Mythbusting Archive

Mythbusters: Can Infant Car Seats “Click” Into Shopping Carts?


Anyone who has had a baby in an infant car seat has faced the grocery store dilemma- what to do with baby while you’re shopping? Especially a sleeping baby. And I know we’ve all seen what seems like the easiest answer- putting the infant seat, with baby, into the top part of the grocery basket.

There are signs posted on the infant seat and virtually every car seat manual says that you shouldn’t do this, but, is it really as unsafe as the signs lead us to believe? Is there a reason we can’t make use of this incredibly useful position for baby? Let’s find out.

MYTH: Infant car seats can safely “click” into the tops of shopping carts if you hear an audible “click.”

First, I would like to clarify that yes, there once was a seat that specified in the manual that you could do this (the Baby Trend Flex-Loc), however, the current manual does not allow it. So let’s set aside that seat/manual for the remainder of this discussion because it’s no longer true of that model of car seat.

As CPSTs, we counsel parents on this one quite a bit, mostly because nearly every infant seat manual specifically states not to put the car seat on top of the shopping cart. But do we know that it’s actually dangerous? The answer is sort of.

The Consumer Product Safety Commission has put forth a document describing the injuries to children related to grocery charts from birth to age of 5. Within that report, they state that

“Of the 12 incidents reported as falls, three involved a car seat with the child in it falling from the shopping cart; of these three incidents, one was a fatality and one involved a hospitalization. The fatality occurred when a 3-month-old boy fell while secured in a car seat that was not secured to the shopping cart after the cart was pushed over a speed bump in the parking lot.”

More on that terrible tragedy in a moment. It further states that,

“There were nine incidents coded as “other,” covering a range of hazards. Five of the reports concerned failures or inadequacies of the restraints in the shopping cart seat (including one involving a car seat); none resulted in injuries.”

So, it’s clear that a car seat improperly placed on a grocery cart can cause injury to an infant. Upon further searching, the single death cited by the CPSC did involve an infant seat in the top of the grocery cart. In a news report on the child’s death they report that the seat was placed in the part of the car closest to the push bar, where a toddler might sit, which is precisely the myth we are discussing.

Just in terms of design, a cart can be very top heavy if not properly balanced. Anyone who has tried to stand on the bottom basket while pushing has felt that tipping motion and you can imagine if you have a 20 pound child in a 12 pound car seat, it wouldn’t take much for the cart to tip and the child to be injured. But I think there’s another piece to consider.

Your rear facing only car seat is made to click into one style base. You cannot put a Graco infant seat in a Chicco base because the locking mechanisms are not interchangeable. And the same is true for an infant seat and a grocery cart. You may hear an audible “click” but that does not mean that the seat is actually locked in because you have no way of knowing if the shape of the grocery cart is similar to the shape of your infant seat base. The part of this is that because the shape of a grocery cart won’t be the same as the shape of your base, trying to click it onto the cart might actually ruin the locking mechanism of your car seat. And you wouldn’t necessarily be able to see that or know that it wasn’t working until it was stressed by a crash.

Yet another hazard is a potentially broken shopping cart. The carts are used by dozens of people each day and they will break down over time. How terrifying would it be if this was your car seat with your child in it?

And last but not least, car seats are not meant to be used for long durations outside of the car. I know it’s convenient, believe me, I’m guilty of using my car seat for a few more errands than I should, but that doesn’t mean it’s safe. Car seats are meant to be at a very specific angle and if they are too upright, as they often are in strollers and grocery carts (especially when in the top of the cart) baby may not be able to breathe properly. And, obviously less seriously, excessive use of infant car seats can result in flattening of the back of baby’s head (brachycephaly), which may require use of a head orthosis to correct later on.

VERDICT: Between every manual and grocery cart forbidding it, the CPSC report and the potential to break your car seat, I think we can call this one BUSTED. Even if your car seat seems to “click” into the cart, that doesn’t mean it’s safe to be left there.

If you need to take your baby grocery shopping, you have a few safer options than the top of the cart. You can wear baby in a carrier or sling, you can bring baby in a regular stroller and use the stroller basket as your cart (this is what we do the most), or if you really need to use your infant car seat, you can place it in the big part of the grocery cart and put the rest of the groceries elsewhere. But the best option in my opinion is to get someone to babysit so you can stroll the aisles, childfree, as if you’re on vacation. Not that I do that or anything!

Please please please, don’t put your infant car seat in the top of a grocery cart. It may seem secure, but it only takes a split second for your infant to become a statistic.

Mythbusters: Are Backseat Baby Mirrors Deadly?

Myth: Backseat baby mirrors present a life threatening danger specifically as a projectile in a crash.

There are a lot of black and white things about child passenger safety. Always read the manual. Always follow the manual. Chest clip always goes at armpit height. Harness should always pass the pinch test. But when you get outside of those black and whites, you’ll find that there’s a lot of gray. And that gray can be almost exclusively be explained as parental discretion. As CPS Technicians we can give you suggestions about things that may or may not be dangerous, but we don’t always have the hard evidence for these things like we do for the black and white things.

One such gray area are the mirrors that attach to the rear vehicle seat head restraints so that parents can see their rear facing babies and toddlers (and preschoolers!). There are some CPS Techs who will tell every single parent that these are patently unsafe and are a projectile. Other CPS Techs use them in their own vehicles. So which is it – are they deadly projectiles or perfectly safe? Or neither?


Alright, so let’s look at the science:

Well. Technically there is none. No studies on this to cite, no federal safety standards that mirrors have to pass in order to be sold, but I don’t think that means we can’t come to a decision based on evidence. Let’s look more abstractly at the science. Specifically, how does speed impact the effect a projectile can have on a child? For this, we have to go back to high school physics. The force an object exerts is equal to that object’s mass times its acceleration. So let’s apply this to mirrors.

Based on a quick Amazon search, the average weight of a mirror is around 1 pound, which is equal to .45kg. So let’s say you were hit while traveling 30 miles per hour or 13.41 meters per second (for simplicity’s sake we’re going to say this happened in 1 second. This is not mathematically accurate, I am aware). If Force = mass x acceleration, the force of the mirror would be equal to .45kg x 13.41m/s, which comes out to 6.03N (newton). I know what you’re thinking. Cool math, Katie. But what does it mean?

What is 6N in real life? What does any of this mean?

6N is equivalent to the force of hitting your child with a 5 pound object traveling at 5 miles per hour. Or throwing 10 pound object at your child traveling 3 miles per hour. Those all exert the same force and it’s not a trivial amount of force.

Don’t worry, I’m not going to linger on the math. Basically, an object exerts more force when it’s moving quickly than when slowly, so a 1 pound mirror seems pretty insignificant, but when it’s traveling at 40 miles per hour, it will dramatically increase the force it exerts on whatever it hits.

But, is it deadly?

Well, for it to strike the child, first, it would have dislodge from the vehicle headrest. There are a variety of ways that mirrors attach to the headrest. Some attach to the vehicle top tethers, others buckle or hook to plastic hooks around the top or back of the headrest. There is a chance that these attachments could break or fail in a crash, and logically, it would be more likely for a heavy mirror, like the ones with batteries and moving lights and music speakers, to break from its attachment than a light one (back to that force equation- the heavier mirrors impart more force, so the straps have to be able to restrain them).

Assuming the mirror did dislodge, the injury to the child would depend greatly upon the speed of the crash, the weight of the mirror and I would also argue the design of the mirror is also worth considering. Obviously a heavy mirror will exert more force and a lighter one less and a faster crash will likewise increase force, and a slower force will increase it less. But I think we also need to consider that a mirror with a thick plastic edge is likely going to result in a more significant injury than a mirror with a soft/padded edge just due to the way it will strike a person, even if it is with the same amount of force.


After a solid google search, I haven’t been able to find mention of any injuries from backseat mirrors and certainly no fatalities from them. In terms of physical injuries caused by mirrors, I think we are left to assume that it is possible for a child to be injured by a poorly attached heavy mirror that becomes dislodged in a crash at a high speed.

Before we rule on this myth, are there other dangers we’re not considering with regard to mirrors?

As a CPS Technician who makes the personal choice to use a mirror, I can tell you without question that they can be distracting. It’s easy to spend just an extra second checking to see if baby is asleep and in that second, if the traffic ahead of you stopped suddenly, you would be at risk for a significant collision. Likewise it’s easy to miss hazards in the road, someone changing their lane into yours, etc. Anytime you take your eyes off the road, you put yourself and your child at risk. I personally believe (and again, I’m not anti-mirror, I use one in my vehicle) that a parent can be distracted enough by a backseat mirror to cause a crash.

So, what about our myth?

Verdict: This myth is a tough one. We have no scientific proof that it has happened or will happen, but I think when looking at the physics, it is PLAUSIBLE.

As a CPS Technician, I tell parents fairly frequently that I do not recommend using mirrors, but if they are going to, there are a few things they can do to lower the risks associated. First, make sure you pick one that is as lightweight as possible. There are several that are lightweight plastic with soft edges. I’m not endorsing any particular product but some appear to be less risky than others.


Second, make sure that it is well attached to your vehicle head restraint. Again, designs and attachment systems vary a lot from one product to the next and some appear more secure than others. Give it a good hard tug and decide if you think that it would stay put in a 30 mile per hour crash.

And, most importantly, I think, remember that it is a distraction and that distracted driving is deadly driving. If you’re going to use a mirror, check it as briefly and sparingly as possible. If you find that you are getting distracted by it, take it off. If you don’t give your children food or toys with small parts you don’t have to worry about choking and other car seat issues can be triaged when you arrive at your destination or take a pit stop.

I’m sorry we weren’t able to get a more clear answer on this, but I think that it’s an important topic to discuss. Please feel free to offer other suggestions or information you may have found in the comments section.

Mythbusters: It is safe to place your infant seat on the top portion of a shopping cart


In this Mythbusters article I’m going to touch on something that’s been discussed before. It may be somewhat of a rerun but given the incredibly common practice I think it’s due time.

Myth – It is safe to place your infant seat on the top portion of a shopping cart, especially when it clicks into place.

Car-Seat-on-top-of-shopping-cartMany people view this as truth because, well, everyone does it. Surely if it is that awful and dangerous then you wouldn’t see every infant in the store chilling in their car seat on the cart every time you go to Target, right? Plus it clicks in! It’s meant to be placed there!

This next paragraph may be a total spoiler but I suspect you already know the answer anyway since I’m running a blog post on it.

According to the Consumer Product Safety Commission (, between 2008 and 2012 there were approximately 107,300 shopping cart related injuries treated in kids under  the age of 5. Of these cases, 85% were head/facial injuries. The American Academy of Pediatrics shows that, between 2003 and 2007, approximately 43,562 infants were treated in emergency rooms for being injured while in a car seat that was not in use in a vehicle. 84.3% were head injuries, the majority of them being due to either the infant falling out of the car seat or the car seat falling from an elevated surface.


I know the following scenarios are disturbing to imagine, but I feel like they will illustrate how easy this can happen to anyone.

Case 1: You just wrapped up grocery shopping. Your baby is snoozing happily in his infant seat on the cart.  You’re pushing the cart through the parking lot to your car and you cruise over a speed bump. The infant seat that clicked perfectly into that spot on the cart 30 minutes earlier pops off the cart and topples to the ground. Your sweet baby slams head first onto the pavement from 4 feet up in the air, with the additional weight of the car seat on top of him.

Case 2: You’re shopping at Target with your newborn and your crazy toddler. You have your baby in his car seat on the cart but you ALWAYS have one hand on him. Except when your toddler knocks off some containers of baby puffs from the shelf on the floor. You bend over for just a second to pick them up. Your toddler wants to kiss your baby’s feet and pulls up on the cart handle to reach. The cart tips over and the baby goes face first onto the concrete floor, cart on top of him, not to mention the crush your toddler is going to get too.

Sadly, I didn’t make those up.

If you want to spare yourself the nightmare, please use the car seat IN THE CAR. Not outside of it. I know it’s handy when they’re napping, but it’s just so easy to temporarily sit them on a counter, a table, or a shopping cart. Yes they make little docks on shopping carts designed for infant seats, but shopping carts tip so unbelievably easy that it’s just not worth the risk. If you need to place a car seat in a shopping cart then place it in the big part of the cart. I know that defeats the purpose of the cart, but that’s really the only solution here.

Obviously this myth is busted. Break the cycle and share with those you know. Your kid is going to have plenty of opportunities to get hurt…here’s one you can avoid.


Mythbusters: Vehicle headrests are meant to break vehicle windows


Every once in a while, a meme goes around on Facebook that catches my attention. And one such meme has been making the rounds on my friends’ profiles. For some reason, this one has been wildly popular and everyone seems to be very excited about the implications and benefits of this information.


And it has gotten me wondering. Is this true? Because if so, I had no idea and what a great hidden trick! If not, then it is probably sort of dangerous for people to be spreading it to others when there are devices that are specifically created to help break windows in an emergency.

So let’s get to some myth busting or maybe confirming this time?

MYTH: A vehicle headrest is left deliberately detachable and sharp so that it can be used to break a vehicle’s window and the glass of a vehicle window is easily broken from the inside.

I’m going to break this down into two parts: the headrest and the window.

Let’s look first at the major function of a headrest. It’s part of the restraint system and anyone who is using a backless booster or a seatbelt alone, absolutely should have a headrest. It is critically important for preventing neck hyperextension in a crash and could be the difference between a spinal cord injury and just normal whiplash. So that’s its primary function. Now what about the window breaking?

I did some poking around the internet and found a very long (and dull) document about headrest function and design written by NHTSA. Despite being at least 10 pages long, there is nothing in it about the potential to break vehicle windows.

The other thing that leads me to believe that this part of the myth may not be true is that not every vehicle has removable headrests. It seems like if this was part of an industry standard, then there wouldn’t be these outliers with non-detachable headrests. And I took off the headrests of both of my cars and sadly, neither were sharp.

I’m going to go ahead and say that a vehicle headrest isn’t left deliberately detachable or sharp for window breaking. It is potentially a major bonus (if it can indeed break a window), but it is not a part of the primary design of the vehicle seat in anything I’ve found.

Now, to the second part: whether vehicle glass easy to break. I really felt strongly that the answer to that was no, but there is definitely a lot to learn about vehicle glass.

FMVSS 205 — This sets clear standards for automotive window transparency and the strength of automotive glass required to keep occupants inside the vehicle during accidents. That right there, sounds like strong glass, right?

The windshield is made of laminated glass, where the side windows are tempered glass. Laminated glass is two layers of glass with a layer of polyvinyl butyral in the middle. The PVB allows the glass to absorb energy and makes it stronger than typical glass, which both helps maintain the roof space in a roll over and prevents passengers from being ejected through the windshield. I strongly suspect that laminated glass would not yield to a vehicle headrest prong.

Tempered glass is glass that is heated and quickly cooled. What this does is allow the outside layers, which are cooler, to contract and compress, but the inside, which is still hot, is able to expand, making the glass extremely strong both when put until tensile and compressive forces. Tempered glass is somewhere between 5 and 10 times stronger than standard glass. While this process makes strong glass, it does make the edges weaker, which is why those edges are ground and smoothed down (look at the top of your windows to see what I’m talking about). Might this weakness be how a vehicle headrest can break a vehicle window? Arguably yes, but! let’s look again at our myth.

It states that the vehicle headrest is deliberately detachable so it can be used to break a vehicle window, which we’ve already found to be dubious at best, and that the vehicle window is easily broken from the inside. The way that the tempered and laminated glasses are created is entirely for the opposite purpose. These glasses are intended to be exceptionally strong: to hold the frame of the car stable, to keep occupants inside, to withstand the concussive force of the passenger airbag. Nothing about the design of laminated or tempered glass is in any way easy to break.

Verdict: This myth, as it is written, is busted.

Now, before you comment with the video of the woman breaking her window open with the vehicle headrest, which I have seen, know that I’m not saying that it is impossible. I’m simply saying that, per this meme, a vehicle headrest is not created with this intention in mind and that vehicle glass is very intentionally hard to break. And more importantly, there are several tools on the market that will reliably and much more easily break your window open in a crash and you should absolutely have at least one of these in your car. Many will double as seatbelt cutters and could literally save your life in a crash involving water or a heavily damaged door.

belt cutter1



In the end, I’m hoping that this meme will slowly die, or perhaps be replaced with one that includes information about belt cutter/window breaking kits so that more families don’t have to hope their headrests come off or that they can get the exact right leverage to break their window in an emergency. Let’s not rely on hoping that vehicle companies imagined this secondary benefit of a headrest and instead spend the $5 for peace of mind and confidence that you have the ability to escape after a crash.