A facility recently submitted the following report to PA-PSRS:

A patient was to receive iontophoresis with acetic acid in a hospital-affiliated, off-site Physical Therapy department. Prior to the treatment, the therapist applied an acetic acid-soaked patch to the patient’s skin. The patient immediately complained of burning, in response to which the therapist immediately removed the patch. Underneath, the patient had a reddened, raised skin area that was exactly the size of the iontophoresis patch. The therapist washed the area and notified Pharmacy. At the pharmacist’s recommendation, the therapist applied sodium bicarbonate to the affected area. The patient sustained a first degree burn with skin discoloration and minor scarring. Glacial acetic acid had been dispensed by the hospital pharmacy instead of a 10% solution. The bottle sent to the Therapy Department was labeled as a 10% concentration.

What is Glacial Acetic Acid?

Glacial acetic acid is a 99.5-100% concentration of acetic acid. The term “glacial” refers to its property of forming crystals at 17 degrees Celsius (62.6 degrees Fahrenheit)—giving it the appearance of being frozen, like a glacier.¹ Glacial acetic acid is a poisonous and corrosive liquid that may cause severe burns to tissue. If swallowed, it can result in perforation of the esophagus or death. Lung and tooth damage can occur if the product is inhaled. Eye contact may result in severe eye damage, including loss of sight.²

Medical Uses of Glacial Acetic Acid

Undiluted glacial acetic acid has no medical use, but diluted formulations of acetic acid are used for treatments such as iontophoresis, bladder and wound irrigations, treatment of ear canal/outer ear infections, and during colposcopy to identify cervical dysplasia.¹

Investigation

The facility’s investigation uncovered many factors that may have contributed to this error. Ordinarily, the facility uses dexamethasone for iontophoresis procedures. Following this typical practice, a pharmacy student compounded dexamethasone for iontophoresis on the Friday before the patient’s Monday treatment. However, because this patient was allergic to steroids, the physician ordered acetic acid instead.The Physical Therapy department sent a request (not the physician’s order) to pharmacy for “acetic acid for iontophoresis” with no concentration specified. On Monday, a pharmacist discovered that the acetic acid solution had not been prepared. A recently graduated pharmacist rushed to get the acetic acid ready in time for a courier to pick up and transport it to the off-site therapy department. He poured some glacial acetic acid from a larger bottle, located in the compounding area, into a smaller brown bottle and labeled it 10%. While the Pharmacy has a compounding book which contains a description of how to perform the dilution, the pharmacist did not refer to it. At the time, there was no double check system for preparing and dispensing acetic acid.

The label on the larger glacial acetic acid bottle clearly indicated both the concentration and the deleterious health effects of exposure to the product (see Figure 1). While the pharmacist is aware of the poisonous, corrosive nature of glacial acetic acid, he does not know why he dispensed undiluted glacial acetic acid. The pharmacy director indicated that the facility does not use glacial acetic acid for any purpose other than for diluting it for medical treatments.

  Figure 1. Label on Undiluted Bottle of
  Glacial Acetic Acid Showing Warnings

Another Example

The Institute for Safe Medication Practices has also reported patient injuries associated with undiluted glacial acetic acid being mistakenly dispensed for a medical purpose. For example, wound irrigations were ordered for a paraplegic with bilateral greater trochanter wounds. The nurse called the Pharmacy and requested “acetic acid for irrigation.” The pharmacist dispensed glacial acetic acid, which was used for two days. As a result, the patient sustained burns of the irrigated wounds. The wounds never healed, and the patient ultimately underwent disarticulation of both hips.¹

As seen in the examples above, errors involving glacial acetic acid can cause serious patient harm. Since this chemical serves no medical purpose in its undiluted form, the most effective strategy to prevent error is to remove glacial acetic acid from your facility altogether, making it available only in diluted forms. Other strategies include:

• Determining and standardizing on only the acetic acid concentrations your facility requires for medical purposes.
• Purchasing commercially available, pre-mixed acetic acid solutions for medical purposes.¹
• Conferring with medical staff to determine the lowest acetic acid concentrations required to be medically effective.
• Determining to what extent table vinegar (5% acetic acid) could be used for medical purposes, rather than pharmacy compounding this concentration from glacial acetic acid.
• Outsourcing dilution of acetic acid to a trusted pharmacy service so that glacial acetic acid is no longer needed in house.³
• Requiring prescribers to:
• Specify the exact strength of acetic acid required
• Not use “glacial” in the order (such as, “dilute glacial acetic acid”)¹
• Educating all staff that glacial acetic acid is never used for medical purposes, and that glacial acetic acid is the most concentrated form of acetic acid.¹ The Material Safety Data Sheet and container label can be used to emphasize the dangers of this chemical.

• Diluting it immediately to standard concentrations and storing the diluted product for medical use.¹
• Placing the glacial acetic acid in a separate, locked area¹ away from the compounding area in pharmacy, so that it does not become confused with diluted acetic acid.
• Posting a written alert where glacial acetic acid is stored, indicating that it must be diluted for medical purposes.
• Placing a brightly colored label on the glacial acetic acid to differentiate it from other concentrations.¹
• Placing diluted acetic acid in visibly different containers than those used for glacial acetic acid.
• Requiring that orders for compounding glacial acetic acid be forwarded to pharmacy at least one business day before the product is to be used – to allow adequate time for compounding the solution.
• Prohibiting interruptions when compounding glacial acetic acid.

The facility that reported the occurrence to PA-PSRS conducted a root cause analysis and implemented several strategies to prevent a recurrence and/or mitigate harm from the error:

• Departments requesting acetic acid must use an order form and specify the concentration and purpose.
• Implementing in Pharmacy a double-check/observation process to confirm that glacial acetic acid is properly diluted.
• Reviewing the compounding log with Pharmacy staff and having it readily available as a reference when performing dilutions.
• Educating the pharmacist and staff concerning the dangers of glacial acetic acid and that it is not used for medical purposes in its concentrated form.
• Educating staff not to use acetic acid if it smells different/stronger than usual.
• Every department that uses acetic acid has baking soda available to neutralize the concentrated acetic acid, should exposure occur.

Bottom Line

Glacial acetic acid is just one of many dangerous chemicals that are used in healthcare facilities.

Many of the strategies mentioned above are applicable to reducing risks associated with any dangerous chemical. Facilities can begin by taking an inventory of dangerous chemicals in all departments and limiting the number and amount of dangerous chemicals kept in stock by replacing them with safer alternatives when possible. If dangerous chemicals must be used, they can be segregated and secured. A double-check process can be implemented to ensure appropriate use. Clear labeling of dangerous chemical containers (contents, dangers, appropriate use, first aid measures) and readily available chemical information sheets ensure that such chemicals are used properly and with appropriate caution. By implementing system changes, the facility can build in mechanisms to prevent a dangerous chemical from reaching the patient.

1. Institute for Safe Medication Practices. End the ice age – is glacial acetic acid really needed? ISMP Medication Safety Alert: 2005 May 5;10(9):1-2.
2. Mallinckrodt Baker, Inc. Material Safety Data Sheet. Acetic Acid Glacial [fact sheet]. MSDS Number A0326 [online]. 2005 May 6 [cited 2005 Dec 23]. Available from Internet: http://www.jtbaker.com/msds/englishhtml/a0326.htm.
3. Institute for Safe Medication Practices. Messages in our mailbox – in response to our May 5, 2005 article. End the ice age – is glacial acetic acid really needed? ISMP Medication Safety Alert: 2005 Jun 30;10(13):3.