• Pathogens transmitted in saliva, sputum, nasal mucus and vomit are possible contaminants of masks, demand valves, snorkels, helmets and buoyancy compensator inflation heads and interiors. These potentially include a wide range of viruses and bacteria, including rhinoviruses and coronaviruses. ^[1]
• Pathogens transmitted by contact with skin infections are possible contaminants of diving suits and diving suit accessories.
• Pathogens found in bodily discharges including urine and feces are possible contaminants of diving suits.

Pathogens which are known to contaminate bodies of water include: ^{[5] : Ch2}

• Bacteria, such as: ^{[5] : Ch2}
  • Escherichia coli  – Strains of E. coli that can cause disease
  • Salmonella spp.  – Genus of bacteria
  • Klebsiella pneumoniae  – Species of bacterium
  • Aeromonas hydrophila  – Species of heterotrophic, Gram-negative, bacterium
  • Vibrio vulnificus  – Species of pathogenic bacterium found in water
• Protozoans, such as: ^{[5] : Ch2}
  • Entamoeba histolytica  – Anaerobic parasitic protist
  • Giardia duodenalis  – Parasitic microorganism that causes giardiasis
  • Naegleria fowleri  – Species of free-living excavate form of protist
  • Acanthamoeba spp.  – Genus of protozoans
  • Pfiesteria piscicida  – Toxic dinoflagellate species
• Viruses

Pathogens which may be transmitted between sequential users of diving equipment:

• Bacteria:
• Viruses:
  • SARS-CoV-2  – Virus that causes COVID-19Pages displaying short descriptions of redirect targets

This section needs expansionwith: more pathogens. You can help by adding to it. (March 2021)

General cleaning

Cleaning to remove salt water, sand, mud, and other relatively harmless environmental contaminants is intended to reduce degradation of the equipment and improve comfort during the next use. In most cases soaking or rinsing in fresh water is sufficient, but detergents and occasionally scrubbing before rinsing can speed up the process. This basic cleaning may remove some pathogens and chemical contaminants, but it is not reliable for this purpose. This level of cleaning has traditionally been considered sufficient for equipment only used by one person in environments considered to be free of chemical and microbial health hazards.

Targeted disinfection

During periods of increased risk relating to a specific pathogen during an epidemic, or after diving in an area known as a high risk for a specific pathogen, disinfection procedures will target that pathogen.

During an epidemic, the first line of defence is for symptomatic people and people who have tested positive for the infection to refrain from diving, however in the early stages of some diseases it will not be apparent that the person is infectious, so it is prudent to take reasonably practicable preventative measures when the risk is assessed as significant.

Disinfection to prevent SARS-CoV-2 infection

This section needs to be updated. Please help update this article to reflect recent events or newly available information.(December 2022)

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes the COVID-19 disease is considered easier to kill than the closely related SARS-CoV-1, so in the absence of specific test results for SARS-CoV-2, methods for disinfection of SARS-CoV-1 are assumed to be effective. ^[6]

According to the World Health Organization, SARS-CoV-1 loses infectivity after 15 minutes at 56 °C (133 °F), Another study showed that SARS-CoV-1 remains stable between 4 °C (39 °F) and 37 °C (99 °F), and loses infectivity after 30 minutes at 56 °C (133 °F). (Duan et al 2003 in DANSA 2020) ^[7]

Divers Alert Network has estimated that a breathing air compressor in a 27 °C (81 °F) environment, would have an inter-stage temperature inside the cylinder of about 107 °C (225 °F). The calculation does not account for anything outside of nominal conditions, but it indicates the instantaneous temperature at the moment of peak pressure. In reality the compressed air is cooled between stages, and the compressor itself is fairly hot, so direct measurement would be relatively simple, but this does not take into account time of exposure to temperature. ^[7]

The actual gas temperature at the outlet from each stage was reported to be around 66 °C (151 °F) This is considered to be hot enough to kill SARS-CoV-2, so it is considered unlikely that the virus would survive passing through a compressor. Infected droplets exhaled by a person can be as small as 0.5 micron, so the compressor particle filter systems would not reliably remove them. ^[7]

There are many disinfectants that are assumed to be effective on SARS-CoV-2 based on their effectiveness on similar viruses which are considered more resistant to deactivation. ^[6] The United States Environmental Protection Agency (EPA) publish a list of disinfectant products which meet the EPA's criteria for use against SARS-CoV-2 in "List N: Disinfectants for Use Against SARS-CoV-2" in the absence of specific testing on SARS-CoV-2. ^[8]

Divers Alert Network have recommended following Centers for Disease Control (CDC) advice on using a solution of household bleach diluted 4:100 in water with a contact time of 1 minute followed by a thorough rinse in water to remove residual disinfectant. ^[1] As of April 24 2020, Steramine, a quaternary ammonium compound popular for disinfecting diving equipment, did not appear on the EPA's "List N" and is therefore not endorsed for disinfecting SARS-CoV-2. However, many other products using quaternary ammonium compounds are on List N. ^[8] Quaternary ammonium-containing products are harmful to the environment and suitable precautions should be applied to their use and disposal. ^[7]

Sodium hypochlorite bleach is a strong oxidant which has been tested in different concentrations, and is proven to be effective against viruses by damaging the viral genome. The World Health Organization (WHO) recommend a 1:100 dilution of 5% sodium hypochlorite bleach solution for general disinfection, which yields 0.05% or 50 ppm of the active ingredient which requires a soaking time of 30 minutes or at least 10 minutes wet time if sprayed onto a nonporous surface. Specific studies on SARS-CoV-2 found that a sodium hypochlorite bleach concentration of 0.1% (1,000 ppm) was necessary to adequately reduce infectivity when sprayed onto a non-porous surface, and that it would inactivate the virus within 1 minute. A study on SARS-CoV-1 showed that a 1:100 dilution (0.05%) inactivated the virus after an immersion of 5 minutes. ^[7] Bleach-based disinfectants may cause accelerated degradation of some materials used in breathing apparatus components. ^[9]

Specific equipment

Apeks, a manufacturer of scuba regulators and other diving equipment, specifically warn against the use of bleach based disinfectants or disinfectants known to be corrosive, on scuba regulators, as they can cause accelerated degradation of the equipment. They recommend different procedures based on risk. ^[9]

• Low risk, where the equipment is used by one person and there is no reason to assume environmental contamination: The regulator may be washed after use in warm fresh water with household dish-washing detergent, rinsed with fresh water, purged, drained, and dried before storage. ^[9]
• Moderate risk, where the equipment is used by more than one person: The regulator may be washed to remove deposits of organic matter, rinsed in fresh water, and drained, then immersed in a suitable strength solution of bleach-free disinfectant certified as effective against the expected pathogens, for a suitable period – 20 minutes is suggested – followed by a final fresh water rinse, purge, drain and drying before storage or re-use. ^[9]
• Higher risk, where the equipment is used by more than one person: A higher concentration of disinfectant can be used, following the same procedures. ^[9]

Targeted chemical decontamination

This section needs expansion. You can help by adding to it. (October 2021)

See also

• Decontamination  – Process of removing or neutralising harmful substances
• Disinfectant  – Antimicrobial agent that inactivates or destroys microbes
• Epidemiology  – Study of health and disease within a population
• Infection  – Invasion of an organism's body by pathogenic agents
• Occupational health  – Field concerning the health of people at work
• Occupational hygiene  – Management of workplace health hazards
• Sterilization (microbiology)  – Process that eliminates all biological agents on an object or in a volume

Related Research Articles

Hygiene is a set of practices performed to preserve health. According to the World Health Organization (WHO), "Hygiene refers to conditions and practices that help to maintain health and prevent the spread of diseases." Personal hygiene refers to maintaining the body's cleanliness. Hygiene activities can be grouped into the following: home and everyday hygiene, personal hygiene, medical hygiene, sleep hygiene, and food hygiene. Home and every day hygiene includes hand washing, respiratory hygiene, food hygiene at home, hygiene in the kitchen, hygiene in the bathroom, laundry hygiene,and medical hygiene at home.And also environmental hygiene in the society to prevent all kinds of bacterias from penetrating into our into our homes.

Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids, and gases from water. The goal is to produce water that is fit for specific purposes. Most water is purified and disinfected for human consumption, but water purification may also be carried out for a variety of other purposes, including medical, pharmacological, chemical, and industrial applications. The history of water purification includes a wide variety of methods. The methods used include physical processes such as filtration, sedimentation, and distillation; biological processes such as slow sand filters or biologically active carbon; chemical processes such as flocculation and chlorination; and the use of electromagnetic radiation such as ultraviolet light.

A blood-borne disease is a disease that can be spread through contamination by blood and other body fluids. Blood can contain pathogens of various types, chief among which are microorganisms, like bacteria and parasites, and non-living infectious agents such as viruses. Three blood-borne pathogens in particular, all viruses, are cited as of primary concern to health workers by the CDC-NIOSH: HIV, hepatitis B (HVB), & hepatitis C (HVC).

A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical or chemical process that kills all types of life. Disinfectants are generally distinguished from other antimicrobial agents such as antibiotics, which destroy microorganisms within the body, and antiseptics, which destroy microorganisms on living tissue. Disinfectants are also different from biocides—the latter are intended to destroy all forms of life, not just microorganisms. Disinfectants work by destroying the cell wall of microbes or interfering with their metabolism. It is also a form of decontamination, and can be defined as the process whereby physical or chemical methods are used to reduce the amount of pathogenic microorganisms on a surface.

Wilderness-acquired diarrhea is a variety of traveler's diarrhea in which backpackers and other outdoor enthusiasts are affected. Potential sources are contaminated food or water, or "hand-to-mouth", directly from another person who is infected. Cases generally resolve spontaneously, with or without treatment, and the cause is typically unknown. The National Outdoor Leadership School has recorded about one incident per 5,000 person-field days by following strict protocols on hygiene and water treatment. More limited, separate studies have presented highly varied estimated rates of affliction that range from 3 percent to 74 percent of wilderness visitors. One survey found that long-distance Appalachian Trail hikers reported diarrhea as their most common illness. Based on reviews of epidemiologic data and literature, some researchers believe that the risks have been over-stated and are poorly understood by the public.

Diving disorders, or diving related medical conditions, are conditions associated with underwater diving, and include both conditions unique to underwater diving, and those that also occur during other activities. This second group further divides conditions caused by exposure to ambient pressures significantly different from surface atmospheric pressure, and a range of conditions caused by general environment and equipment associated with diving activities.

Infection prevention and control is the discipline concerned with preventing healthcare-associated infections; a practical rather than academic sub-discipline of epidemiology. In Northern Europe, infection prevention and control is expanded from healthcare into a component in public health, known as "infection protection". It is an essential part of the infrastructure of health care. Infection control and hospital epidemiology are akin to public health practice, practiced within the confines of a particular health-care delivery system rather than directed at society as a whole.

Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons, solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapour from the contaminants, or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting clean ups are time-consuming and expensive tasks, and require expertise in geology, hydrology, chemistry, computer modelling, and GIS in Environmental Contamination, as well as an appreciation of the history of industrial chemistry.

Portable water purification devices are self-contained, easily transported units used to purify water from untreated sources for drinking purposes. Their main function is to eliminate pathogens, and often also of suspended solids and some unpalatable or toxic compounds.

Swimming pool sanitation is the process of ensuring healthy conditions in swimming pools. Proper sanitation is needed to maintain the visual clarity of water and to prevent the transmission of infectious waterborne diseases.

Potable water diving is diving inside a tank that is used for potable water. This is usually done for inspection and cleaning tasks. A person who is trained to do this work may be described as a potable water diver. The risks to the diver associated with potable water diving are related to the access, confined spaces and outlets for the water. The risk of contamination of the water is managed by isolating the diver in a clean dry-suit and helmet or full-face mask which are decontaminated before the dive.

A virucide is any physical or chemical agent that deactivates or destroys viruses. The substances are not only virucidal but can be also bactericidal, fungicidal, sporicidal or tuberculocidal.

In health care facilities, isolation represents one of several measures that can be taken to implement in infection control: the prevention of communicable diseases from being transmitted from a patient to other patients, health care workers, and visitors, or from outsiders to a particular patient. Various forms of isolation exist, in some of which contact procedures are modified, and others in which the patient is kept away from all other people. In a system devised, and periodically revised, by the U.S. Centers for Disease Control and Prevention (CDC), various levels of patient isolation comprise application of one or more formally described "precaution".

A fomite or fomes is any inanimate object that, when contaminated with or exposed to infectious agents, can transfer disease to a new host.

Viruses are a major cause of human waterborne and water-related diseases. Waterborne diseases are caused by water that is contaminated by human and animal urine and feces that contain pathogenic microorganisms. A subject can get infected through contact with or consumption of the contaminated water. Viruses affect all living organisms from single cellular plants, bacteria and animal to the highest forms of plants and animals including human beings. Within a specific kingdom the localization of viruses colonizing the host can vary: Some human viruses, for example, HIV, colonizes only the immune system, while influenza viruses on the other hand can colonize either the upper respiratory tract or the lower respiratory tract depending on the type. Different viruses can have different routes of transmission; for example, HIV is directly transferred by contaminated body fluids from an infected host into the tissue or bloodstream of a new host while influenza is airborne and transmitted through inhalation of contaminated air containing viral particles by a new host. Research has also suggested that solid surface plays a role in the transmission of water viruses. In a experiments that used E.coli phages, Qβ, fr, T4, and MS2 confirmed that viruses survive on a solid surface longer compared to when they are in water. Because of this adaptation to survive longer on solid surfaces, viruses now have a prolonged opportunities to infect humans. Enteric viruses primarily infect the intestinal tract through ingestion of food and water contaminated with viruses of fecal origin. Some viruses can be transmitted through all three routes of transmission.

Prevention of viral hemorrhagic fever is similar for the different viruses. There are a number of different viral hemorrhagic fevers including Ebola virus disease, Lassa fever, Rift valley fever, Marburg virus disease, Crimean-Congo haemorrhagic fever (CCHF) and yellow fever. Lassa, Ebola, Marburg and CCHF can be spread by direct contact with the body fluids of those infected. Thus the content here covers the prevention of Ebola.

A toilet plume is the dispersal of microscopic sewage particles & water vapor as a result of flushing a toilet. Normal use of a toilet by healthy individuals is considered to be a lower health risk. However this rapidly changes if an individual is fighting an illness and currently shedding out a virulent pathogen in their urine, feces or vomitus. There is evidence that specific pathogens such as norovirus or SARS coronavirus could potentially be spread by toilet aerosols, but as of 2015, no direct experimental studies had clearly demonstrated or refuted actual disease transmission from toilet aerosols. It has been hypothesized that dispersal of pathogens may be reduced by closing the toilet lid before flushing, and by using toilets with lower flush energy.

Chlorine-releasing compounds, also known as chlorine base compounds, is jargon to describe certain chlorine-containing substances that are used as disinfectants and bleaches. They include the following chemicals: sodium hypochlorite, chloramine, halazone, and sodium dichloroisocyanurate. They are widely used to disinfect water and medical equipment, and surface areas as well as bleaching materials such as cloth. The presence of organic matter can make them less effective as disinfectants. They come as a liquid solution, or as a powder that is mixed with water before use.

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 so that the risk can be reduced to an acceptable level. These are based on preventing contact of the hazardous materials with the divers and other personnel, generally by encapsulating the affected personnel in personal protective equipment (PPE) appropriate to the hazard, and by effective decontamination after contact between the PPE and the hazardous materials.

Hazard controls for COVID-19 in workplaces are the application of occupational safety and health methodologies for hazard controls to the prevention of COVID-19. Multiple layers of controls are recommended, including measures such as remote work and flextime, personal protective equipment (PPE) and face coverings, social distancing, and enhanced cleaning programs. Recently, engineering controls have been emphasized, particularly stressing the importance of HVAC systems meeting a minimum of 5 air changes per hour with ventilation or MERV-13 filters, as well as the installation of UVGI systems in public areas.

References