Efficacy of water skin decontamination in vivo in humans: A systematic review

Skin decontamination with and without water irrigation

OBJECTIVE

Rinsing only with water or washing with soap and water are common methods of skin decontamination for skin contaminated during a chemical hazard release. The null hypothesis was that a 15-minute water irrigation (decontamination method 1) would not be superior to decontamination using a microfiber towel, followed by a wet wipe (Signature Select Softly Flushable Tissue Better Living Brands LLC, Pleasanton, CA), followed by using another microfiber towel (decontamination method 2).

METHODS

A simulated contaminant (Magic Fluorescent Glow Paint for Face and Body, iLC Shenzhen Fulimei Technology Co. LTD, Shenzhen, the People's Republic of China) was applied to the dorsal skin of each subject's forearms. Then, photographs of these subject's skin were taken before and after decontamination of the simulated contaminant by using either decontamination method 1 or 2. Each of the subjects underwent both decontamination methods in separate trials, with each subject using one forearm for decontamination method 1 and their other forearm for decontamination method 2. Discrete points of contamination were quantified on the photographs that were taken with the skin illuminated by ambient visible light or ultraviolet light (395nm, Roceei ultraviolet flashlight, China).

RESULTS

Under visible light, no residual contamination was seen by inspecting photographs taken after decontaminating with either method. Under ultraviolet light, less visible contamination was seen by inspecting photographs taken after decontaminating with method 1 than after decontaminating with method 2.

CONCLUSION

In this study, skin decontamination with water irrigation was superior to skin decontamination without water irrigation.

Percutaneous Absorption of Fireground Contaminants: Naphthalene, Phenanthrene, and Benzo[a]pyrene in Porcine Skin in an Artificial Sweat Vehicle

Firefighters face significant risks of exposure to toxic chemicals, such as polycyclic aromatic hydrocarbons (PAHs), during fire suppression activities. PAHs have been found in the air, on the gear and equipment, and in biological samples such as the skin, breath, urine, and blood of firefighters after fire response. However, the extent to which exposure occurs via inhalation, dermal absorption, or ingestion is unclear. In this study, three PAHs, naphthalene, phenanthrene, and benzo[a]pyrene, were applied to porcine skin in vitro in an artificial sweat solution to better gauge firefighters' dermal exposures while mimicking their sweaty skin conditions using an artificial sweat dosing vehicle. Multiple absorption characteristics were calculated, including cumulative absorption, percent dose absorbed, diffusivity, flux, lag time, and permeability. The absorption of the PAHs was greatly influenced by their molecular weight and solubility in the artificial sweat solution. Naphthalene had the greatest dose absorption efficiency (35.0 ± 4.6% dose), followed by phenanthrene (6.8 ± 3.2% dose), and lastly, benzo[a]pyrene, which had the lowest absorption (0.03 ± 0.04% dose). The lag times followed a similar trend. All chemicals had a lag time of approximately 60 min or longer, suggesting that chemical concentrations on the skin may be reduced by immediate skin cleansing practices after fire exposure.

Exposure to organophosphorus compounds: best practice in managing timely, effective emergency responses

Increasing indications, reports and studies demonstrate that threats from the deliberate use of chemical weapons remain high and are evolving. One of the deadliest classes of chemical weapons are the organophosphorus nerve agents. It is now clear that both state and non-state actors have the ability to deploy and use these types of weapons against individuals and the wider civilian population posing a real and significant threat. The objective of this article is to provide an overview of the issues impacting on a timely critical response to the accidental or deliberate release of Organophosphorus Nerve Agents in order to enhance the understanding of their effects and provide guidance on how first responders might better treat themselves or victims of exposure through a discussion of available evidence and best practices for rapid skin decontamination. The article also examines use of the current nomenclature of 'wet' and 'dry' to describe different forms of decontamination. One of the key conclusions of this article is that adequate preparedness is essential to ensuring that responders are trained to understand the threat posed by Organophosphorus Nerve Agents as well as how to approach a contaminated environment. A key aspect to achieving this will be to ensure that generic medical countermeasures are forward-deployed and available, preferably within minutes of a contamination and that first responders know how to use them.

Efficacy of soap and water-based skin decontamination using in vitro animal models: A systematic review

Water and/or soap and water solutions have historically been used as first-line decontamination strategies for a wide variety of dermal contaminants from workplace exposure, environmental pesticides, and civilian chemical warfare. Although water and/or soap and water solutions are often considered a gold standard of decontamination, many studies have found other decontamination methods to be superior. This systematic review summarizes the available data on in vitro animal models contaminated with a various chemicals and their decontamination with water and/or soap and water solutions using in vitro animal models. A comprehensive literature search was performed using Concordance, Embase, PubMed, Medline, Web of Science, and Google Scholar to find in vitro animal studies that provided data on dermal decontamination using water and/or soap and water solutions. Five studies were included that analyzed 11 contaminants across two in vitro animal models (rats and pigs). Water alone was used as a decontamination method for 63.6% of the contaminants (n = 7/11) and water and soap solutions for decontamination in 54.6% of contaminants (n = 6/11). Water alone provided incomplete contaminant removal of five of seven contaminants studied; soap and water did not show significant difference in decontamination when compared with other solutions for all four contaminants and was superior to water for both contaminants studied. Water and/or soap and water are used as decontamination strategies for a variety of dermal contamination events, but for many contaminants, they do not provide complete contamination when compared with newer decontamination solutions studied with in vitro animal models.

Do cold weather temperatures affect the efficacy of skin decontamination?

Skin decontamination in cold weather temperatures might be challenging due to the aggravating circumstances. However, no information is available on the efficacy of commonly used procedures in winter conditions. Therefore, the efficacy of the reactive skin decontamination lotion (RSDL) and soapy water decontamination following skin exposure to the nerve agent VX was evaluated at three ambient air temperatures (-5°C, -15°C and room temperature). Experiments were performed in vitro using human dermatomed skin. The ability of RSDL to degrade VX at the three different air temperatures was separately evaluated. The ambient air temperature in experiments without decontamination did not influence the penetration rate of VX through skin. RSDL decontamination was highly efficient in removing VX from skin when performed in all three ambient temperatures, despite the slower agent degradation rate of VX at the lower temperatures. Decontamination with soapy water at RT resulted in an increased skin penetration of VX compared with the control without decontamination; however, in colder temperatures the VX skin penetration was similar to the corresponding control without decontamination. At RT, dry removal prior to washing with soapy water did not improve decontamination of VX compared with washing solely with soapy water. This study demonstrated high efficacy of RSDL decontamination following skin exposure to VX also at cold temperatures. The previously reported 'wash-in' effect of soapy water on VX skin penetration was reduced at cold temperatures. Altogether, this study found a scientific basis to establish guidelines for skin decontamination of chemical casualties at cold weather temperatures.

Efficacy of water-only or soap and water skin decontamination of chemical warfare agents or simulants using in vitro human models: A systematic review

Water-only or water and soap are widely recommended as preferred solutions for dermal decontamination. However, limited efficacy data exist. We summarized experimental studies evaluating in vitro efficacy of water-only or soap and water in decontaminating chemical warfare agents (CWA) or their simulants from human skin models. Embase, Covidence®, MEDLINE, PubMed, Web of Science, and Google Scholar were searched for articles using water-only or soap and water decontamination methods for removal of CWA/CWA simulants in in vitro human skin models. Data extraction was completed from seven studies, yielding seven contaminants. Water-only decontamination led to partial decontamination in all skin samples (100%, n = 81/81). Soap and water decontamination led to partial decontamination in all skin samples (100%, n = 143/143). Four studies found decontamination to either paradoxically enhance absorption of contaminants or their penetration rates, known as the "wash-in" effect. Despite recommendations, water-only or water and soap decontamination were found to yield partial decontamination of CWA or their simulants in all human in vitro studies. Thus, more effective decontaminating agents are needed. Some studies demonstrated increased or faster penetration of chemicals following decontamination, which could prove deadly for agents such as VX, although these findings require in vivo validation. Heterogeneity in experimental setups limits interstudy comparison, and it remains unclear when water-only or water and soap are ideal decontaminants, which requires more studies. Pending manuscripts will summarize in vivo human and animal efficacy data. International harmonized efficacy protocol should enable more efficient public health decisions for evidence-based public health decisions.

Efficacy of soap and water based skin decontamination using in vivo animal models: a systematic review

Water-only or soap and water solutions are considered a gold standard for skin decontamination. However, there is lack of conclusive data regarding their efficacy. The aim of this study was to summarize in vivo animal model data on skin decontamination using water-only, and/or soap and water. Covidence, Embase, MEDLINE, PubMed, Web of Science, and Google Scholar were searched to identify relevant articles using water-only or soap and water decontamination methods in in vivo animals. Data extraction was completed from studies, representing three animal models, and 11 contaminants. Results demonstrated water-only decontamination solutions led to complete decontamination in 3.1% (n = 16/524) protocols, incomplete decontamination in 90.6% (n = 475/524) of protocols, and mortality in 6.3% (n = 33/524) of protocols. Soap and water decontamination solutions resulted in complete decontamination in 6.9% (n = 8/116) protocols, incomplete decontamination in 92.2% (n = 107/116) of protocols, and mortality in 6.9% (n = 8/116) of protocols. Although water only, or soap and water is considered a gold standard for skin decontamination, most papers investigated found that water only, and soap and water provided incomplete decontamination. Due to the insufficient data, and limitations that hinder the applicability of available data, evidence indicates that more contemporary studies investigating skin decontamination are needed, and compared to other model species, including humans, when practical.