(by the way, can you post a link to the org?) Does your group post recommended ages and SIZES for children to be in car seats?
Mods? Would it be alright to post this link?
As for sizes/ages for seats, each state is different in it's laws for older kids, but this is what I was taught when I took the certification class.
INFANTS: MUST be in a REAR FACING seat until they are
1 year old AND at least 20 lbs. This can be either an infant carrier or a convertible seat. (Convertible seats are ones that can be rear or front facing.) Most kids will out grow the infant carriers around 5-6 months. Some earlier, some later, just depends on the weight limit of the particular seat. Most are rated up to about 22 lbs. The convertible seats are usually good rear facing from 5 lbs up to 30 or so. Some doctors will still tell parents that once their baby is 20 lbs, they can turn them front facing. This is WRONG! It's not the weight of the child so much as it is the development of muscles and bones. Also, with rear facing seats, sometimes it's difficult to get the angle of the seat right if the auto seats are deep. You can adjust this by putting a rolled up towel or section of pool noodle under the seat where it buts against the back of the auto seat. DO NOT use anything hard such as books or 2x4's. (Yes, this has been done) The point of this is that in the event of a crash, if this item were to come loose and whack someone upside the head, it won't do damage.
TODDLERS: Front facing seat WITH a harness. This can be either a front facing convertible seat or a high back booster seat WITH a harness. Generally the high back boosters with harness are rated for a child up to 40 lbs when using the harness.
BIGGER KIDS: Once a child is over 40 lbs, usually they can be in a belt positioning booster seat. (The high back boosters with harness can easily be converted simply by removing the harness straps). The child just sits in the seat and uses the seat belt like normal. These types of seats should have a couple of notches or grooves in the sides to run the shoulder portion of the seat belt through. This is to ensure that the seat belt fits the child properly. If there are arm rests on the seat, the belt (shoulder and lap) should go beneath the arm rest on the side you buckle it.
Backless booster seats can also be used. However, if the automobile seat your child sits in doesn't have a head rest and the childs head is higher than the back of the seat, they should really have a high back booster. This is to give them support in case of a crash.
In Indiana, the law for booster seats is 8 yrs/80 lbs. HOWEVER, just as an example, I have a younger sister who technically should have been in a booster seat until she was around 10 because she is small. Just because a child is 8 or older, doesn't mean that they don't have to use a booster. There is an easy way to tell if your older child needs a booster seat. Have him/her sit in the car and put their seat belt on. If the belt doesn't fit them the way it does you ( with the shoulder belt crossing the chest and not hitting the face or neck and the lap belt firmly across the hips, NOT higher on the stomach), then they need a booster. Seat belts are designed for adults, not kids. If it doesn't fit right, it won't protect right.
Now that you know the right seats class, it's time for your lesson on harness tightness. A guy I worked with always said, "Cinch it down till they can't breathe, then back off an inch." Not QUITE right but he's close. LOL The straps should be snug enough on the child that you can't pinch any loose material or be able to get more than one finger under the strap. Also, the chest clip should be at armpit level. Now....on newborns, people do this but then notice that the straps are rubbing their brand new baby's skin and so is the chest clip so then they loosen/lower everything. WRONG!!! If that is the case (and usually is on newborns) just put a bib/burprag/blanket in between their skin and the strap/clip.
Another thing before recess....all of those cute/handy/convenient products out their like the "wooly" strap covers, seat belt tightening wratchet thingies.....don't use them. It's recommended that you put nothing on a car seat that did not come with it. (Although those covers for the infant carriers that cover the baby completely are fine) Anything that could interfere with the straps or safety features of the seat is not good. Also, those roll down sun shades? Baaaaad. If there's a crash and they come loose, they hurt and can do damage if they hit someone. Use the cling ones instead. No hanging cute toys off of the handle on the infant carriers either. Same reason. Oh, and speaking of handles on the infant carriers. Most (but not all so check your owners manual) are supposed to have the handle back when in use in a car instead of straight up and down. Those seats are designed to absorb the energy of the initial impact, and then "rebound" towards the back of the car and into the back of the seat, coocooning the baby in the seat. If the handle is up it will interfere with that design and possibly severly injure the baby.
If you're not sure about weight limits, handle position, etc. for your seat, check either the owner's manual or the labels on the side of the seat. They should all have at least the weight limits for use and handle info if it's an infant seat.
Again, if you have any questions, talk to your local authorities or pm me and I should be able to head you in the right direction.