Ortho-Phthalaldehyde (OPA): Small Sample Survey Summary
MedSun: Newsletter #97, July 2014

Survey Topic: Ortho-Phthalaldehyde (OPA) - Survey Final Report
Year Conducted: 2014


Reusable medical devices are devices that health care providers can reprocess and reuse to diagnose and treat multiple patients, for example, surgical forceps, endoscopes and stethoscopes. Reusable devices can be grouped into one of three categories according to the degree of risk of infection associated with the use of the device: critical (highest risk), semi-critical, and non-critical devices (lowest risk) . Semi-critical devices are those that contact intact mucous membranes or non-intact skin, such as endoscopes. Semi-critical devices are designed and labeled for multiple uses and are reprocessed by thorough cleaning and high-level disinfection or, if feasible, by sterilization. Ortho-phthalaldehyde (OPA) is one such high-level disinfectant.

The FDA conducted a small sample survey with clinicians and other health care providers to learn about users’ experiences with OPA in the hospital setting. The survey questions focused specifically on disinfecting and rinsing processes, training and instructions for use, and patient/staff reactions that may be related to the use of OPA. Information from the survey is intended to help FDA obtain a better understanding of users’ perspectives and any issues of concerns that may be present in the clinical environment.


A small sample of health care providers from hospitals that participate in FDA’s Medical Product Safety Network (MedSun) were queried to obtain detailed perspectives about the use of OPA. Respondents from nine different hospitals (located in the West, Northeast, Mid-Atlantic, and Southern regions of the U.S.) participated in the voluntary survey.

Six hospitals involved in the survey have over 500 beds and three hospitals have between 100-500 beds. All selected respondents have experience with OPA disinfectant in various clinical areas of the hospital.

The respondent sample included health care providers from Risk Management/Legal, Clinical Education, Nursing and Nurse Management, Quality Assurance, Industrial Hygiene, Infection and Prevention Control, Purchasing, Speech Pathology, Central Sterile Processing, and the Endoscopy Department.

Overview of Responses

Devices Disinfected with OPA

Nearly half the respondents use OPA to disinfect flexible and rigid endoscopes, and transvaginal probes. Other medical devices disinfected with OPA include the following:

• Transesophageal Echocardiogram (TEE) probes;
• Anal probes;
• Transducers;
• Wires;
• Dilators;
• Catheters;
• Stylettes;
• Rectal Biopsy Tools; and,
• Water Bottles (endoscope accessory)

Length of Time to Clean a Device after Procedure

Responses vary among respondents when asked how long after a procedure devices are cleaned with OPA. The length of time varied from immediately after the procedure to one hour after the procedure. This variation may be attributed to hospital procedures related to removing the device from the clinical area and transporting it to the cleaning/disinfection area. When a device has been used in the operating room (OR), staff responsible for cleaning the device will often have to wait until the procedure ends to receive it for cleaning. To try and minimize that exposure, they begin cleaning the device as soon as it’s received from the OR. All respondents say their facility has a standard operating procedure (SOP) for getting the device from the OR to the disinfection room.

Manual vs. Automatic Reprocessing

Medical device reprocessing is a set of validated processes used to render a medical device that has been previously used or contaminated, fit for a subsequent single use on another patient. These processes are designed to remove soil and contaminants by cleaning and to inactivate microorganisms by disinfection or sterilization. Typically, manual reprocessing is completed by hand by hospital staff and automatic reprocessing is done by an automated endoscope reprocessor (AER).

A combination of both manual and automatic reprocessing methods are used by the majority of respondents because of the variety of devices at each facility. Most manually clean devices such as transvaginal probes, catheters, and stylettes due to device heat sensitivity, lack of turnover volume, cost, and space requirements.

While utilizing manual cleaning methods for some devices, that same respondent may use automatic reprocessing for others, such as endoscopes. For the few respondents who only use automated reprocessing they work mainly with rigid and flexible endoscopes. Because scope turnover may be as high as 150 per day, automated reprocessing is faster and more accurate than manual cleaning.

Disinfecting and Rinsing Process

The OPA manual disinfection process is similar across the majority of respondents’ hospitals. Typically, prior to each use, the staff test the OPA effectiveness with test strips. The test strips measure the minimum effective concentration (MEC) to ensure the OPA will appropriately disinfect. The device is then checked to ensure it is free of leaks, tears, or other issues. Once those steps are complete the device is sprayed with an enzymatic cleaner such as Transeptic, wiped down and the surface is rinsed with fresh tap water. Then, the device is soaked in OPA for 12 minutes at a temperature of 68 degrees Fahrenheit or higher. Soaking is followed by three clean rinses with fresh water at one minute a piece. Usually all three soaking cylinders are changed out after each rinse. Then, depending on the device, it is hung to dry and excess moisture is removed by drying the device with a lint free towel. Once dry, the device is ready to be reused.

For automatic reprocessing, all cleaning is done by the AER. The AER rinses and soaks the devices based on parameters entered into the computer. Once the disinfecting cycle ends, alcohol is injected into the tubing and the machine flushes it out. Most AERs run at a temperature of 68 to 69 degrees Fahrenheit for 35 to 38 minutes. Some respondents also mention that they maintain records of all endoscopes that have been appropriately cleaned.

Staff Training

High-level disinfection training occurs during the orientation period for all new employees. All other staff typically receives training at least annually. Occasionally there are accompanying competency assessments as part of the annual or new staff training. Manufacturer representatives may conduct the trainings or hospital “super users” from various departments including Infection Prevention and Control and Central Sterile Processing may conduct the trainings.

Instructions for Use

All respondents think the OPA instructions for use are clear, easy to understand, and helpful to the user. The OPA instructions for use include information on manual and automated reprocessing. However, one respondent comments that even though the instructions for use are clear, they are too cumbersome and have too many steps. Another says they would like additional clarification on the practice of “topping off.” They say some OPA instructions for use don’t mention “topping off,” but believe the Association for the Advancement of Medical Instrumentation (AAMI) is currently updating its guidelines to discourage the practice. “Topping off” occurs when additional high-level liquid disinfectant is added to an AER or basin in an effort to extend the OPA reuse life. The practice of “topping off” may be discouraged because it does not extend the OPA reuse life, which should be determined by the first use/activation of the original solution.
Instructions for use are made available to staff in all areas where OPA is used. Staff can also access the instructions in the scope processing rooms, policy repositories, material data sheets, via the intranet, and the OPA containers themselves.

Personal Protective Equipment (PPE)

All respondents report that staff wear several pieces of personal protective equipment (PPE) when using OPA. These include:

• Protective eyewear;
• Masks and/or face shields;
• Gloves; and,
• Fluid resistant gowns.

To further minimize staff exposure to OPA, most respondents’ facilities utilize the following:

• Glutaraldehyde user stations (GUS);
• Room and/or other local exhaust ventilation; and,
• Negative air room pressure.

Patient/Staff Reactions to OPA and Other Medical Device Disinfectants

In general, respondents report few patient/staff reactions that may be related to OPA or other medical device disinfectants. One respondent said that if OPA is not properly rinsed off it may turn mucous membranes a darker color. Another says that several years ago they had 1 to 2 patients undergoing gastrointestinal procedures that exhibited sensitivity to OPA after repeated exposures. After this experience, devices for affected patients were disinfected with ethylene oxide (EtO) instead of OPA. However, the respondent is unaware of any other details involved in these occurrences. Another respondent says a staff member mentioned that they thought they had sensitivity to OPA, but it was never documented. Strong fumes are also mentioned as a staff complaint by one respondent, but it’s unclear if it was validated.

Few reactions to glutaraldehyde were reported. One respondent that previously used glutaraldehyde says their staff was instructed to wear glasses instead of contact lenses due to eye irritation. Another was aware of reports of staff skin rashes after working with glutaraldehyde. Another said their staff experienced respiratory issues that may have been from working with peracetic acids. However, they are all unaware of the specifics of those past issues.


Most respondents report that per hospital and manufacturer recommendations, OPA should not be used to clean devices for certain patients. These include patients who have undergone repeat cystoscopies. OPA is also contraindicated in patients with bladder tumors and bladder cancer.

Additional Information about OPA

Respondents provide the following opinions and additional information about OPA disinfectant:

• Stains staff clothing;
• OPA as a safer alternative to glutaraldehyde may be a misperception. The respondent reports that OPA may have a lower vapor pressure than other disinfectants, but the occupational exposure limit is much lower than, for example, glutaraldehyde.
• Manufacturers should limit the purchase of OPA to facilities that are knowledgeable about the instructions for use. The respondent has observed community practices using OPA inappropriately on metal steel instruments that could be steam sterilized. According to the respondent, it’s also likely that those community practices are not meeting the requirements for proper ventilation, PPE, storage, and rinsing. This can create an opportunity for injury to patients and employees. More education before a practice can order OPA can help them better understand the safety and health implications.


In general, respondents report few patient/staff reactions and sensitivities that may be related to repeated exposures of OPA and other medical device disinfectants like glutaraldehyde. Color change of mucous membranes, skin rash, strong fumes and eye irritation were some of the reactions/sensitivities respondents are aware of. The majority of respondents report using a combination of both manual and automated reprocessing methods at their facilities. Those who manually clean with OPA utilize similar processes. The most commonly cleaned devices with OPA include transvaginal probes, and rigid and flexible endoscopes. For those that use solely automated reprocessing, there are various types and manufacturer models of AERs used.

All respondents also utilize the same personal protective equipment while using OPA which includes gowns, gloves, eyewear, and masks. For the most part, respondents also think the instructions for use of OPA are clear, easy to understand, and helpful to the user. Instructions are kept in the areas OPA is used and can also be accessed online. Training is conducted during new staff orientation and then a minimum of annually by either hospital “super users” or the manufacturer’s representatives. Most also report that they are aware of OPA contraindications for certain patient populations.

Survey Limitations

Although the findings add to FDA’s knowledge of clinical experiences, and provide perspectives about the use of OPA, the small sample size of the survey limits the findings. In view of this limitation, the respondents’ perspectives may not represent the perspectives of all OPA users.

Therefore, these findings represent only one piece of information. No conclusions can be made about how OPA is used in the broader clinical environment based on this report alone. Instead, the report should be considered along with other information that may include adverse event reports, scientific publications, enforcement/compliance information, and other data sources that are part of FDA’s monitoring of device performance.

Surveying device users is one of many tools the FDA uses to evaluate the public health impact of potential problems associated with the use of medical devices. Typically, small sample surveys are used to collect qualitative information on post-market experiences of clinicians or facilities with medical device performance or use. The FDA selects survey respondents based on their experience with the topic or device, their availability, and their willingness to participate.

The FDA makes our scientific, medical, nursing, and engineering staff aware of the survey results as needed. If the FDA believes there is a significant risk of adverse events as noted from the survey, we will combine those results with data gained from other sources. The FDA will work with the manufacturers and health care provider organizations to make important information known to the clinical community. Additionally, the FDA continues to work with manufacturers to ensure the development, testing, and promulgation of methods for reducing the risk associated with these devices and to minimize the complications from adverse events that may occur in the course of normal usage. If the results of any survey raise serious concerns about the safety of these devices, the FDA may convene a group of clinical, scientific, and regulatory experts to discuss any necessary actions.

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