22
Oct
Continued Skin Contact with Disinfectant Use to Prevent COVID-19 Infection Can Cause Harmful Skin Reactions
(Beyond Pesticides, October 22, 2020) Prolonged dermal (skin) exposure to hazardous disinfectants, via handling and/or residue on surfaces, can induce the risk of adverse skin reactions (i.e., inflammation, burns, necrosis), according to a novel review analysis published in Clinics in Dermatology. Researchers of the review, “Dermatologic reactions to disinfectant use during the COVID-19 pandemic,” examine skin reactions associated with dermal exposure to various disinfectants approved for use against COVID-19 by the European Chemical Agency (ECA) and the U.S. Environmental Protection Agency (EPA). The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) classifies disinfectants as pesticides, so it is up to the states to delegate training, registration, and enforcement. Many states enforce pesticide training that allows professional applicators to learn how to handle, apply, and store pesticides properly. However, many of these same states do not have professional training for disinfectant use, especially wide-scale applications. Consequently, disinfectant applications are now more pervasive than ever, especially as school reopenings ensues. Considering failure to “Comply with Labeling and Permit Conditions” was the most common pesticide use violation of 2018, according to the California Department of Pesticide Regulations (DPR), advocates are urging global leaders to recognize the potential impacts that frivolous disinfectant use can have on the largest human organ, the skin.
Amidst the outbreak of SARS-CoV-2 (COVID-19), the global demand for disinfectants and sanitizers has increased substantially as a means of preventing illness in residential and non-residential settings. Initially, public health officials considered disinfecting highly trafficked areas as the most effective way to combat COVID-19. This notion has led to improper disinfectant practices in many countries where trucks, drones, or robots disperse massive amounts of disinfectants into public areas. Furthermore, the Centers for Disease Control (CDC) has reported a sharp increase in calls to poison control centers regarding illnesses resulting from the use or misuse of toxic disinfectants during the pandemic. The World Health Organization (WHO) and other infectious disease specialists condemn indiscriminate and vast amounts of disinfectant spraying in public areas as it is both ineffective and a health hazard on contact or when combined with other disinfectants.
As the pressure to reopen public facilities, like schools, restaurants, gyms, etc., increases, the lack of proper disinfection guidelines and monitoring generates concerns, especially as a means to prevent the spread of COVID-19 includes spraying students with disinfectants. The active ingredients in most disinfectants are harmful because these chemical compounds have corrosive and irritating properties that should never encounter bare skin.
Researchers examined studies related to skin reactions caused by various chemical classes of disinfectants common in consumer products. Furthermore, researchers assessed adverse skin reactions to disinfectant use and the chemicals’ skin penetration ability via transdermal penetration and interactions with skin components that facilitate skin penetration.
There are ten different chemical classes included in the review: alcohols (i.e., isopropanol, ethanol), biguanides (i.e., polyhexanide), α-hydroxy acids (AHA) (i.e., citric acid, lactic acid, glycolic acid), chlorine and chlorine compounds (i.e., sodium hypochlorite/bleach, sodium chloride), metal ions (i.e., silver, nanosilver), aldehydes (i.e., glutaraldehyde), peroxygen compounds (i.e., hydrogen peroxide, peroxyacetic acid), iodophors (i.e., containing iodine and a surfactant/wetting-agent), phenolic compounds (i.e., cresols, hexachlorobenzene, chlorophenols), anionic surfactants (i.e., dodecylbenzene sulfonic acid), and cationic surfactants (i.e., quaternary ammonium compounds).
According to the review, most disinfectants cause some form of acute skin irritation. Although certain disinfectants are less harmful upon dermal contact than others, many of these chemicals cause irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD). ICD is a non-immune response that manifests into a localized skin inflammation by directly damaging the skin following toxic agent exposure. ACD is an immune response to skin contact with a dermal allergen that an individual is already allergic (sensitized) to, causing non-localized skin inflammation and/or systemic bodily response. However, chronic, cumulative exposure to more mild chemical irritants can still elicit a skin reaction.
Alcohols have low transdermal penetration properties, even upon excessive use. Therefore, WHO recommends the use of either ethanol (80%v/v) or isopropanol (70%v/v) upon direct contact with skin via hand rubs. However, some research suggests alcohol-based products can cause ICD and ACD. Studies find an association with pre-irritated skin (e.g., by detergents or water, a cut) and a burning sensation upon contact with alcohol-based antiseptic products. Although allergic reactions, like ACD, to dermal contact with alcohol antiseptic products lack considerable scientific evidence, some studies report allergic reactions such as contact urticarial (hives). Furthermore, solvents in alcohol products may cause mild irritation to the skin due to impurities, aldehyde metabolites, or fragrances.
Although aldehydes, like glutaraldehyde, do not readily penetrate the skin, dermal contact with high concentrations of glutaraldehyde (~20%) can cause ICD and necrosis (death of cells in an organ/tissue). Occupational and experimental exposure to aldehydes frequently causes ACD. Furthermore, upon contact with skin, glutaraldehyde produces a “tanning effect,” triggering yellow-brown skin discoloration due to an alternation of protein structure from chemical crosslinking of proteins like keratin and collagen.
Skin penetration of biguanides like polyhexanide low and ACD is rare. However, research finds increasing reports of ACD incidents over the years, potentially due to the cross-reaction this chemical has with other biguanides like chlorhexidine. Moreover, polyhexanide concentrations above 1.2% are moderate to strong skin sensitizers (allergens), and although rare, can cause anaphylaxis upon exposure to wounded skin.
Chlorine and chlorine compounds concentrations between 5-10% can cause skin reactions that manifest as a burning sensation, pain, redness, edema, blisters, and necrosis. Any concentration of hypochlorite—a chlorine and chlorine compound—above 10% is corrosive and can cause chemical burns. Upon dilution to 0.1%, these chemical compounds have low skin penetrative abilities due to its high reactivity, oxidizing, and alkalinity properties when in contact with proteins on the skin. However, these same properties are what worsens the adverse effect of these chemicals when mixed with other disinfectant products, including sodium hydroxide (exothermic reaction), acetic acid (toxic gas), alcohol (toxic gas), and household cleaners that contain ammonia (toxic gas). Although there is little dermal uptake of poisonous gas by unwounded skin, the gas can still irritate the skin. Furthermore, the oxidizing properties of chlorine dioxide—a highly reactive and unstable chlorine compound—have similar effects in the skin as hypochlorite compounds, but milder due to chlorine dioxide’s rapid degradation.
Iodophors, consisting of iodine complexed with a nonionic surfactant, cause less skin irritation than iodine disinfectants. However, the severity of transdermal penetration is time-dependent, as extensive dermal contact with chemical concentrations at 10% triggers ICD along with chemical burns, pain, blistering lesions, and tissue necrosis. Although pre-wounded skin is more prone to the side effects of iodophor, the continuous release of free iodine acting as a weak oxidant can also trigger side effects. Reports of ACD and allergic reactions to iodophors are rare, and other ingredients in iodophor products may be the culprit.
Although metal ions, like silver and nanosilver, are not readily absorbed via the skin, and ACD is mainly due to other constituent ingredients, topical application of metal ions to a wound may induce ICD, causing localized brown-black skin discoloration.
According to the review, alpha-hydroxy acids (AHA) have skin penetrative properties that are time-, pH-, and concentration-dependent. At lower concentrations, AHAs have little to no skin reaction and are commonplace in dermatologic practice. Usually, concertation of 10% or less and a pH of 3.5 or higher can cause burning, dermatitis, skin peeling, itching, and moderate sunburns. Skin reactions, including epidermal and dermal thickness, occur at a concentration of 20-40% for citric acid (CA) and glycolic acid (GA) and 12% for lactic acid (LA). AHA may decrease pigment deposition in the skin and induce ACD that trigger hives and skin photosensitivity, with concentrations of GA and CA at 3% or more enhancing ultraviolet (UV) damage to the skin.
The rapid chemical degradation of peroxygen compounds like hydrogen peroxide impedes an assessment of the dermal absorption rate. Although non-threatening, temporary skin bleaching can occur at some concentrations, while only concentrations of hydrogen peroxide at 35% or higher manifest skin reactions like reversible erythema and edema, irreversible skin peeling, and rare vacuolar eruption. Concentrations of hydrogen peroxide at 50% can induce chemical burns that can occur at lower concentrations if the skin experiences prolonged exposure to the chemical. Despite hydrogen peroxides being a strong oxidizing antiseptic, it is generally non-irritating at a concentration of 10% or less. On the other hand, the strong oxidative properties of peroxygen compounds like peracetic acid (PA) cause skin reactions upon repeated exposure, including acute skin irritation, erythema, scaling, and roughness at concentrations as low as 0.1%. The review notes that the regular use of PA at a concentration of 0.2-0.5% during the 2002-2003 SARS outbreak triggered skin irritation, burning, and itching lasting up to 5 hours.
Phenolic compounds, like phenol and its chemical derivatives (ortho phenyl phenol [OPP] and ortho-benzylpara-chlorophenol [OBPCP]), have high skin penetrative properties and can trigger ACD skin reaction soon after contact at a concentration as low as 0.1%. Skin exposure to concentrations of OPP and OBPCP at 1% can reduce pigmentation and induce vitiligo. Persistent exposure to 0.5% halogenated (containing one or more added halogen atom) phenol triggers chemical burns and fingertip decomposition.
Lastly, the review discusses the skin reactions associated with anionic and cationic surfactants. Anionic surfactants, like sodium dodecyl benzenesulfonate, have low transdermal penetration, mainly penetrating the skin via prolonged, repeated exposure, resulting in moderate to severe erythema (rash) and rough skin. Cationic surfactants or quaternary ammonium compounds (“quats”), like benzalkonium chloride (BAC), can readily penetrate the skin, inducing skin irritation and inflammation at concentrations as low as 0.1%. Although rare, the review reports incidents of ACD at remarkably low concentrations (0.01%) and instant hypersensitivity, with hives, swelling, rash, and itchiness at higher concentrations (1 – 10%). New quat formulas, like didecyl dimethyl ammonium chloride (DDAC), harm the skin (in vitro) and may trigger varied hypersensitivity that induces antibody and lymphocyte cell response. Furthermore, DDAC has skin irritant and sensitizer properties potentially stronger than old formula quats like BAC.
The skin responds to numerous external stimuli that can change its morphological (shape/structure), physiological (function), and histological (tissue) properties. Some responses to external stimuli are typical, including skin exposure to sunlight (UV-light) for tanning or water for wrinkling. However, exposure to excessive stimuli, including environmental contaminants, can propagate adverse, permanent changes to the skin. Just as excessive exposure to UV rays can cause skin discoloration and cancer, prolonged dermal contact with disinfectants can cause a plethora of adverse reactions, including skin discoloration and cancer. Considering one of the most prominent routes of pesticide exposure is dermal—compromising 95 percent of all pesticide exposure incidents—and that most disinfectants are potential skin irritants and/or sensitizers (allergens), it is essential to mitigate direct skin contact with these toxic chemicals and enforce proper application protocol.
While EPA has certified a large number of disinfectants as effective against SARS-CoV-2 (List N), many of these chemicals are hazardous and weaken the respiratory, immune, and nervous systems. The most concerning disinfectants in the dermatologist review include quaternary ammonium compounds (“quats”), phenolic compounds, metal ions, chlorine and chlorine compounds, aldehydes, peroxyacetic acid (peroxygen compounds), glycolic acid (AHA), biguanide, and iodophors. All of the said chemicals reside on Beyond Pesticides’ “bad” list of “Disinfectants to Avoid.” Many of these chemical causes a long list of adverse effects—from asthma and other respiratory, problems, to endocrine disruption, infertility, and cancer.
More than a third of U.S. residents participate in high-risk COVID-19 practices, misusing toxic disinfectant cleaners and disinfectants to prevent infection. “Quats” are among some of the most harmful disinfectants, as their “long-lasting” properties have adverse impacts on human health, which has extensive documentation in literature. Some adverse effects comprise mutations, lower fertility, and increase antibiotic resistance. Overuse of quat disinfectants (containing BAC) in ICE detainment centers caused nose bleeds and other adverse health effects. Furthermore, Beyond Pesticides receives questions from concerned teachers asking for less harmful disinfectants to use in the classroom, especially as many are experiencing the adverse impacts of improper disinfectant use (i.e., chemical skin burns, respiratory issues). Since “quats” are in most disinfectant products, it remains ubiquitous in the environment as misuse continues.
Disinfectant products containing phenolic compounds are also concerning due to its wide range of adverse effects. Its derivative (OPP) is possibly carcinogenic, and exposure to phenolic compounds via skin or inhalation can trigger headaches, burning eyes, muscle tremors, skin burns, irregular heartbeat, severe injury to heart, liver, kidneys, and lungs, cancer, and even death. Although some individuals practicing high-risk COVD-19 prevention practices use quats and phenolic compounds, sodium hypochlorite (chlorine bleach) remains the most widely misused disinfectant. CDC’s report on an increase in poison control calls due to disinfectant misuse notes that a majority pertained to bleach products, a 62% increase from 2019, with a total disinfectant-related call increase by 108.8% between 2019 and 2020. Thirty-nine percent of Americans participate in high-risk COVID-19 prevention practices, washing food with bleach, and using disinfectants on bare skin, with four percent drinking or gargling with diluted bleach solutions or other disinfectants. Bleach misuse can cause respiratory problems (i.e., asthma, wheezing, coughing), skin burns, nervous system, extreme headaches, migraines, and vomiting.
Many of these toxic disinfectants are harmful via more than one exposure route as ingestion and inhalation also trigger potentially more harmful effects. Although chemical disinfectants kill viruses, bacteria, and other microbes via cell wall and protein destruction, they can also irritate and destroy the mucous membranes in animal and human respiratory and digestive tracts upon ingestion or inhalation. Occasionally, this exposure can lead to death in extreme cases. People who have a preexisting condition or are of advanced age, who may have a weakened immune or respiratory system are more vulnerable to the effects of the virus. Many of the products approved as disinfectants have negative impacts on the respiratory or immune system, thus reducing resistance to the disease. When managing viral and bacterial infections, chemicals that exacerbate the risk to vulnerable individuals are of serious concern.
The review concludes that even exposure to disinfectant compounds with non-irritant properties can allow an individual to develop sensitization overtime. Not only can frequent exposure to disinfectants trigger sensitization, but also exposure disproportionately impacts essential workers who apply disinfectants to these frequented areas. Furthermore, the combined use of various toxic disinfectants can act synergistically, enhancing adverse effects on the body. Conveniently, there are many safer disinfectants on EPA’s list N that are effective against the virus, including citric acid, ethanol, isopropanol, L-lactic acid, hydrogen peroxide, sodium bisulfate, dodecylbenzene sulfonic acid, and thymol. These chemicals are present on Beyond Pesticides’ “good” list of “Disinfectants to look For” as natural-based substances tend to be safer while still effective at eliminating the virus on surfaces. However, many disinfectant products containing these active ingredients also contain other (inert) ingredients that typically make up most of the product formula. Inert ingredients can be toxic, and EPA does not require manufacturers to disclose ingredients on the product label, so manufacturers choose to participate with individual product reviews. Although EPA’s Design for the Environment Program (DfE), or Safer Choice Program, subdivides products with these active ingredients by evaluating the hazards associated with undisclosed inert ingredients, individuals should use precautions and adhere to label direction to mitigate any unintentional adverse impacts effects.
The authors of the review provide various safety concerns to consider when using chemical disinfectants:
• Damaged skin is prone to adverse reactions from a direct absorption of disinfectants, and extra care should be given to avoid contact with disinfectants.
• While multiple disinfectants may be used together or formulated as a single product to achieve synergistic effects, an enhanced adverse effect is expected.
• Whenever dermatitis is known, disinfectants that are weak or non-irritants and sensitizers should be prioritized. Patch testing may be considered. It is important to avoid using disinfectants from a similar class that is known to be allergic to the users in consideration of a potential cross-reactivity.
• It is necessary to use protective garments during handling to avoid direct contact from spillage. Even with regular use of protective attires, unnoticeable punctures in the gloves on multiple use and the handling of disinfected surfaces can expose users to contamination. Possible interactions of disinfectants with protective garments may occur.
• For example, glutaraldehyde at 2 – 3.4% may penetrate latex gloves after 45 min and thus, butyl rubber and nitrile rubber gloves are recommended.
• Emphasis is given only on the dermatological reactions in this review but the exposure through other manners such as ocular route and inhalation is often significant and most probably toxic.
• Chlorine compounds are known to emit chlorine gas during preparation and application. The exposure to the eyes is thus high and toxic.
As various public facilities in the U.S. begin to reopen at higher capacities, and people continue to protect themselves long-term from coronavirus, global leaders and individuals alike must decrease the reliance on toxic chemical disinfectants to safeguard against disease. Public health officials should carefully examine disinfectant practices and products to ensure chemical use does not introduce an unnecessary health threat while elevating the hazards associated with infectious disease crises. In addition to social distancing guidelines and mask requirements, the use of safer disinfection products can reduce human’s and wildlife’s vulnerability to this deadly illness.
Because widely available disinfectants are very hazardous, it is important to learn how to adopt protections from COVID-19 while not exposing yourself, family, school, or workplace to hazardous disinfectants that exacerbate the risks associated with the virus. For more information on safe disinfectants, visit Beyond Pesticides’ webpage on Disinfectants and Sanitizers, including a factsheet on meeting health protection needs for school reopening as schools must have adequate resources to ensure safety.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Clinics in Dermatology
