Household cleaners of various descriptions are present in every home and companion animals are at risk of exposure during or after use and from leaking containers or spills. In many cases, exposed animals may appear well for some hours after exposure. Therefore, presentation at a veterinary practice may be delayed and the exposure to the cleaner not associated with clinical signs. It is important to determine the type of product involved (Figure 1) (Table 1) in order for the potential risk to be assessed (Table 2) and appropriate treatment provided. If possible, it is always useful if the owner can bring in any suspect product so that the full name and contents can be established. This article will describe the clinical signs that can occur from common ingredients in cleaning agents and outline the treatment recommendations for managing cases of exposure.
| Ingredients | Type of compound |
|---|---|
| Benzalkonium chloride | Cationic detergent and quaternary ammonium compound (QAC) |
| Benzisothiazolinone | Isothiazolinone |
| Citric acid | Weak acid |
| Hydrochloric acid | Strong acid |
| Lactic acid | Weak acid |
| Methylchloroisothiazolinone | Isothiazolinone |
| Methylisothiazolinone | Isothiazolinone |
| Potassium hydroxide (caustic potash) | Strong alkali |
| Sodium hydroxide (caustic soda) | Strong alkali |
| Sodium hypochlorite | Chlorine bleach |
| Sodium lauryl sulphate | Anionic detergent |
| Sodium percarbonate | Oxygen-based bleach |
Detergents and soaps
A detergent is any substance that reduces the surface tension of water; more specifically, it is a surface-active agent (surfactant) that concentrates at oilwater interfaces and possesses emulsifying and, thus, cleansing properties. Detergents are present in a wide variety of household products and are usually listed on the container as anionic, non-ionic or cationic surfactants.
The severity of clinical signs will depend on the quantity, concentration, duration of contact and type of detergent involved. Anionic (e.g. sodium lauryl sulphate) and non-ionic surfactants (e.g. polyoxyethylene alkyl ethers) are of low systemic toxicity. They are irritant to the gastrointestinal tract and may cause vomiting or diarrhoea if ingested. Non-ionic detergents, however, are generally less irritating than anionic detergents (Gloxhuber, 1974).
Traditional soap bars are based on fatty acids (from animal or vegetable sources), which are saponified (turned into soap) by reaction with alkali. There is some residual alkali in soap that may enhance irritation; this will be more marked with old fashioned household soaps for cleaning clothes than soaps used for washing skin.
Ingestion of a detergent-containing product may cause hypersalivation, frothing or foaming at the mouth, retching, vomiting, diarrhoea, inappetence and hyperthermia. Occasionally, there may also be oral irritation, ulceration and glossitis (inflammation of the tongue). Respiratory complications include coughing, abnormal lung sounds and dyspnoea. Aspiration is a potential risk (Osweiler et al, 2011) which may occur after ingestion or if vomiting occurs, as the vomitus may be frothy. Aspiration can result in chemical pneumonitis but it is rarely reported (Veterinary Poisons Information Service (VPIS), unpublished data). In the eye, detergents can cause irritation with conjunctival hyperaemia and, in severe cases, corneal oedema and ulceration.
Cats are much more likely to develop respiratory complications and dermal effects than dogs (VPIS, unpublished data), possibly owing to their grooming behaviour where they ingest detergents on their coat and damage skin further with repeated licking. Anionic and non-ionic detergents are also irritant to the skin and can cause erythema, inflammation and dermatitis; if dermal decontamination is delayed, there may be burns, alopecia, oedema and skin sloughing (VPIS, unpublished data).
Fabric washing capsules
Liquid detergent capsules (also called liquid capsules, liquid sachets or laundry pods) for washing machines are a particular hazard. They are small, soft, bitesized capsules, containing concentrated detergent and they burst easily when wet or bitten.
Most canine exposures to laundry cleaning detergents reported to the author's organisation, the VPIS, involve detergent capsules, rather than washing powders or liquids (Bates and Edwards, 2014a). Ingestion of detergent capsules typically causes gastrointestinal and respiratory signs (Bates and Edwards, 2014a; Forrester, 2014). Common clinical signs after ingestion are vomiting, coughing, frothing at the mouth and retching. This is similar to cases reported in humans, particularly children (Williams et al, 2014). There is also a risk of aspiration pneumonia. Skin burns may result from dermal exposure, particularly if liquid is not removed promptly, and corneal ulceration may result if splashed into the eye (Bates and Edwards, 2014a).
Disinfectants
Cationic detergents (e.g. quaternary ammonium compounds (QACs)) are mainly used as disinfectants rather than simple cleaning agents like anionic and non-ionic detergents. The most common QAC in household products is benzalkonium chloride (often referred to as BAC) and it is found in disinfectant liquid and wipes, antiseptic cleaners, patio cleaners and automatic hand-soap dispensers. It is also a common preservative in pharmaceutical preparations including ear and eye drops and nasal sprays.
Benzalkonium chloride has been shown to interact with proteins and lipids in biological membranes (Patarca et al, 2000) and cause immuno-inflammatory reactions (Baudouin et al, 2010). Although concentration is generally low in household disinfectants they pose a significant hazard to pets, particularly cats.
Common signs on presentation are hypersalivation or drooling, buccal irritation, tongue and oral ulceration, hyperthermia and inappetence. There may also be depression, vomiting, glossitis and respiratory signs. In a review of 245 feline cases reported to the VPIS, the median recovery time was 72 hours (Bates and Edwards, 2014b). Dermal exposure may cause erythema, inflammation, ulceration, hair loss and contact dermatitis, and concentrated solutions may cause chemical burns. Ocular exposure may result in irritation and inflammation. Burns to the eye may occur, particularly with concentrated solutions.
It is important to note that in many cases of benzalkonium chloride exposure, animals present late as signs may be absent initially. Benzalkonium chloride exposure should be suspected in any cat that presents with hyperthermia, hypersalivation and ulceration of the tongue, and owners should be asked about the use of disinfectants, patio cleaners and other household products that can contain benzalkonium chloride.
Bleach
The term bleach may refer to products containing sodium hypochlorite or, much less commonly, hydrogen peroxide or other oxygen ‘donors’. Products containing sodium hypochlorite are often described as containing ‘active chlorine’, whereas those based on hydrogen peroxide contain ‘active oxygen’.
Chlorine-based bleach
Sodium hypochlorite is used as a general disinfectant and bleaching agent. It is also found in some mould and mildew removers. Household sodium hypochlorite bleaches are usually solutions up to 10.0% but are rarely more than 5.0%. These solutions often contain other agents including sodium hydroxide to maintain a pH-dependent equilibrium between hypochlorite and chlorine. Industrial bleaches are more concentrated (up to 50.0%).
Sodium hypochlorite solution causes moderate mucosal irritation, the extent of which depends on the volume ingested, the viscosity and concentration and the duration of contact. Although sodium hypochlorite solution is alkaline, it does not tend to cause corrosive damage except following ingestion of a large quantity or a concentrated solution; deaths in humans often involve ingestion of a large quantity.
Most cases occur in dogs and cats, although poisoning may also occur in birds (McKnight, 2004). Clinical effects are the same in all animals, but birds are more sensitive to the fumes of cleaning products (Wilson et al, 2001; McKnight, 2004). Common signs in animals exposed to chlorine-based bleach include hypersalivation, vomiting, lethargy and inappetence. Oral and tongue ulceration occurs in some cases. Less common effects include diarrhoea, polydipsia and respiratory distress. Severe toxicity is rare (Coppock et al, 1988).
Corrosive injury to the oesophagus and stomach can occur with sodium hypochlorite bleach but the incidence is low. Hypernatraemia, hyperchloraemic acidosis and increased serum osmolality were reported after ingestion of a large quantity of a 6.5% solution in dogs (Chapman et al, 2008). Dermal exposure can cause skin irritation with erythema and oedema. Bleaching of fur may also occur (Richardson, 2004).
Oxygen-based bleach
Oxygen-based bleaches are available as liquid hydrogen peroxide or products containing sodium percarbonate. The latter is a powder made of sodium carbonate and hydrogen peroxide and is found in stain removers and laundry powders. When mixed with water, percarbonates break down into sodium carbonate and hydrogen peroxide. It is the latter that lifts dirt and stains. Hydrogen peroxide is also used for bleaching hair and is present in some hair colourants. Dermal contact will bleach fur.
These products are irritant and cause hypersalivation, retching, vomiting and inappetence. Abdominal discomfort may occur and there is a risk of tongue or oral ulceration and haemorrhagic diarrhoea.
Hydrogen peroxide 3.0% is used as an emetic in veterinary medicine and induces a vomiting reflex through irritant effects on the oropharynx and gastric lining. Lethargy and protracted vomiting have been reported in dogs after the use of hydrogen peroxide as an emetic (Khan et al, 2012). Hydrogen peroxide can cause local tissue damage with haematemesis and gastritis, particularly with excessive dosing in cats (Lee, 2013).
In the presence of organic matter, hydrogen peroxide vigorously decomposes to oxygen and water and the oxygen produced can cause emboli. This has occurred in humans after ingestion of hydrogen peroxide (Cina et al, 1994) but poses a higher risk in higher concentrations (e.g. 30.0–40.0%).
Corrosives
Some cleaners contain corrosive compounds (i.e. acids or alkalis). Alkalis and acids can be described as strong or weak; this does not refer to their concentration, however, but to their chemical behaviour in water. Strong acids and alkalis dissociate (ionize) completely in water, whereas weak acids and alkalis only partially dissociate.
Strong alkalis such as sodium hydroxide (caustic soda) or potassium hydroxide (caustic potash) are found in oven cleaners and some drain cleaners. Strong acids (e.g. hydrochloric acid, sulphuric acid) are also found in some drain cleaners. Sodium hydroxide and hydrochloric acid are also available as the pure compounds themselves. Kettle descalers also contain acids but, often, these are weak acids (e.g. lactic acid, citric acid) and these are irritant rather than corrosive, especially after they have been used, as the ‘scale’ will neutralise the acid. Detergents are alkali but they are irritant rather than corrosive. It is the strong acids and strong alkalis that are considered most hazardous.
Alkalis cause liquifactive necrosis with saponification of fats and solubilisation of proteins; they are also hygroscopic and will absorb water from the tissues. These effects result in adherence and deep penetration into tissue. In contrast, acids cause coagulative necrosis and the coagulum can hinder further penetration of the acid and may protect deeper tissues, although, in severe cases, deep burns and perforation may occur.
Alkalis cause the most severe corrosive effects on the oesophagus, whereas ingestion of acids tends to result in more severe injury to the stomach. However, after ingestion of a large quantity of an alkali, both the stomach and small intestine may be involved. The severity of injury will depend on a number of factors:
Ingestion of a corrosive cleaner can cause hypersalivation, oral inflammation or ulceration, with swelling of the lips. This is followed by vomiting, haematemesis, ulcerative mucosal burns and dyspnoea. Acute complications include gastrointestinal haemorrhage, perforation of the gut and upperairway obstruction. However, most cases in pets involve licking of used or spilled product, so the amount ingested is often small. Dermal exposure is more common and, on the skin, alkalis can cause deep penetrating burns and necrosis. There may be alopecia, erythema, blisters, pain, ulceration and oedema. Burns from acids tend not to be so deep but they can still cause erythema and blistering. Alkali burns can initially be painless but can progress over a few hours. Ocular burns can also occur and can be serious if an alkali is involved.
Other ingredients
In addition to their active ingredients, cleaners may also contain perfumes, colourants and preservatives but these generally do not contribute to their toxicity. Some constituents are in ingredient lists because they can cause sensitivity reactions in some people, not because they are toxic.
Isothiazolinone derivatives, such as methylisothiazolinone, methylchloroisothiazolinone or benzisothiazolinone, are widely used as biocidal preservatives in many household cleaners, toiletries, cosmetics and even paints. Although they are corrosive, this is generally not a concern with household products because they are present in low concentrations. They may, however, contribute to the irritant effects of the product. Isothiazolinone derivatives are known to cause skin sensitisation in humans resulting in contact allergy and allergic contact dermatitis (and so will be highlighted in ingredient lists).
Polycarboxylates are commonly used in laundry and dishwasher detergent products to enhance performance and help disperse dirt. They are present in a low concentration (<1.0%) and are unlikely to present a toxicological hazard.
Treatment of animals with exposure to cleaners
Emesis and gastric lavage are contraindicated after ingestion of a detergent-containing product because of the risk of aspiration. Activated charcoal is ineffective and not recommended (Osweiler et al, 2011). Treatment is essentially symptomatic and supportive with rehydration and an antiemetic, if required. If an animal has suspected aspiration (i.e. is coughing, wheezing or has tachypnoea), the lung sounds should be checked and, if indicated, a baseline chest x-ray should be performed.
After recent exposure to a product containing benzalkonium chloride, it is essential to ensure the oral cavity is thoroughly washed and decontaminated. Atropine may be given for hypersalivation if required. Rehydration and gastroprotectants (e.g. H2 blockers, sucralfate), may be required and a bland diet is recommended. Analgesia should be given as required, as these products can cause significant oral ulceration that takes days to heal. In animals with severe oral signs, syringe or nasogastric feeding may be necessary, although in 245 cases, this was only necessary in 13 cats (Bates and Edwards, 2014b).
After dermal exposure to a cleaning product, the affected area should be thoroughly rinsed with water to ensure prompt decontamination. A collar should be considered to prevent grooming. Any signs of irritation should be managed conventionally. Affected eyes should be thoroughly irrigated with saline or water and stained with fluorescein to assess any injury. Sedation and/or anaesthetic drops may be required to facilitate this and allow thorough decontamination.
All animals exposed to a strong acid or alkali should be assessed and observed for progression of injury. It is important to note that although signs of mucosal damage are expected to start within 4 hours, it may take several hours for the full extent of the injury to become evident. Emesis is contraindicated after ingestion of an acid or alkali because of the risk of further injury on re-exposure of the oesophagus. Activated charcoal has no role in acid or alkali ingestion (Fulton and Rao, 2006) and would compromise endoscopic examination if it should be required later (Chyka et al, 2005). Oral fluids may be given unless there is evidence of severe injury or suspicion of perforation. Neutralising chemicals should never be given following exposure to an acid or an alkali, because heat is produced during neutralisation and this could exacerbate any tissue injury.
Endoscopic evaluation may be required to assess the extent and severity of the injury and therapy should include analgesia and gastroprotectants, intravenous fluids for shock and feeding support. Ventilation may be required in animals with airway compromise. Following dermal exposure, acid should be thoroughly washed from any exposed skin. Care should be taken to prevent exposure of other areas with the run-off fluid. With alkalis, prolonged copious irrigation is recommended (O'Donoghue et al, 1996) as this cleanses the wound of unreacted chemical, dilutes the chemical already in contact with tissue, and restores tissue water lost to the hygroscopic effect of alkalis.
If possible, pH of the skin or eye and irrigating fluid should be monitored. A urinalysis strip or universal indicator paper can be used for this and is helpful to determine the effectiveness of decontamination. It is recommended that 15 minutes elapse before checking the pH of the skin to allow residual alkali to diffuse up from the deeper regions of the dermis (Herbert and Lawrence, 1989; O'Donoghue et al, 1996).
Sedation or anaesthesia may be required to facilitate thorough decontamination. After decontamination, any skin injury, such as irritation or burns, should be managed supportively. After irrigation of the eye, further treatment is aimed at preventing optic nerve damage from raised intraocular pressure and to protect the cornea from ulceration, perforation and infection. In severe cases, referral to a veterinary ophthalmologist may be required.
Conclusions
Exposure to cleaning products typically causes only mild gastrointestinal, skin or respiratory signs but it is important to determine the type of product involved, the potential risks and the most appropriate treatment. More significant signs are seen after exposure to products containing benzalkonium chloride, particularly in cats, or corrosive compounds and after inadequate dermal decontamination of detergent products. In these cases, presentation is often delayed and where the cause of illness is not immediately apparent, it is worthwhile questioning the owner on possible exposure to cleaning products. Emesis is contraindicated after ingestion of most cleaning products and activated charcoal is not recommended. Therefore treatment is symptomatic and supportive after thorough decontamination.