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Children's Hospital at Dartmouth Hitchcock (CHad)
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Child Safety Seat FAQ

What is the law in New Hampshire?

Everyone under age 18 must use a seat belt or child safety seat. Effective January 1, 2014 each child under age 7 or 57 inches tall (whichever is reached first) is required to use a child safety seat. The safety seat can be a seat with a harness or a booster seat.

Until the child's seventh birthday they are required to use a child safety seat.  If the child is 57 inches tall before their seventh birthday, they are only required to use a seat belt.

Best practice is for a child to use a child safety seat until the seat belt fits them properly which is usually when they reach 4 foot 9 inches tall.

When can I move my child from one seat to another?

The American Academy of Pediatrics and the National Highway Traffic Safety Administration recommend keeping children rear-facing as long as possible, using a seat with a harness as long as possible, and using a booster until the child can safety fit with seat belt only. Each step away from rear-facing with the harness reduces the protection for a child.

Rear-facing to forward-facing

Keep a child rear-facing until at least 2 years old AND until the child out grows the rear-facing seat by either weight or height. The child's head must be at least an inch of the top of the child safety seat. The child must be at least one year old and 20 pounds. Rear-facing with a harness provides the most protection for a child. High back Boosters are always preferred.

Forward-facing to booster

Use a seat with a harness for as long as possible. Harness limits range from 40 to 90 pounds. Be sure the child is within the height and weight limits of the child safety seat. Use of a harness provides more protection for the child. When the child reaches the limit of the harness by height or weight and is mature enough to use only the booster with the lap/shoulder belt, then the child can move to the booster seat.

Booster seat to seat belt

Use a booster seat when the child has reached the limit of the height or weight limit of the harness and is mature enough to remain in their seating position with the booster seat.

The booster seat must be used with a lap and shoulder belt. Booster seat purpose is to raise the child up for a better fit of the seat belt.

When is a child ready to use only the seat belt?

  1. Can your child sit all the way back against the vehicle seat?
  2. Do your child's knees bend comfortably at the edge of the vehicle seat?
  3. Do the child's feet touch the floor?
  4. Does the belt cross the shoulder between the neck and arm?
  5. Is the lap belt as low as possible, touching the thighs?
  6. Can the child stay seated like this for the whole trip?

If you answered NO to any of these questions, your child is not ready to use only the seat belt. Use a booster seat or other child safety seat. Keep your child safe!

Which is better the booster with or without a back?

Choose a booster seat that provides the most protection for your child. Purpose of the booster is to raise the child up for the seat belt to fit properly.

Booster seats without backs are fine as long as there is some protection for the child's neck and head. The head restraint in the vehicle can provide this protection.

Booster seat with a back protects the child's neck and head. A booster with a back keeps the child in the correct position for the seat belt to do its job if there is a crash.

Without the back on a booster children often lean on doors which could pose a danger in a crash. If the child is leaning on the door and a side air bag deploys it could cause injury. If the child is in the seating position with a booster sitting up straight and the air bag deployed there is no danger.

My child's safety seat says it goes up to 110 lbs. Can I use the harness up to this weight?

Be sure to read the instructions and labels on the child safety seat. Every seat will have limits on the weight and height for each position. For instance, a seat may be rated for use with a harness up to 50 lbs. and then can be used without the harness up to 110 lbs.

How do I get my child's safety seat checked?

Contact a Child Passenger Safety Inspection Station to schedule an appointment.

Are you looking for a new car seat but overwhelmed by the choices and worried about how to properly install your car seat?

The National Highway Traffic Safety Administration has rated each child safety seat according to its Ease of Use. Check out how car seat features differ among various models.

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