One of the most important jobs parents have is to keep children safe when it comes to riding in a vehicle.

Each year thousands of children are killed or injured in car crashes. Proper use of car safety seats can help keep children safe.

But, with so many different safety seats on the market, it is no wonder many parents find their proper use overwhelming.

That is one reason the Rockingham Fire Department has a safety seat checking station from 2 to 6 p.m. every Wednesday at Station One, East Washington Street, Rockingham.

The department has eight certified Child Passenger Safety Technicians with one on duty at all times to help install seats and answer questions. For information, call 997-4002.

Child safety seats are based on the size of a child, and the requirements change as a child grows.

All infants should ride in rear-facing seats until they weigh at least 20 pounds, which is usually after the first year. Such seats cannot be used in the front passenger seat of a vehicle with an active air bag.

Infant-only seats are small and have carrying handles. Some of them are fixed to a base from which they may be removed.

A convertible or combination seat can be used rear-facing, then later “converted” to a forward-facing seat as a child grows to weigh between 20 to 40 pounds.

They are bulky and do not have carrying handles or separate bases.

It is necessary to understand from directions — or to seek help at the fire department — on the placement of harnesses that come with the seats.

Besides having such seats firmly in place to be effective, harnesses need to be in the right place in contact with a child’s body to avoid injury. Harnesses need to fit snugly against a child.

If a seat can be moved more than an inch side to side or front to back, it is not tight enough.

Forward-facing toddler seats with a harness are for children who weigh as much as 80 pounds.

Combination forward-facing booster seats can be used for children who weigh up to 65 pounds or without the harness as a booster seat up to 120 pounds.

Some vehicles come with forward-facing seats built into them.

Weight and height limits vary with all seats making it important to read the manuals which come with them or seek assistance from the fire department.

Vehicles made after 2002 should have what is known as the LATCH system, which is used to secure car safety seats in them.

Booster seats are for older children who have outgrown forward-facing car safety seats.

However, it is best for children to ride in a harnessed seat as long as possible, at least until four years of age.

If a child outgrows a seat before that age, consider using a seat with a harness approved for higher weights and heights.

One way to tell when a child outgrows a seat is when shoulders are above the top harness slots or ears have reached the top of the seat.

Booster seats raise a child up so the lap and shoulder seat belts fit properly. High-back and backless seats are available and are used with the lap and shoulder seat belts in a vehicle. They usually include a plastic tip or guide to ensure proper fit against a child.

They should be used until a child can correctly fit in lap and shoulder seat belts without them. That means a shoulder belt lies across the middle of the chest and shoulder and not the neck or throat. A lap belt should be low and snug across the upper thighs, not the belly.

Children should never tuck a shoulder belt under an arm or behind the back. Seat belts cannot be shared.

New seats should be purchased with individual needs according to a child’s size. Used seats can be dangerous if you don’t know what to look for to see if they are safe.

To find out if a seat has been recalled, call the National Highway Traffic Safety Administration Vehicle Safety Hotline at (888) 327-4236 or www.odi.nhtsa.dot.gov/cars/problems/recalls/childseat.cfm.

Always be a good role model for children by wearing a seat belt.