Pediatric Annals

The Nontoxic Ingestion

Gary S Wasserman, DO

Abstract

I became interested in toxicology the first day of my pediatric residency in 1971. I was working in the emergency department where the poison control center was located. I answered a telephone call from an anxious parent whose toddler had ingested the liquid inside a golf ball. Dr Jay Arena's textbook on poisoning1 cited water, glycerin, or polyethylene glycol as the pressurized fluid core of a golf ball. Isn't it fascinating how such a minor event would influence a career? Our poison center is still located in the emergency department, and a physician talks to all callers. Our residents, nurses, and students quickly learn that the majority of ingestions involve children younger than 6 years of age and that children will put anything they can get their hands on into their mouths. The staff also learn that approximately 75% of accidental ingestions in young children are nontoxic. The "nontoxic" incident is defined as an exposure to a substance that is not dangerous to life or injurious to health in the amount ingested as determined by worst case scenario from the history.

Nontoxic ingestions are common and can serve as a warning about risk for a more serious poisoning. According to 1993 data from the Toxic Exposure Surveillance System (TESS) of the American Association of Poison Control Centers, 56% of the 1,751,476 human exposures to poison occurred in children younger than 6 years of age with 42% occurring in children younger than 3 years of age.2 Incidentally, there were 137 exposures to golf balls. In those younger than 6 years of age, 94% of exposures were classified as either no/nontoxic or minor/minimal effect/toxic ity. Repeaters are common among both toxic and nontoxic ingestions. A study of 1943 ingestions in children younger than 6 years of age revealed that 30.1% had experienced a prior poison exposure.3 Most repeaters (68.9%) experienced only one prior ingestion, but the range of repeated ingestions was 1 to 15. Therefore, ingestion of even a nontoxic substance should serve as a warning that the child's environment has not been made poison-proof, and that the child needs closer supervision before a tragic poisoning occurs.

Three simple "tools" help distinguish nontoxic from toxic ingestions. The first is a way to estimate dose. It has been calculated that the volume of a swallow (not gulp) is 0.21 mL/kg, or one teaspoon (4.5 mL), for a child 18 months to 3 years old, and 15 mL for an adult.4 Second is the product label. Signal words such as danger, caution, warning, or poison, or the listing of a specific antidote or statement to "call physician immediately" should automatically remove this product from the category of simple nontoxic exposure.5'7 "Keep out of the reach of children" stated on a product has no significance since many products with minimal potential for toxicity have this on the label for liability reasons. The product packaging can be helpful in determining the potential for a toxic ingestion. Squeeze tubes, pump containers, spray aerosol cans, and small promotional samples will rarely yield a toxic amount. The third tool is the condition of the child. If the ingestor has any symptoms, even if the symptoms are unrelated to the ingrethents of the product or the ingrethents are "nontoxic", a medical evaluation or repeat telephone follow-up is necessary to exclude a toxic ingestion.

According to Mofenson et al,8 the following criteria are required to designate a "nontoxic ingestion":

* absolute identification of the product has been made,

* the time and amount of the ingestion is known,

* the amount ingested, relative to the patient's weight, is less than the…

I became interested in toxicology the first day of my pediatric residency in 1971. I was working in the emergency department where the poison control center was located. I answered a telephone call from an anxious parent whose toddler had ingested the liquid inside a golf ball. Dr Jay Arena's textbook on poisoning1 cited water, glycerin, or polyethylene glycol as the pressurized fluid core of a golf ball. Isn't it fascinating how such a minor event would influence a career? Our poison center is still located in the emergency department, and a physician talks to all callers. Our residents, nurses, and students quickly learn that the majority of ingestions involve children younger than 6 years of age and that children will put anything they can get their hands on into their mouths. The staff also learn that approximately 75% of accidental ingestions in young children are nontoxic. The "nontoxic" incident is defined as an exposure to a substance that is not dangerous to life or injurious to health in the amount ingested as determined by worst case scenario from the history.

Nontoxic ingestions are common and can serve as a warning about risk for a more serious poisoning. According to 1993 data from the Toxic Exposure Surveillance System (TESS) of the American Association of Poison Control Centers, 56% of the 1,751,476 human exposures to poison occurred in children younger than 6 years of age with 42% occurring in children younger than 3 years of age.2 Incidentally, there were 137 exposures to golf balls. In those younger than 6 years of age, 94% of exposures were classified as either no/nontoxic or minor/minimal effect/toxic ity. Repeaters are common among both toxic and nontoxic ingestions. A study of 1943 ingestions in children younger than 6 years of age revealed that 30.1% had experienced a prior poison exposure.3 Most repeaters (68.9%) experienced only one prior ingestion, but the range of repeated ingestions was 1 to 15. Therefore, ingestion of even a nontoxic substance should serve as a warning that the child's environment has not been made poison-proof, and that the child needs closer supervision before a tragic poisoning occurs.

Three simple "tools" help distinguish nontoxic from toxic ingestions. The first is a way to estimate dose. It has been calculated that the volume of a swallow (not gulp) is 0.21 mL/kg, or one teaspoon (4.5 mL), for a child 18 months to 3 years old, and 15 mL for an adult.4 Second is the product label. Signal words such as danger, caution, warning, or poison, or the listing of a specific antidote or statement to "call physician immediately" should automatically remove this product from the category of simple nontoxic exposure.5'7 "Keep out of the reach of children" stated on a product has no significance since many products with minimal potential for toxicity have this on the label for liability reasons. The product packaging can be helpful in determining the potential for a toxic ingestion. Squeeze tubes, pump containers, spray aerosol cans, and small promotional samples will rarely yield a toxic amount. The third tool is the condition of the child. If the ingestor has any symptoms, even if the symptoms are unrelated to the ingrethents of the product or the ingrethents are "nontoxic", a medical evaluation or repeat telephone follow-up is necessary to exclude a toxic ingestion.

According to Mofenson et al,8 the following criteria are required to designate a "nontoxic ingestion":

* absolute identification of the product has been made,

* the time and amount of the ingestion is known,

* the amount ingested, relative to the patient's weight, is less than the smallest amount known or predicted to induce toxicity,

* the time elapsed since the ingestion is greater than the longest predicted interval between ingestion and toxicity, and

* a detailed history has been obtained with no signs or symptoms of toxicity.

Stated yet another way, a nontoxic ingestion occurs when a person consumes a nonedible product that does not cause symptoms. Remember that no chemical agent is entirely safe if ingested in a large amount. Unfortunately, the term "large amount" is vague and not well defined.

It is important to identify ingestions that are nontoxic. By doing so, one can avoid the risks and inmision of the treatments used to remove the ingested material and the wasted professional time and money dealing with the incident. The National Poisons Information Service (NPIS) in the United Kingdom designed a poster listing nontoxic substances and distributed it to all accident and emergency departments.9 Instead of contacting the NPIS, 70% of the accident and emergency departments indicated they would use the poster. The poster lists three major categories:

* plants (possibility of causing mild gastrointestinal upset or mild dermatitis),

* drugs, and

* household and garden products (cleaners, cosmetics, paints and glues, garden, and miscellaneous).

The most popular chart of nontoxic ingested substances was conceived by Mofenson et al (Table I).5,6,8

A common generalization is that a young healthy child should be able to tolerate the documented ingestion of a single adult dose of a medication (tablet, capsule, or teaspoon) without significant toxicity. From 1983 to 1989, seven drug groups accounted for almost half of all fatalities in children younger than 3 years of age: camphor, antimalarias, methyl salicylate, phenothiazines, quinine, theophylline, and cyclic antidepressants (Table 2).10 However, there are exceptions among the most toxic drugs. These are the medicinal preparations that can be fatal to a 10-kg toddler upon ingestion of one to two tablets, capsules, or teaspoons. The following should be added to this list: opioids (including diphenoxylate), cardiovascular agents (clonidine, calcium channel blockers, and beta-blockers), hypoglycemic sulfonylureas, and podophyllum. Also, a little more than 1 mL of the decongestant imidazoline derivatives found in nose/eye drop/spray (ie, Afrin and Visine) may cause central nervous system depression.11

COMMON SUBSTANCES ACCIDENTALLY INGESTED BY CHILDREN

At Children's Mercy Hospital, Kansas City, Missouri, we developed a chart of the more common substances accidentally ingested by children based on calls made to our poison center (Figure). This chart became nicknamed the "Poisonpal," "Ingestidex," or "Toxitard" and was helpful for at least 70% of poison control center calls. The purpose of the information was to serve as a quick guide in determining whether a substance was nontoxic versus potentially toxic. The following guidelines help in this distinction.

Analgesics

Over-the-counter analgesics (acetaminophen, salicylate, and Ibuprofen) are all nontoxic at < 100 mg/kg.

Antibiotics

The main antibiotics, penicillins and cephalosporins, are relatively safe at <250 mg/kg. The acute single ingestion of oral antibiotics in general is considered nontoxic unless massive doses are involved.

Table

TABLE 1The Usually Nontoxic Ingestion (Unless Ingested In Very Large Amounts)*

TABLE 1

The Usually Nontoxic Ingestion (Unless Ingested In Very Large Amounts)*

Table

TABLE IThe Usually Nontoxic Ingestion (Unless Ingested In Veiy Large Aniounts)*

TABLE I

The Usually Nontoxic Ingestion (Unless Ingested In Veiy Large Aniounts)*

Antihistimines and Decongestants

For antihistamines and decongestants, the equivalent of two daily doses is used as the cutoff point. An exception to this is diphenhydramine, which uses a cutoff point of one daily dose.

Antitussives

Antitussives are insignificant if <5 mg/kg of dextromethorphan or 3 mg/kg of codeine are involved.

Alcohol and Glycols

More than a few licks of methanol or ethylene glycol may be lethal, while isopropanol is potentially toxic at 0.25 mL/kg and ethanol at 0.5 mL/kg.

Caffeine

Caffeine in stimulants, analgesics, cold medications, soft drinks, coffee, teas, and weight control products is considered safe in doses <15 mg/kg.12 Cola and related beverages contain 30 to 60 mg of caffeine per 12-oz serving while a 5-oz cup of coffee ranges from 30 to 180 mg, and 5 oz of tea ranges from 20 to 110 mg.13

Nicotine

Nicotine, the pharmacologically active ingrethent in tobacco, is a potent poison. However, ingestion of cigarettes and cigarette butts by children is generally benign. A large case series of 700 children younger than 6 years if age who ingested cigarettes or butts revealed only 20.4% had symptoms. Vomiting was the only symptom in 98.6% and it occurred in less than 20 minutes after ingestion in 74.3%. 14 This early selfdecontamination helps prevent toxic sequelae. The absence of vomiting generally predicts a favorable outcome. Even though 1-2 cigarettes, or 3-6 cigarette butts, contain a potentially toxic dose of nicotine. The nicotine content is only one factor - the tobacco formulation and pH of the preparation also determine the amount of available toxin.

Cosmetics

Cosmetics are generally safe items. However, remember that perfumes, colognes, and toilet waters contain ethanol. Permanent wave or hair straightener solutions may be caustic (alkaline). Nail polish remover contains either acetone, isopropanol, ethanol, or ethyl acetate, and sculptured nail remover is potentially lethal in any amount because it contains acetonitrile, which converts to cyanide. Fluoride in the form of vitamins or dental products is nontoxic under 3 mg/kg.

Hydrocarbons

Hydrocarbons are common in industrialized societies, and they are one of our top 10 etiologies for admission secondary to a toxic exposure. Toxicity is almost always due to pneumonitis. It is unlikely that a small child will accidentally drink enough of a household hydrocarbon to cause concern about systemic effects. The most popular are lamp oils since they are often colored and contain a fragrance. Gasoline, kerosene, furniture polish (mineral seal oil), or turpentine are also common. Heavy hydrocarbons such as fuel oil, mineral oil, diesel oil, asphalt, and lubricating oil are rarely aspirated or absorbed from the gastrointestinal tract. In the absence of immediate symptoms of gagging, choking, vomiting, syncope, or respiratory symptoms of apnea, coughing, or wheezing, the child is unlikely to need medical care and can be safely monitored at home. If symptoms later occur such as coughing, wheezing, dyspnea, or lethargy, then a medical evaluation is necessary. Of course dependable parents are important when observing these children at home.

Table

TABLE 2Medicinal Preparations Which Can Be Fatal to a ??-kg Toddler Upon Ingestion of One to TMfO Tablets, Capsules, or Teaspoonfuls*

TABLE 2

Medicinal Preparations Which Can Be Fatal to a ??-kg Toddler Upon Ingestion of One to TMfO Tablets, Capsules, or Teaspoonfuls*

Hydrogen Peroxide

The 3% concentration of hydrogen peroxide traditionally used as an antiseptic for cuts produces oxygen and water, but concentrated preparations >10% may result in caustic injury.15

Iron

Elemental iron is considered safe at <20 mg/kg.

Mothballs and Deodorizers

The most commonly purchased mothballs and toilet bowl and diaper pail deodorizer cakes are paradichlorobenzene: one to two mothballs are considered safe. While more than one naphthalene-type mothball may be toxic, any amount of the camphor variety is potentially dangerous. Liquid may collect at the base of some wick deodorizers and should be nontoxic in this volume unless aspiration and chemical pneumonitis occurs. In general, these products contain water, surfactant, and perfume.

Plants

The plant category is too large to discuss in this review. I choose to avoid short lists of so-called nontoxic plants because of geographic differences and because many household plant names often overlap different scientific names. In general, most indoor house plants (airplane, aloe, dracaena, fern, jade, palm, poinsettia, pussy willow, schefflera, spider, Swedish ivy, wandering Jew, and yucca) are nontoxic or only mildly toxic, causing mucous membrane irritation secondary to calcium oxalate crystals (caladiums, dieffenbachia, dumbcane, mother-in-law's tongue, and philodendrons). Many outdoor plants and berries are toxic and need to be checked. As a general rule, plants closely related botanically usually have similar toxic properties.

Rodenticides

The anticoagulant types of rodenticides (short-acting warfarin and long-acting "super warfarins") take, sometone ingesting quite a few chunks or mouthfuls to exceed a typical equivalent heparin- or coumadinloading dose.

Household Cleaners

Soaps, detergents, and general purpose cleaners are of low-order toxicity and act primarily as irritants. The addition of bleaching agents, antibacterial agents, coloring agents, enzymes, surfactants, and softeners contribute little to toxicity. Common household bleach of 5% to 6% sodium hypochlorite rarely causes esophageal injury.16,17 However, industrial bleaches contain sodium peroxide, sodium perborate, sodium carbonate, or oxalic acid, usually at a higher pH and concentration than household bleach and therefore are more caustic. Electric dishwasher soap is usually alkaline (sodium carbonate, trisodium phosphate, sodium metasilicate, and sodium tripolyphosphate), and caustic damage must be considered.

Table

Figure. The Children's Mercy Hospital Poison Control Center's Quick Guide for Ingestion by Young Children.

Figure. The Children's Mercy Hospital Poison Control Center's Quick Guide for Ingestion by Young Children.

Table

Figure. The Children's Mercy Hospital Poison Control Center's Quick Guide for Ingestion by Young Children.

Figure. The Children's Mercy Hospital Poison Control Center's Quick Guide for Ingestion by Young Children.

Miscellaneous

Broken thermometers are a concern for trauma from the glass, but the amount of mercury or red/blue colored alcohol is insignificant. It requires a large number of one-a-day multivitamins (without iron) to exceed 75,000 IU of vitamin A, 40,000 IU of vitamin D, or 100 mg of niacin to be concerned.

Antacids contain aluminum carbonate, aluminum hydroxide, aluminum phosphate, calcium carbonate, magnesium carbonate, magnesium hydroxide, magnesium oxide, or magnesium trisilicate, sometimes in combination with simethicone, an antigas agent. Large acute ingestions of antacid can cause mild gastronitestinal irritation, but are well tolerated and considered nontoxic.

Art and Writing Supplies

The majority of art and writing materials are in liquid form while the remainder are usually in a hard cylinder form. It is unusual for the accidental ingestor to eat or swallow more than a bite or two of these items. Often, the child is discovered with color on his or her hands, indicating only licking of the material. Inks containing aniline (such as dyes and shoe blacks) may cause methemoglobinemia, but the typical ballpoint pen, porous tip or flow marker, or ink cartridge do not contain enough solvents, glycols, alcohols, pigments, mineral acids, formaldehyde, etc, to be of serious concern. Pencils contain graphite and rarely contain lead. Colored pencils have small amounts of toxic pigments, but not enough to be hazardous. Crayons contain nontoxic pigments, paraffin, and stearic acid, although some foreign crayons may be contaminated with lead. In accordance with designation by the US Department of Commerce, nontoxic crayons are labeled "CP," "AP," or "CS 130-46." Chalk, whether colored or white, contains calcium carbonate and kaolin or limestone and is nontoxic.

Modeling clay, water soluble pastes and glues, and paints intended to be used for school children are usually nontoxic. Adult materials may be hazardous; rubber, plastic, and other household model cements contain volatile hydrocarbons such as toluene, benzene, and xylene and represent an aspiration hazard or can cause central nervous system depression, especially if inhaled in a poorly ventilated area. Cyanoacrylate adhesives, known as "super glue," are unlikely to cause acute symptoms when ingested.

Artist oil paints may contain high concentrations of heavy metals as pigments yielding brilliant colors such as arsenic-Paris (emerald) green, lead chromate-yellow, orange, white, and chromium-green. Water colors and poster paints containing 50% to 60% pigment may be dangerous and require evaluation for gastrointestinal decontamination. In general, a bite or swallow of these toxic pigmented materials is not poisonous.

Matches and Caps

These would have to be consumed in the volume of many match books or rolls of caps to yield a toxic amount of potassium chlorate.

CONCLUSION

This article reviews some of the most common nontoxic household items exposed to children. There are few research studies that help predict when an ingestion is truly nontoxic. Poison control centers need to obtain data on all ingestions to generate large numbers to better define the nontoxic exposures. A more scientific understanding of the nontoxic ingestion will prevent unnecessary visits to health-care facilities, prevent overtreatment and laboratory utilization, and better prepare physicians and poison centers to teach poison prevention.

REFERENCES

1. Arena JM. Poisoning. Toxicology-Symptoms-Treatment. 2nd ed. Springfield, Hl: Charles C Thomas Publisher, 1970.

2. Litovitz TL. Clark LR, Soloway RA. 1993 annual report of The American Association of Poison Control Centers Toxic Exposure Surveillance System. Am J Emerg Med. 1994;12:546-584.

3. Litovitz TL, Flagler SL, Manoguerra AS, et al. Recurrent poisonings among pediatric poisoning victims. Mettcal Toxicology and Adverse Drug Experience. 1989;4:381-386.

4. Jones DV, Work CE. Volume of a swallow. Am J Dis Child. 1 964; 102:427.

5. Mofenson HC, Greensher J. The nontoxic ingestion. Pediatr Clin North Am. 1970;17:583-590.

6. Mofenson HC, Greensher J, Caraccio TR. Ingestions considered nontoxic. Emerg Med Clin North Am. 1984;2:159-174.

7. Goseelin RE, JAMA. 1967:163:1333.

8. Update on pediatric poisonings. Poison Perspectives for Health Professionals. 1995;14:1-4.

9. Morgan IEJ, Bates NS. A survey into the perceived usefulness of the NPIS poster "A Guide to Commonly Ingested Non-Toxic Substances,' Vet Hum Toxicol. 1993;35:303-306.

10. Koren G. Medications which can kill a toddler with one tablet or teaspoonful. Clin Toxicol. 1993;31:407-413.

11. Klein-Schwartz W, Gorman R, Oderda GM, et al. Central nervous system depression from ingestion of non-prescription eyedrops. Am J Emerg Med. 1984;2:217-218.

12. McGee D, Brabson T, McCarthy J, et al. Four-Year review of cigarette ingestions in children. Pediatr Emerg Care. 1995;11:13-16.

13. Ellenhom MJ, Bareeloux DG. Over-the-counter products. In-. EUenhom MJ, Barcebux DG, eds. Medical Toxicology-Diagnosis and Treatment of Human Poisoning. 1st ed. New York, NY: Elsevier, 1988:509.

14. Walsh I, Wasserman GS, Mestad P, Lanman R. Near fatal caffeine intoxication treated with peritoneal dialysis. Pediotr Emerg Core. 1987;3:244-249.

15. Dickson KF, Caravati EM. Hydrogen peroxide exposure - 325 exposures reported to a regional poison control center. CIm Toxicol 1994;32:705-714.

16. Pike DG, Peabody JW, Edgar ET, et al. A re-evaluation of the dangers of Clorox ingestion. J Pediatr. 1963;63:303.

17. Rodgers GC, Matyunas NJ. Handbook of Common Poisonings in Children. 3rd ed. Elk Grove Village, III: American Academy of Pediatrics; 1994.

TABLE 1

The Usually Nontoxic Ingestion (Unless Ingested In Very Large Amounts)*

TABLE I

The Usually Nontoxic Ingestion (Unless Ingested In Veiy Large Aniounts)*

TABLE 2

Medicinal Preparations Which Can Be Fatal to a ??-kg Toddler Upon Ingestion of One to TMfO Tablets, Capsules, or Teaspoonfuls*

Figure. The Children's Mercy Hospital Poison Control Center's Quick Guide for Ingestion by Young Children.

Figure. The Children's Mercy Hospital Poison Control Center's Quick Guide for Ingestion by Young Children.

10.3928/0090-4481-19960101-09

Sign up to receive

Journal E-contents