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Instrument Processing



Infection Control: Creating Your Policies and Procedures

CDC: Guide to Infection Prevention for Outpatient Podiatry Settings    

CDC: Indications for Sterilization, High-Level Disinfection, and Low-Level Disinfection

APMA: Disinfection and Sterilization Guideline Recommendations for Podiatric Physicians 

Research recommendations in your area. For example: Boston Public Health Commission states that nail salons "...must use either an autoclave or a dry heat sterilizer to sterilize multi-use tools before they can use them again on another client. Salons may not use or possess UV light boxes, also called UV sterilizers". These requirements are for both infection control and worker safety, as chemical exposure is hazardous to your health.

According to the CDC:

  Sterilization should be used on critical items (e.g. tools that penetrate tissue that has a blood supply).

  High-level disinfectants can be used on semi-critical items (e.g. tools that come into contact with non-intact skin).

  Low-level disinfectants can be used on non-critical patient-care surfaces (e.g. foot stools) and equipment (e.g. tuning fork). 

Following CDC recommendations, the American Podiatric Medical Association (APMA) guidelines (last updated March 2019) recommend:

  High-level disinfectants (at a minimum) should be used on tools for manual debridement (e.g. nippers and curettes).

  High-level disinfectants (at a minimum) should be used on tools for mechanical debridement (e.g. burrs).

  With mechanical debridement you must use dust extraction equipment.


The APMA further recommends that heat stable instruments that have the "potential to break intact skin during ordinary use" (e.g. nippers, burrs, and curettes) should not rely on liquid chemicals for sterilization. Regardless of the terminal reprocessing method, APMA states that all tools must be thoroughly cleaned, as inorganic and organic materials that remain on the surface of instruments will decrease the effectiveness of disinfection/sterilization. The CDC recommends this as well.

Canada has more clearly stated and stricter standards than the US for processing foot care instruments. See the Reprocessing Decision Chart from Ontario Agency for Health Protection and Promotion for all options for cleaning, disinfecting, and sterilizing (full document here). In Canada, foot care equipment is considered critical and requires sterilization.

What does this mean for practice? APMA refers to cleaning methods for manual (e.g. friction (rubbing/scrubbing with a brush) and fluidics (fluids under pressure)), as well as mechanical (e.g. ultrasonic cleaners or washer-disinfectors). The minimum required cleaning method would be using water and detergent with a brush and rinsing well and drying thoroughly before disinfection/sterilization. This may mean that you need multiple sets of tools so clients aren't exposed to improperly disinfected or sterilized tools. 

Not convinced? Read about these unfortunate cases in the US (back-up link).

Multiple Sets of Tools

"An adequate supply of clean and disinfected or sterilized patient-care instruments should be brought to (or be available at) the off-site facility so that items do not have to be reprocessed at the off-site location to maintain clinical workflow."

See "Reprocessing of Medical Devices with Off-Site Podiatry Care", page 31, of the full guide for more details.

Nippers and reusable burs need to be cleaned prior to disinfection/sterilization. This means you need multiple sets of tools.


To cut costs, just have your set of multiuse tools include a nipper and a mandrel. There are $100 nippers that work great. They don't have to be extra heavy duty. It's best to thin out nails before cutting them; it hurts the client less and puts less strain on your hands. Mandrels can be about $10, or less if on sale. Sanding bands can be found very affordably on Amazon. Then use single use orange sticks and emery boards. This will lead to faster processing times and fewer cycles in the autoclave or dry heat sterilizer.

Sterilization versus High-Level Disinfection

Sterilization and high-level disinfection both eliminate all microorganisms. The difference is that sterilization also eliminates bacterial spores, which aren't eliminated by high-level disinfection. Read more about the differences from the CDC.

What harmful bacteria make spores?

Bacillus anthracis - Anthrax

Clostridium botulinum - Wound botulism

Clostridium tetani - Tetanus

Clostridium perfringens - Gas gangrene

Clostridium difficile - C. diff

Dry Heat Sterilization

Dry heat sterilizers rely on time, temperature, airflow rate and air distribution, and load configuration. They typically use convection to dehydrate and destroy microorganisms. There are two forms of convection: static air and forced air. Static air convection is preferable for lightweight items that could blow around. Because there is no fan, the chamber temperature is less uniform. Forced air convection uses a fan to keep temperature consistent in the chamber, which is ideal for destroying all microorganisms and spores.


Because dehydration is the mode of action, water content affects efficacy. The more microorganisms and spores there are on the surface of the tools, the longer it takes to destroy them all. This is why you must thoroughly clean your tools before beginning a cycle, ideally with manual cleaning and ultrasonic cleaning. It is also why dry heat sterilization takes 60 to 150 minutes depending on the chosen temperature. Tools exposed to dry heat must also cool down. There are dry heat sterilizers with cool down modes that have vents and HEPA filters to speed up the cool down process. The simplest method is to keep the chamber door closed and let it cool down on it's own, which does take hours. That's why it's helpful to have a chamber large enough to hold all of your tools and let it cool down overnight. Unless you prepackage your tools, you don't want them to sit around on a counter, cooling down, and collecting microorganisms. 


Dry heat sterilization requires mechanical, chemical, and biological indicators and a sustained temperature over a period of time (e.g. I process my tools at 170 degrees Celsius for 2 hours, which is more time than the minimum time required). See below if you are interested in setting up for dry heat sterilization with an FDA registered dry heat sterilizer. You can read more about dry heat sterilizers here.

Steam Sterilization

Read about Autoclaves from the CDC website


Liquid Chemical Disinfection

According to the FDA, "The Environmental Protection Agency (EPA) no longer regulates such sterilants/high level disinfectants. The FDA now has sole regulatory jurisdiction over liquid chemical sterilants/high level disinfectants intended for use to process reusable heat sensitive critical and semicritical medical devices." A Memorandum of Understanding from 1994 is available on the EPA website. When choosing a high level disinfectant, follow FDA recommendations, but also consider the EPA, which protects the environment and the CDC, which controls and prevents diseases. The FDA ensures that products are safe for the public. Each agency is important. Intermediate and low level disinfectants are still regulated by the EPA. When choosing a "hospital grade disinfectant", i.e. an intermediate or low level disinfectant, choose one that is registered with the EPA.


Liquid chemical sterilants and disinfectants are subject to FDA Class II Special Controls and as such, are subject to FDA premarket notification requirements. One of the parameters includes "intended use". If using high level disinfection, you would need to pick a product from the FDA list: FDA-Cleared Sterilants and High Level Disinfectants with General Claims for Processing Reusable Medical and Dental Devices. Additionally, you would need to find a product that claims the correct "intended use", i.e. find one that claims it is for use on metal instruments or surgical tools.

According to the CDC and the FDA, liquid chemicals should only be for heat-sensitive critical devices that are incompatible with other sterilization methods. The EPA concurs, also suggesting to decrease the use of Glutaraldehyde - a recommendation dating back 20 years. 

Responsible use of high level disinfection/sterilization agents includes:


-Cleaning instruments thoroughly before disinfection.


-Leaving the instruments submerged for the necessary amount of time.


-Rinsing the instruments off with water and drying before contact with the client.

-Testing the solution before each disinfection, keeping a log, and stopping use as of the expiration date.

-Using a deactivator before disposal (if applicable) under the direction of local, State, and Federal authorities.

-Disposing of the solution per local, State, and Federal authorities (probably not down the drain).

Always follow the Safety Data Sheet (SDS) for proper use and handling of the chemical. Please note that SDS information changes and you must have the most recent SDS as supplied by the manufacturer or the manufacturer's website. Very often liquid chemical disinfectant disposal instructions (found in section 13) will direct you to follow Federal, State, and local regulations. I was informed that any liquid chemical disposal had to be removed by a professional disposal company and I would need a hazardous waste generator ID. Long story short, for me, it's too expensive to discard properly. This does not mean pour it down the drain! Keep searching for an environmentally friendly way to sterilize/disinfect your tools and get verification from Federal, State, and local authorities for how to discard liquid chemicals. Refer to the SDS for disposal of the container, as some indicate that they cannot be recycled.

A "Down-the-Drain Model" is used for "estimating potential exposure of humans and aquatic organisms to chemical substances that are used in products that enter domestic/municipal WWTP [wastewater treatment plants]". A Down-the-Drain Assessment has been conducted for glutaraldehyde, because of the "relatively long" half-life in water, as described by the EPA. It has been found to be an "acute risk to endangered freshwater invertebrates and aquatic plants...". Other chemicals are difficult to break down as well and some need a deactivator added to them before discarding. Always check in with your local and State authorities. Official Federal regulations are difficult to find, but Federal recommendations are readily available.


According to the EPA, "toilets aren't trash" and pesticides, which include antimicrobials that kill bacteria, viruses, and fungi, should not be poured down the drain. Healthy bacteria in wastewater treatment plants (WWTPs), septic tanks, and drain fields breakdown organic matter; these bacteria can be destroyed by antimicrobials leading to harmful run-off from WWTPs and negatively impacted septic systems. The EPA states: "Harmful chemicals put down your drain can also be discharged into the groundwater and can impact drinking water supplies and the environment." The EPA continues to convey the message: DO NOT POUR CHEMICALS DOWN THE DRAIN.

Ask yourself: what are the priorities for people who pour chemicals down the drain? Is it because they have verified documentation from local, State, and Federal authorities that it is safe to do so? Or is it because it is too expensive to dispose of them properly?

Know Your Chemicals

Before using a chemical based on a colleague's or instructor's recommendation, research all of your options and understand the health and environmental hazards that may come with each chemical. FDA cleared and registered products are the safest choice. Verify your method of disposal with Federal, State, and local authorities.

FDA-Cleared Sterilants and High Level Disinfectants with General Claims for Processing Reusable Medical and Dental Devices. This content is current as of 09/25/2019; however, manufacturers may have made changes. 

Search for information on chemicals on the EPA website.

Common Sterilants and High Level Disinfectants include:

Glutaraldehyde/Glutaral: the EPA advises the use of OPA over Glutaraldehyde. The CDC, EPA, and OSHA state that Glutaraldehyde is for heat sensitive instruments.


MetriCide 28 - FDA registered and FDA cleared - use includes for stainless steel instruments - 90 minutes at 25+ degrees C.


US EPA - Pesticides - Reregistration Eligibility Decision (RED) for Glutaraldehyde Reregistration Eligibility Decision (RED) for Glutaraldehyde


CDC Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) Glutaraldehyde

OSHA Best Practices for the Safe Use of Glutaraldehyde in Health Care (2006) 


Ortho-phthalaldehyde (OPA): "Intended use" limited and does not include "metal" or "surgical instruments".


MetriCide OPA Plus - FDA registered but not FDA cleared - high level disinfectant for reprocessing heat sensitive semi-critical medical devices when sterilization is not suitable - 12 minutes at 20 °C (68 °F)

Cidex OPA Solution - FDA registered and FDA cleared - high-level disinfectant for reprocessing reusable heat-sensitive semi-critical medical devices such as endoscopic, respiratory therapy, and anesthesia equipment - 12 minutes at 20 °C (68 °F)


Evaluation of Ortho-phthalaldehyde in Eight Healthcare Facilities


CDC Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) OPA

Directions for use: CIDEX® OPA High Level Disinfecting Solution TECHNICAL INFORMATION

Stainless steel was included in the materials compatibility testing, however it only instructs use on heat-sensitive devices.



Isopropanol/Isopropyl Alcohol: ignitable and cannot be poured down the drain. According to the CDC, the "FDA has not cleared any liquid chemical sterilant or high-level disinfectant with alcohol as the main active ingredient.


Barbicide - not FDA registered and not FDA cleared - LOW LEVEL DISINFECTANT - Isopropyl alcohol is the main inactive ingredient. The active ingredient is Alkyl (50% C14, 40% C12, 10% C16) dimethyl benzyl ammonium chloride with sodium nitrate added to inhibit rust. "Use to disinfect all hard, non-porous items and surfaces such as glass, metal or plastic." - 10 minutes (or more as required by local authorities)


Alkyl (50% C14, 40% C12, 10% C16) dimethyl benzyl ammonium chloride was included by the 1985 EPA's Guidance for the Registration of Manufacturing-Use and Certain End-Use Pesticide Products for use on surgical equipment (p. 75). The chemical is currently EPA registered. The same document informs that this compound type does not destroy bacterial spores, hepatitis, hydrophilic viruses, or Mycobacterium tuberculosis. This means it is a low level disinfectant, which can only be used for surfaces that are in contact with intact skin. 1985 is a long time ago, standards change for what is considered safe disinfection.


Barbicide, as well as it's active ingredient, is not on the FDA approved list of liquid chemical sterilants/disinfectants, because it is not a high-level disinfectant. Barbicide is EPA registered with an approved label amendment in 2021, but the EPA does not regulate high level disinfectants - the FDA does. Alkyl Dimethyl Benzyl Ammonium Chloride (ADBAC) is a Quaternary Ammonium Compound (QAC). QACs are low level disinfectants and cannot be substituted for high level disinfectants. 


On the Label: "Pesticide wastes are acutely hazardous. Improper disposal of excess pesticide, spray mixture, or rinse water is a violation of Federal Law. Wastes resulting from the use of this product may be disposed of on site or at an approved waste disposal facility."

U.S. EPA. Provisional Peer-Reviewed Toxicity Values for Isopropanol (Isobutyl Alcohol). U.S. Environmental Protection Agency, Washington, DC, EPA/690/R-14/009F, 2014.


Hydrogen Peroxide: "Intended use" limited and does not include "metal" or "surgical instruments". Verify your instruments' compatibility - will likely damage carbide burs, may cause rust.

Example: Resert™ XL HLD / Resert™ HLD -  FDA cleared / FDA registered - high level disinfection - 8 min at 20ºC - Biodegradable

FDA 510(k) Summary For ResertTM XL HLD High Level Disinfectant


CDC Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) Hydrogen Peroxide


Bleach: corrosive to metal.


"Hospital Grade Disinfectants" are defined as low level or intermediate disinfectants, i.e. for use on surfaces that only come into contact with intact skin. In ideal situations, no skin is cut during nail care, but it happens quite frequently in rushed situations. If there is any risk of cutting live tissue or coming into contact with non-intact skin, you must use a high level disinfectant and ideally sterilize.

Low and Intermediate Level Disinfectants: do not substitute for use as a high level disinfectant.



Dry Heat Sterilization Set Up

Infection Control
Multiple Sets of Tools
Disinfection vs Sterilization
Dry Heat Services
Liquid Chemical Disinfection
Know Your Chemials
Dry Heat Items
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