One of the safest forms of iodine disposal is to dilute it with water. Next, place the diluted solution in a sealed, labeled container and that container into the garbage.
Iodine can be harmful to fish, although in some specific cases, sink drain disposal may be the right option.
Unless you are undergoing radioactive iodine therapy and are otherwise instructed, always wear protective eyewear and gloves when handling iodine and its related chemical compounds.
Iodine can irritate the skin and eyes. Do not eat or drink when working with iodine.
Wear protective clothing, and tie long hair away from your face. Keep children under 12 away from iodine experiments.
Official MSDS Guidelines
As stated above, the official Material Safety Data Sheet (MSDS) for iodine states the disposal recommendation as follows:
“If Iodine is spilled, take the following steps:
- Evacuate personnel and secure and control entrance to the area.
- Eliminate all ignition sources [such as excessive heat, open flames, or even static electricity].
- Moisten spilled material first or use a HEPA-filter vacuum for clean-up and place into sealed containers for disposal.
- Ventilate and wash area after clean-up is complete.
- DO NOT wash into the sewer.
- It may be necessary to contain and dispose of iodine as a HAZARDOUS WASTE. Contact your state Department of Environmental Protection (DEP) or your regional office of the federal Environment Protection Agency (EPA) for specific recommendations.”
A HEPA (high-efficiency particulate air)-filter vacuum is a particular type of vacuum that traps allergens and particles, so they are kept out of the air we breathe.
Additionally, the reason the MSDS recommends moistening spilled iodine before clean-up is that pure iodine is soluble in water.
Please note that water solubility is not safe for all chemicals. It is not advisable to moisten or dilute unknown substances.
Do not dilute any other chemical compounds that include iodine without further research. Just because a compound contains iodine does not mean it is safe to follow the outlined procedure for pure iodine.
Other types of iodine that you should not mix with water are outlined throughout this article.
Disposal of Iodine Monochloride
Iodine monochloride is a different chemical compound than iodine. Iodine monochloride creates hazardous fumes when it comes in contact with water.
For this reason, handle this compound slightly differently than the above directions.
In this situation, as with above, your local waste management company should be consulted, as well as your lab’s safety and disposal protocols, if applicable.
Make sure the area is ventilated when using and disposing of iodine monochloride.
Put the solution into a labeled, airtight plastic container. The container must be plastic because iodine monochloride will react with other materials, such as metal.
To avoid creating toxic gases, do not moisten with water and do not pour the solution into the sink. Iodine monochloride is harmful to fish and wildlife, and therefore should not be drained into the sewer system for any reason.
If you spill iodine monochloride, use an absorbent material such as vermiculite, clay, or sand to clean it up. Again, do not use water when dealing with iodine monochloride.
Other Recommendations for Disposal
This section will go into a few more recommended ways to dispose of or deal with iodine in ways that may apply to your specific situation.
Working in a Lab Setting
If you are reading this article because you are using iodine as a chemist in a laboratory setting, this video by Flinn Scientific will be of interest to you.
The video discusses the concept of reducing.
According to Irene Cesa, Director of Technical Services at Flinn Scientific, Inc., because iodine has oxidizing properties, you can use a reducing agent such as sodium thiosulfate to neutralize the hazardous effect.
This process essentially cancels out the waste characteristic of a chemical, in this case, oxidation.
Waste characteristics are broken down into ignitability, corrosivity, reactivity, and toxicity. Oxidation falls under corrosivity.
The Environmental Protection Agency has a mandate about reducing, recycling, and reusing materials. The EPA encourages and allows neutralization because it minimizes excess waste.
The EPA also has an excellent resource for state-by-state regulations regarding this type of reduction disposal, titled “Little Known But Allowable Ways to Deal with Hazardous Waste.”
Flinn Scientific outlines the EPA’s resource paper here.
It is important to consult this, as well as the federal EPA website as a whole, to make sure you are within your state’s guidelines for the disposal of iodine, as well as any other chemicals with which you may be working.
Science Experiments for Young Adults
If you are working with children or young adults, MEL Science has a fun, informative experiment regarding the elimination of iodine.
Similar to Cesa’s explanation, the Disappearing Iodine experiment states that “disodium sulfate, a reducing agent, removes iodine stains.”
Like sodium thiosulfate, disodium sulfate reduces the oxidizing characteristic of iodine.
MEL Science recommends “dispose of solid waste together with household garbage. Pour solutions down the sink. Wash with an excess of water.”
Please note the solutions that you can pour down the sink should be neutralized by the experiment before disposing of in this way.
According to the Wireless Information System for Emergency Responders (WISER)
The most favorable course of action [to dispose of iodine] is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination
Unused iodine can be recycled or returned to the manufacturer. Be sure to recycle iodine only for approved uses.
WISER requires consideration of iodine’s impact on the environment. These factors include the potential mixing with soil or water, effects on plant and animal life, and impact on aquatic life.
To neutralize, mix iodine with reducing agents such as hypo- or bisulfites or ferrous salt solutions.
WISER’s mandate explains that iodine can be processed out of waste streams by recycling. Recovering iodine is a necessary process to consider when thinking about disposal as a whole.
As discussed prior, iodine can be neutralized, which reduces its oxidizing properties and makes it safer to handle.
Recycling this chemical compound minimizes the need for outright disposal, outlined below.
On a larger scale, iodine can be recycled.
According to A. Echeverria (Product Manager Iodine & Lithium, SQM), “Around 6 thousand metric tons of iodine are being recycled annually and sold back to the merchant market as fresh products.”
Japan, Europe, India, and America are major iodine producers that recover large amounts of iodine each year.
Many iodine-producing companies have turned to recovering and recycling iodine from natural water sources such as lakes, rivers, and streams.
If you work with iodine regularly, it may be helpful to ask your local waste management company if they have external contacts that reuse iodine where you can take your waste directly.
These may be nutrition companies, high school science departments, or university science departments. If you know the name of your local schools, it may be worth contacting them directly.
You can read more about iodine and related recycling processes here.
Disposal in the Case of Radioactive Iodine Treatment
Trigger Warning: The following section mentions death-causing illnesses and bodily functions.
In other instances, you may be wondering about the safe cleaning practices necessary after undergoing radioactive iodine treatment for cancer or thyroid problems.
In this case, it is essential to follow specific guidelines, and always consult your doctor.
The precautionary period usually needs to last a week following each treatment to keep your family and pets safe.
According to the Society of Nuclear Medicine & Molecular Imaging (SNMMI), drinking lots of water will help flush the radioactive iodine safely from your system.
Radioactive material is leaving your body, so it is crucial to make sure all of it is expelled from your household.
It is essential to dispose of used tissues and spit – from brushing your teeth, for example – in the toilet, and flush said toilet twice.
Additionally, flush the toilet twice after using the bathroom. SNMMI recommends cleaning the toilet after each use.
Showering daily, washing your clothing separately from your loved ones’ clothing, and washing your dishes away from theirs are all vital measures to take.
As you will notice, the recommendations set forth here contradict the official MSDS regarding sewer disposal.
This contradiction is due to the safety of your immediate loved ones, which should be a priority in the unfortunate event of a life-threatening illness.
Studies have shown that iodine-129 can be mixed into concrete for more durable disposal. This method is debated against oceanic disposal.
Conclusion and Best Practices
There are varying forms of advice when it comes to the disposal of iodine. To be safe, make sure you consult your local and state guidelines to determine which method is suitable for you.
The phone numbers for each state’s chemical regulatory department are listed in the EPA paper previously mentioned, “Little Known But Allowable Ways to Deal with Hazardous Waste,” as well as here.
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