Does insect repellent expire?
It is usually a great surprise when you are sitting on the beach or trekking through a national park and you realize that the mosquitoes, sand flies, and ticks that you anticipated to be biting aren’t biting.
This may happen at any time. However, it is not very pleasant to spend twenty dollars or more on a full bottle of insect spray, only to discover that the product has lost some of its effectiveness when it comes time to use it.
Even while the majority of bug sprays and insect repellants do become ineffective over time, the good news is that this process takes a very long time. In addition, the “it may not work nearly as well after that date” warning that is printed on the bottle, if there is one, doesn’t actually signify much of anything else.
Which Insect Repellent Will Last the Longest?
The components of your bug spray that really work to repel insects are what are referred to as the “active ingredients,” and they are mostly responsible for determining how long the spray will remain effective
. It is possible that DEET, also known as N, N-diethyl-meta-toluamide, has an indefinitely long shelf life. DEET is the active component in many powerful insect repellents, particularly those that are used by hikers or campers in dense forests or jungles.
Because the quantity of DEET in insect repellent does not affect how well it works, but rather how long it continues to be effective, this is the reason behind this. The University of Michigan School of Medicine reports that an insect repellent containing 20 percent DEET will provide protection for around five hours, but a repellent containing 7 percent DEET would provide protection for just two or three hours.
It would seem that this is the reason why you should avoid purchasing sunscreen and bug spray combinations; sun protection should be administered far more often than insect spray.
Picaridin, which is a frequent alternative to DEET, likewise has a shelf life that is almost indefinite, but IR3535 has a shelf life of around two years before it begins to degrade.
Having said that, the majority of manufacturers, such as Ranger Ready Repellant and Off!, suggest that you throw away any insect spray that is older than three years, although the Sawyer brand offers a shelf life of ten years provided that it is kept carefully.
Natural insect sprays, the majority of which include essential oils as the active component, are more likely to lose their efficacy sooner than chemical and synthetic sprays.
Rosemary, lemongrass or citronella (with a shelf life of two to three years), thyme (with a shelf life of three to four years), and peppermint are the essential oils that are used the most often (four to five years).
Therefore, the efficacy of the repellent can begin to wane after around two years, although this is very dependent on the quantity of those oils included in the product.
Spraying a few squirts into the air and sniffing it afterward is a fast method for evaluating the effectiveness of a natural insect repellent, even if the method is not entirely reliable.
If there isn’t much of a fragrance left, it generally isn’t as potent as it previously was, especially if it hasn’t changed much over time. You won’t become sick from it, but the results may not be as good as they might be.
It is interesting to note that the federal government does not mandate that cosmetics, food, or lotions have a date of expiry (with the exception of baby food and formula), yet the Environmental Protection Agency has registered a lot of topical insect repellents (EPA).
This indicates that the firm that makes them has given the Environmental Protection Agency with technical information on the effectiveness of the product in warding off mosquitoes and/or ticks.
Spraying oneself with bug spray not only helps avoid being bitten by insects, but it also stops the transmission of diseases carried by those insects.
The Centers for Disease Control and Prevention in the United States:
Why Don’t Their Products Have Expiration Dates?
Therefore, if your insect spray does carry an expiry date, it is not required and it may be connected to other chemicals in the mixture, such as essential oils (which might start to become less effective after two years) or benzaldehyde (which only lasts about 18 months and is common in bee repellents).
Just keep in mind that there aren’t many downsides to using an old insect spray other than the fact that it won’t be nearly as effective as a fresh one, which means you may end up with a few more bug bites than you would want. Other than that, there aren’t really any other negative effects.
However, if you have any that you haven’t used in a while, the pump and tube within the bottle may be somewhat sticky with semi-coagulated spray; thus, it is recommended that you give it a good washing before using it again.
Also, if you have a bug cream or rub-on repellent, be sure to keep it out of the direct sunlight and store it in a dark place. This is particularly important for insect sprays that come in transparent bottles.
That Is Absolutely Fascinating
It is important to keep in mind that although the plastic and metal cans used for bug spray can (typically) be recycled, the actual liquid spray itself is considered to be a hazardous waste, and as such, it cannot be disposed of in a landfill.
Check with the trash management business in your area to get instructions on how to dispose of it in an appropriate manner. Therefore, rather of purchasing anything new, it is considerably simpler and more cost-effective to utilize an old bottle of insect spray.