Many Blue Water Task Force volunteers have expressed concerns over the amount of plastic disposables used and discarded while collecting and analyzing water samples. Single use plastics are used to maintain a sterile environment and to avoid contamination of water samples. As our chapter water testing programs have become more established, accrue more experience and resources, and form valuable partnerships with other laboratories, many have chosen to cut back on the number of plastic disposables by sterilizing glassware in an autoclave instead. Although glassware is initially more expensive than plastic supplies, it is well worth the investment if your chapter has an established testing program, enough funds and space to set-up an autoclave (or one you can borrow). Read more about reducing your water testing program’s plastic footprint and making the transition to re-usable glassware below.
An autoclave is used to sterilize equipment and supplies by subjecting them to high pressure steam at 121 °C or more. Autoclaves are widely used in microbiology, tattooing, body piercing, medicine and dentistry. Autoclaves can range anywhere from the size of a large refrigerator to a big cooking pot.
There are two types of small autoclaves available (about the size of a microwave oven). Steam autoclaves work like a pressure cooker, they are inexpensive (approximately $500) but they can be a bit dangerous and time intensive to run. They shouldn’t by used by children because of the risk of getting burned by the steam, and someone needs to constantly monitor the autoclave for the 1-2 hours it takes to run to make sure the heat levels stay in the appropriate temperature range. The other option is a dry autoclave, which you are able to set up and leave unattended. When you need the glassware next it will be sterile and dry. These are more expensive; roughly $2,500 - $3,000 for a small model that can accommodate the glassware used by our labs. Dry autoclaves, however, are much safer to use and are therefore recommended for BWTF labs.
With a little bit of detective work, however, your chapter might be able to find a good dry autoclave that you can borrow without having to buy one yourselves. Contact any university, state or federal laboratories that might be in your area to see if they have any old models they could donate to your program. These labs often upgrade their equipment and are left with older models stockpiled. Sometimes high school science teachers have autoclaves packed away in their closets collecting dust and don’t even know they are there. So check around with science teacher friends, environmental and microbiology labs, even tattoo parlors, you never know where you might find one. Local labs may also be willing to autoclave your glassware if you set up a regular schedule with them.
2) Glassware
You can purchase glass collection and mixing vessels, pipettes and test tubes (if using the multiple test-tube method) to replace their plastic disposable counterparts. There are autoclavable plastic vessels available that can be reused, but our labs have found that glassware stands up better over time.
Some products that we recommend are 125 ml graduated sample bottles, which can be used to both collect samples and mix with reagant and glass pipettes.
3) Accessories
You will need some tin foil and autoclave indicator tape to verify that your glass ware is sterile coming out of the autoclave. You should also store your sterile equipment by sealing the autoclave tape along tin foil wrapped glassware or plastic. This seal will keep fingers, dust, and other possible contaminants away from sterile products. Indicator tape varies with the type of autoclave you are using, some different options are available here.
You may also want to purchase an autoclave bin to hold your glass pipettes in the autoclave during sterilization.
Please contact Mara Dias at mdias@surfrider.org with any questions about autoclaves and glassware or to purchase any of the above items. Many of these items can be purchased by Surfrider for less than the prices posted on the internet.