King County Medical Industry Round Table (MIRT)

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Chemical Management
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Waste Management

Medical Industry
Waste Prevention Round Table

Seminar #2
Managing Chemicals
From Hospitals and Biomedical Labs

Center for Urban Horticulture April 6, 2000

Meeting Facilitators:
Dave Stitzhal, Full Circle Environmental
Ron Claus, University of Washington
Dave Waddell, King County Hazardous Waste Mgmt Program

Focused on 3 waste streams
-Alcohols (a solvent but regulated and used differently than other solvents in biomedical settings)
-(and start on stains)

Ron Claus (UW): Use 3000 gal./year. Much from histology/pathology. It is managed at the UW's waste facility so recycling includes costs of transportation from various facilities.
-Distill w/ 20 liter solvent recycler, and repackage. Some into one-gallon bottles which go to UW stores. Some to five-gallon carboys delivered directly to user.
-If disposed, per gal. - cost $1.50 disposal plus $1.50 for transport and labor
-If recycled, per gal. - $1.50 for transport and labor plus $1.50 distilling cost plus cost of bottle ($10 each, only some come back from labs for recycling) total $6.00 per gal.
-Cost to purchase new xylene $20.00 per gal. (Puget Sound Institute of Pathology (PSIP) purchases xylene for $34/ 4 gal.)
-UW bulk packaging even cheaper because it eliminates expensive bottle

(PSIP): uses CBG Biotech Recycling unit ("still") for ethanol and xylene.
-2.5 gal. capacity
-ethanol process takes 3 - 3.5 hrs., do everyday
-xylene takes 2 hrs., do weekly
-virtually no set up time for a run
-xylene from cytology and histology are recycled together
-machine has lots of safeguards
-$15,000 - $17,000 cost and 2 year payback

(St. Joseph's, Bellingham): uses VR Instruments recycling unit for toluene and Clearite, a xylene substitute with lower human toxicity than xylene or toluene
-4 gal. capacity · toluene process takes 3.5 - 4 hrs
-Clearite takes 2 hrs.
-set up time about 0.5 hours due partly to location of machine and location of stored used solvent
-plan to recycle alcohols too but haven't gotten an acceptable product yet, still working on it
-machine has safeguards and alarms
-$17,000 cost, if doing alcohols too would have a 14 month payback

NOTE these two machines are not considered "stills" by fire departments based on several factors, including that they cannot increase the strength of the alcohol/solvent put into the machine (if you put 80% in you can't get it to produce 90%).

Denise Bender (Immunex): using CBG unit but couldn't get to high enough percent alcohol for their needs with it, so amended their liquor license and now use 190 proof ethanol.

Lisa (VA Hospital): they use a filtering system, not a still, keep filtering until product is too dilute to use again. Likes the system, but heard the manufacturing company was going out of business (see below)
-One gallon alcohol takes about one hour
- Filter cartridge life depends on concentrations of stains removed, etc.

Rex Johnson (Creative Waste Solutions): Yes Naiad Technologies went out of business but same process now available from his company. Gravity system, can be used to filter alcohol, xylene, and now testing a cartridge for formalin.

REGULATIONS: Dave Waddell (King County): guidelines for what can go down the drain differs from place to place based in part on where the sewage treatment plant's discharge goes. Example: Seattle discharges to Puget Sound, metals limits are in the 3-5 ppm range. Snoqualmie discharges to the Snoqualmie River, copper limit is 3 ppb (billion!). Know where your sewage is going and research the limits you are required to meet.

If something designates as a dangerous waste in WA it can't go down the drain to the King County sewer system unless specifically allowed by the local sewer agency. So F-listed solvents if at concentrations of >10% and/or with flash point below 140 degree F can't go down the drain.

Contact Dave Waddell (206) 263-3069 or if you didn't get a copy of the Laboratory Waste Management Guide , contains tables noting King County sewer and solid waste guidelines.

NOTE: alcohols have a Federal exemption from being regulated as an ignitable liquid IF their concentration is less than 24%. Federal exemption says <24% isn't ignitable waste, therefore it isn't hazardous waste so it's OK. BUT in WA some alcohols designate for toxicity at 10% to 24% concentrations so in WA they are hazardous waste, they may not be in other states. Ethanol is ignitable liquid if >24%. If below 24%, not regulated as hazardous waste.

NOTE: Dilution as a treatment method for hazardous waste is illegal. Most medical solvent and alcohol waste is >10-24% so legal treatment methods (filtering, distillation) that have a 2-3 year payback period may be very good investments.

SOLVENT ALTERNATIVES: (Children's Hospital): Unfortunately, they were unable to attend, but we're aware they're using a xylene substitute which has a much higher flash point than xylene, and have been recycling it on site for several years successfully.

What's being used for disinfection? Immunex switched to, and is trying to now get away from, aerosolized isopropanol, 70%. Found mold spores in a pump-spray bottle once so switched to aerosols. They've had problems with it being used inappropriately in hoods and staff get a face-full sometimes from excessive over-spray.

Does anybody have an automated stain line plumbed directly to sewer? Not in this group.

(Alan Jones, Lance Environmental Services). Is there a problem with labs trying substitutes in terms of certification of methods, and perhaps payments by insurers etc.?
(Lisa, VA Hospital) It's OK to substitute but different solvents/stains lead to different look on the slides so either need to retrain the whole staff or stick with old method, usually cheaper to stick with the old way, not to retrain..
(Participant, NW Hospital) Not aware of any restrictions against new methods.

What about d-limonene? Can nauseate some people. Has high fish toxicity and is ignitable so does designate as a hazardous waste. Many people also have strong allergic reaction. It's a good defatter so gets in blood stream quickly, bad reaction to it shows up quickly. Just because it is a 'natural' product doesn't make it a safe product.

What's the difference between a still and a recycler? Some difference in the heat used and the process, a still can remove water to some extent and give you a higher percentage alcohol. A recycler only gives back the same strength that was put in.
NOTE: Fire departments see red flags when they hear "still" and so even if the difference is a semantic/legal one it may be best to use "recycler" when discussing with fire department.

NOTE: Get the local fire department involved BEFORE you purchase a $17,000 piece of equipment. Implementation of the fire code differs from town to town, occupancy ratings means in some places its OK to install, others not. You generally need to have a fire department permit to operate one. Get the permit first so you don't have an expensive paper weight.

Watch for contamination with other solvents - boiling points may be too similar to separate for adequate purity.

Vacuum assist can lower boiling temperature needed, fire departments like that.

Alan Jones (Lance Environmental): neither type can get all the water out of dilute alcohols. 50 ml water with 50 ml alcohol will not yield 100 ml of liquid. They form an azeotrope, strong Hydrogen bonds form that distillation can't break. 96-97% pure is the best you can get from a distiller unless you've started with a higher purity.

Rex (Creative Waste) can supply the name of a person in Florida who has a lot of experience with many types of these machines and is willing to discuss it.

Dave Waddell: Lab guide pages 8-12. Once you use a product to the point you can't reuse it, it becomes a waste. If it is hazardous at that point it is a hazardous waste, and according to the regulations, it must be counted toward assessing your generator status. You can then treat and/or recycle it on-site to make it non-hazardous or reusable. If you do that and you are an SQG you don't have to report the amount that you treated or recycled but you still need to track it and keep a record of it. Keep a log.

You must · track it · handle it safely · dispose of it properly

Log includes: · What it is · Where it's from - what process · How much put in · When put in · Who put it in

Logs need to be kept for formalin neutralization and filtration. Solvent and alcohol filtration and recycling. Also acid neutralization

Regulatory technicality: You count everything that goes in to treatment. Then you must also count the sludge or still bottoms that are left over if they designate as hazardous waste. Yes, it is double counting that portion. Both of these amounts count toward your annual generator status. Only the still bottoms that are sent off-site need to be included in annual reporting for Pollution Prevention Planning. NOTE: This was a unclear in the discussion. We can discuss this again at session #4, or you could contact Ecology or Dave Waddell for clarification.


Ron Claus (UW): he has a sheet available with details on treatment methods and cost recovery. This is a significant part of the UW's waste stream. Tried distillation but had problems with how long it took to do and with the smells it generated.

Tried several different chemical treatment methods for neutralization. If you do any of this remember that OSHA/WISHA exposure guidelines need to be met.

Have been using Neutralex successfully. It is · quick · effective · reasonably inexpensive · there is documentation data available about the process that led to approval for discharge to the treatment plant · has a good dipstick test method to see when treatment is complete · works on gluteraldehyde too

In King County discharge limit is 0.1% since that is the point at which it designates as a hazardous waste. Neutralex instructions are for treatment to 0% so UW uses less than instructions since trace amounts OK for discharge. Still need to monitor for exposure, but haven't found any, no PPE needed by staff doing the procedure.

Treatment costs about $1.50 /gal. Which is much less than disposal would cost.

Some labs are treating their own by pouring into pre-loaded carboys.

Warning: don't use it on 37% formaldehyde, generates heat & fumes

Another product Formalex leaves a solid residue that needs to be filtered out, makes it less convenient and more labor intensive

Annatex is an oxidation process, better for small quantities of formalin

Deformalizer is a very smelly process but effective for formalin deactivation.

See Lab Guide page 15 for formaldehyde guidance

Glutaraldehyde disinfectants in concentrations of no more than 4% can go down the drain in King County, testing shows the King County treatment plants can treat those quantities and there is no danger to workers in the process

In King County you must determine concentrations at the point of disposal (the sink) to determine if it OK for sewer disposal, some jurisdictions measure at other places.

NEW PROCESS: formalin recycling. Dynacare testing system from Creative Waste Solutions. If it continues to work well, they estimate an annual saving of over $16,000 by filtering and reusing formalin rather than disposing or treating it and buying new. Pre-filter tissues and can use it for formalin from both processors and tissue.

Alan Jones: Another source of formaldehyde is kidney dialysis centers, typically using stronger formaldehyde, not formalin and typically plumbed directly to sewer. Substitute products are corrosive and may or may not be worse on the system.

Creative Waste filter cartridges are reusable - at least the alcohol ones. (DW) but remember to check the flushing wash water when complete - does it designate?


Please fill out survey and fax back. Add any stain processes you use. We will try to get disposal procedures for them by the September 7 seminar.

Many lab stain processes are done over the sink and rinsed right down. How do you deal with that? (DW) Remember that the rinsing may be part of the process and so if the whole batch including the rinse water is collected and tested it may not designate. If so that's fine.

Are there good substitutes for picric acid?? No answers to this question yet. Perhaps for the next seminar.

Next chemical session will include discussion of janitorial supplies, some are very dangerous. Also remember that maintenance staff working in the labs have little knowledge of materials in use, they may be injured when changing traps in sinks etc. Be aware of their safety too.

Also next: disinfectants, mercury, stains part 2, expired chemicals and prescriptions

Which drugs designate as hazardous waste??

British Columbia. has a trade association of pharmaceutical companies that developed a separate entity to buy back expired medicines. Costs are built into purchase price of drugs. Some US companies will buy back their own medicines for company credit towards new purchases.

What are people doing about spill clean up??

Committee is looking for ideas that they , and local government can help with that will produce measurable change based on what is learned in these seminars. Let us know about your ideas.
-Cooperative to buy a recycler? Business opportunity to be a mobile recycler?
- Need your managers to talk to managers who have approved alternate technologies and are reaping monetary benefits? We can facilitate these types of discussions. Sometimes peer to peer communications are the most valuable.
-Can you document changes you have made? Costs? Savings? Willing to share that information with this group?
-Do you want recognition from the public for doing the right thing? Local governments have programs to do that for you. Call us.


The Portable Rechargable Battery Organization sells a 5 gallon bucket with prepaid UPS sticker for $30. Holds 40 pound of Nicad batteries. That's all you need to spend. Get shipped to American Nickel and they recycle the nickel, and send the cadmium for recycling. Radio Shack and Ace Hardware are participating vendors can take batteries from home there to recycle.

Specialty chemistry and toxicology labs end up with "soups" of mixed solvents. Then as part of the process they evaporate the solvent to get the residues. Is that OK? Is there a process for capturing the evaporated solvents? (Dave W. and Immunex) Yes it's OK as long as there is a coil condenser that is designed to capture vapors in that type of process.