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Ultrasonic Cleaners

 
  • Covering the ultrasonic.

    OSHA Section 9 - IX comments:
    "Although there has been concern about potential infectivity of aerosols generated by dental, medical and laboratory equipment, HBV has not been detected in such aerosols, and risk is posed primarily by large particles of 'spatter' that travel only short distance. (Tr 9/14/89,p.21)"
    "The term 'aerosolization'...has been replaced with 'generation of droplets.'" OSHA Section 9 XI
    "...There has been no documented cases in the literature...of HIV transmission via aerosols..."
    "...To the best of our knowledge...there have been no cases."
    "...Aerosols are not known to present a risk of transmission of blood borne pathogens...Therefore, use of respirators for protection against blood borne pathogens is not recommended.p.50
    "...The current opinion of experts is that, while aerosol transmission is a theoretical possibility, it does not contribute measurably to occupational transmission..."
    "...There are no known instances...nor are other instances known in which airborne particles containing bloodborne pathogens have presented a risk to health care workers."p.50
    "CDC/NIOSH...Aerosols are not known to present a risk of transmission of bloodborne pathogens in the healthcare environment.  There are no known instances...
    "aerosol" should not be used in the same context as splatters and splashes (Ex 20-1157)p.51

OSHA intends a distinction between "droplets" and "aerosols"
to make it clear that "droplets" "spatters" "splashes" (such as produced by power saws and drills) are  of concern, not  'aerosolization' (as produced by ultrasonics). As you read further notice the distinction.

"Splattering of blood onto skin or mucous membranes of the face and upper respiratory tract against large droplet splattering is needed. ...glasses, goggles, face shields, and surgical masks...as appropriate to the task being performed, can provide that protection. "OpCit p.51

Pseudo-scientists put some "marker-dye" in an ultrasonic and observed the "marker dye" was aerosolized and deposited on surfaces away from the ultrasonic.  They concluded that covering that ultrasonics was necessary to limit the spread for pathogens and protect the worker. Their experiment was faulty and their conclusions were false.

The emphasis by OSHA is to encourage the establishment of procedures that prevent the initial problem before focusing on protection.

"Paragraph (d)(2)(xi) requires that all procedures involving blood or other potentially infectious materials shall be performed in such a manner as to minimize splashing, spattering, and generation of droplets of these substances."

"The hierarchy of controls provision, paragraph (d)(2)(i), of this standard requires employers to implement engineering controls and work practices prior to relying on personal protective equipment for protecting employees against exposure" OSHA

Ultrasonic cleaners are used to dislodge fine particles
that other cleaning methods may not be able to reach or remove.  
Ultrasonics are not Washers.
It would be contrary to manufacturer's instructions or expectations to try and clean grossly dirty instruments. Items to be ultrasoniced must be pre-cleaned.

Whereas surface tension is broken and aerosolization occurs we can cover the ultrasonic though there is no reason to think it should be required.

Cavitation is the term used to describe the mechanical (physical)
vibration effect that occurs when high frequency sound waves are introduced into a solution.
The vibration causes minute vacuum- bubbles to form which
when they contact an object "implode." 
The disappearing vacuum is a micro-implosion causing the bubble to disappear pulling its surroundings in with tremendous force. 
Fine particles on objects are pulled into the space 
releasing them from the object and they become suspended in the liquid by the soap.

Plain water is a poor cavitator and requires a soap solution to work.

Cost-effective Alconox is the long preferred cleaner because it rinses clean without leaving a soapy residue.

Tip 1:  Maintain water level to within 1/2" of top rim of ultrasonics.

Tip 2: Always use a basket suspending the object 1/2" or more above the bottom. 
Never place anything directly on the bottom.

Tip 3: Ultrasonics do not sterilize or disinfect, they only remove fine particles from items being cleaned and the dirt is then suspend in the solution.  Items should be rinsed and dried before packaging for sterilization.

The Unimax System
for safe handling of contaminated instruments
for tattoo and piercing.

Used contaminated water from ultrasonics should be treated with 10% bleach and then poured into the sanitary sewer system down the toilet being careful to avoid splashing.

It is a violation of OSHA regulations to dispose of untreated contaminated liquids into the sewage system.