Introduction to Isofix
Referring to the installation of child car seats, ISOFIX stands for “International Standards Organisation FIX” and is intended to make the fitting of child seats quick and simple using extremely safe and secure fixings within your car’s passenger seat system. When cars are manufactured, ISOFIX points are built into them to enable ISOFIX child seats to be simply plugged into them, removing the need for grasping the complex system of securing child seats with the traditional seat belt fittings. So many people have had difficulty in fitting child seats correctly, and, worryingly, countless surveys have demonstrated a high proportion of child car seats being incorrectly fitted which renders them unsafe.
Since car seats have different shapes, seat belts have different lengths and the position of the anchor points are in different places, it is almost impossible to manufacture a child car seat that fits all cars, and this effects the ability to secure a child car seat correctly.
Thankfully, ISOFIX was designed to solve all these problems, since any ISOFIX child car seat that you buy is designed to plug straight into the ISOFIX points, eliminating the need to fix a seat belt around it.
ISOFIX has another important benefit – its super-solid fixings create a rigid link between the child seat and the car to provide extra security.
It is required that all new cars are fitted with ISOFIX points, but it is still essential to ensure that any ISOFIX seats are approved for your car, since it is not yet the case that an ISOFIX seat will fit in every car with ISOFIX points.
Originally, ISOFIX was devised as a standard, universal means of attaching child restraints and eliminate mis-fitting problems common with the use of adult seat belts, as well as to improve dynamic performance of child restraints as the seat is directly and rigidly attached to the car structure. Although these objectives have been met, unfortunately the system is still quite complicated to use as cars don’t all have the same ISOFIX fixings and the seats are not all ‘universal’. Your car’s manufacturer, or the child seat retailer, should both be able to advise you on which ISOFIX seats can be used in your car. It is highly advisable to test the seat out in your car before you make your purchase.
With an ISOFIX system, the two latches at the back of the child car seat prevent it from moving forwards but it is the car seat cushion itself that will be supporting the weight of the child seat. Therefore, if the cushion is too soft, the child seat could rotate forwards in a crash which would increase the impact on the child and, ultimately, the risk of injury. To prevent this, a ‘universal’ child seat requires a third rigid point of attachment, either in the form of a rigid support leg between the front of the child seat and the floor of the car, or a ‘top tether’ strap, which connects the top of the car seat to a fixing point provided by the car manufacturer.
The earlier cars fitted with ISOFIX anchorages offered a two-point system only. Since the car seat cushion plays a crucial role in the performance of the child car seat these are restricted for use only with ISOFIX child car seats that have been specifically approved for use in that car – semi-universal or vehicle specific ISOFIX seats.
In the most recent years, new models of car have been manufactured with two or more seating positions provided with ‘three-point’ ISOFIX anchorages – two-point plus top-tether – which has made them suitable for ‘universal category’ ISOFIX child seats, and giving these car drivers a much easier task of choosing the right car seat.
There are two different categories of ISOFIX seat, ‘universal’ and ’semi-universal’/vehicle specific, and now there are several different size classes to differentiate between different sizes of car. These are:
A – ISO/F3: full height forward facing toddler child restraint
B – ISO/F2: reduced height forward facing toddler child restraint
B1 – ISO/F2X: reduced height forward facing toddler child restraint
C – ISO/R3: full size, rearward facing toddler child restraint
D – ISO/R2: reduced size rearward facing toddler child restraint
E – ISO/R1: rearward facing infant child restraint
The best advice is to check your vehicle handbook first before you embark on the purchase of an ISOFIX child seat. It should give you detailed information regarding the categories (Universal/semi-universal/model specific) and size classes of ISOFIX child restraint that may be used, as well as providing clear instructions for attaching a child seat to the lower anchorage points and, if provided, to the top-tether mechanism too.
