Key Takeaways
It ’s always a pleasant surprise when you ’re sit on the beach or hike through anational parkonly to find that the mosquitoes , gumption fly front and ticks you wait are n’t burn . But , it ’s not so courteous to spend $ 20 or more on a full bottle of bug nebulizer , only to find that its potency has worn off when it ’s time to use it .
Fortunately , the good news is that while most bug sprays and louse repellants do die , it takes a very long time . And the exit escort — if there is one on the bottle — does n’t really mean much other than " it may not workquiteas well . "
What Bug Spray Lasts the Longest?
How long your microbe spray hold out mostly total down to its fixings that keep the bugs at bay , also get it on as the dynamic ingredients . DEET(N , N - diethyl - meta - toluamide ) is the dynamic element in many strong bug repellents , especially those used by hikers or campers in deep woods or jungles and has , theoretically , aninfinite shelf biography .
That ’s because the amount of DEET does n’t have anything to do with how well insect repellent works ; it see howlongit work . accord to theUniversity of Michigan School of Medicine , a hemipteron spray with 20 percent DEET will protect for about five hours ; spray with 7 percentage DEET will protect for two or three hours . evidently , that ’s why you should skip sunscreen - bug spray combos ; sunscreen should be appliedwaymore often than bug spray .
Picaridin — a rough-cut alternative to DEET — also has a nearly endless shelf living , and IR3535 has a shelf life of abouttwo yearsbefore it initiate breaking down .
That said , most brand , such asRanger Ready Repellantand Off ! recommend you toss any hemipterous insect sprayer that ’s elderly that three years , though Sawyer stain promises a10 - year shelf lifewhen lay in aright .
Natural bug atomiser , which primarily use substantive oils as the active ingredients , are likely to lose their effectiveness quicker than chemic and synthetic spray . The most ordinarily used essential oils are rosemary , lemongrass / citronella ( two- to three - year ledge animation ) , thyme ( three to four years ) , and red gum ( four to five age ) . So depending on the percentage of those petroleum in the repellant , you may begin to see decline in strength after about two year .
A quick — albeit not foolproof — way to quiz a natural repellant is to spray a few squirts and smell the zephyr . If it does n’t have much of a scent anymore , it ’s plausibly not as strong as it once was . It wo n’t injure you , but it just may not work quite as well .
Interestingly , there are no federal practice of law ask food or cosmetic / lotions tohave expiration dates(except for child intellectual nourishment and recipe ) , though many skin - applied repellents are register with the Environmental Protection Agency ( EPA ) . That means the ship’s company do them provide the EPA with proficient info on the safety of the product and how effective it is againstmosquitoesand / or ticks .
Why Don’t They Have Expiration Dates?
So if your bug spray does have an expiration date , it ’s voluntary and may be related to other ingredients in the mix , like essential oil ( which can bulge to become less in force after two years ) or benzaldehyde ( which only last about18 monthsand is common in bee repellents ) .
Just keep in mind , there are n’t many consequences of using an older bug spray other than it not being quite as good as a young one , so you may chance yourself with a few more hemipterous insect morsel than you ’d like .
However , if you have some you have n’t used in a while , the pump and tube inside the bottle might be a minuscule viscid with semi - coagulated spray , so you might need to rinse it well before you utilise it . And if you have a cream or rub - on hemipterous insect sprayer ( specially one with a clear feeding bottle ) , be sure to put in it out of direct sunshine , or it ’ll finally get down to dry out up .
