Maxi-Cosi i-Size


Main FAQs about i-Size

1. What is i-Size?

i-Size is new EU legislation that increases the safety level of child car seats, and so provides improved protection for children in cars. i-Size will be ratified on 9th July 2013. i-Size does not replace the current car seat regulation ECE R44/04, but will run side by side with it for the foreseeable future.
i-Size key points:
- Improved protection at higher forces for side & front impact and a much better protection of head and neck, with the addition of side impact testing as part of the i-Size regulation
- Rearward facing travel is mandatory up to 15 months old for i-Size car seats
- i-Size promotes ISOFIX*, which has less chance of being incorrectly fitted than belted car seats
- i-Size car seats will fit all i-Size cars and almost all cars with ISOFIX
- Length/Height of child classification (instead of weight) makes choosing the right car seat easier

*ISOFIX is an international standardized fitting system, which provides a safe, easy and quick way to install a child car seat without the need for car seat belts. The name ISOFIX stands for ISO (International Standardization Organization) plus FIX (Fixation). ISOFIX car seats make use of two standard attachment points at the base of the vehicle seat, plus an additional anti-rotation device to prevent forward pitching: this can be either a support leg or top tether. 

From 2006, most new cars have been equipped with ISOFIX and a top tether anchor point. ISOFIX is also fitted in a large number of car brands built prior to 2006. From 2011, all new cars are equipped with ISOFIX. 

2. Why has i-Size been developed?

i-Size has been developed to further increase the safety level for children transported in cars in Europe. 

Many parents move their baby to a forward-facing car seat too early, typically at around 9 months (group 1 from 9kgs – 18kgs). This is because the current regulation uses a confusing weight-group classification that can be mistakenly understood to allow moving your baby to a forward facing car seat at 9 months. Many parents mistakenly believe that the child outgrows the seat when their feet stick out of the seat shell. This premature switch from rearward - to forward facing, places the child in greater danger of head and neck injury because the baby’s neck is not yet developed enough to support their relatively heavy head.
Also, the current EU legislation (ECE R44/04) does not provide performance criteria for side-impact collisions. 

The new regulation promotes ISOFIX, which has less chance of being incorrectly fitted than belted car seats. It requires to travel at least up to 15 months rearward-facing in i-Size car seats and includes a minimum performance requirement for side-impact collisions. 

3.  As of when is the new legislation effective? 

Phase 1 of i-Size becomes effective on the 9th of July 2013. As of this date it is possible for car seat manufacturers to test their products to the new i-Size regulation and to sell them to consumers.

There will be further developments to the i-Size regulation at a later stage covering children of a taller length classification. Phase 2 of i-Size is expected to become effective sometime during 2014. Information on phase 3 of i-Size will be released at a later stage.

4. Does i-Size replace the current ECE R44/04 legislation?

i-Size is introduced as new legislation and will run side by side with the current ECE R44/04 for the foreseeable future. This means that, for now, new car seats can still be tested to ECE R44/04 and consumers can still use the ECE R44/04 products.

Both i-Size and ECE R44/04 are laws. Meaning that manufacturers such as Maxi-Cosi can choose to make either i-Size and/or ECE R44/04 car seats. Likewise, consumers can choose to either buy an i-Size car seat or an ECE R44/04 car seat .

5. What is the difference between i-Size and the current ECE R44/04?

The differences between the current ECE R44/04 and i-Size are summarised in the table below:

i-Size check list

ECE R44/04


1. Improved protection at higher forces for side & front impact and a much better protection of head and neck

Front impact 50km/hr – 21-28G

Rear impact 30km/hr – 14-21G

No side impact

□ Front impact 50km/hr – 21-28G

□ Rear impact 30km/hr – 14-21G

□ Side impact: 24km/hr – 13-15G with an intruding door

2. Rearward facing travel is mandatory up to 15 months old for i-Size car seats

Forward facing possible from 9kg (approx. 9 months)

□ Label on the product: rearward facing up to 15 months (for i-Size car seats)

3. i-Size promotes ISOFIX, which has less chance of being incorrectly fitted than belted car seats

IsoFix, belt and combination

All weight groups

□ Phase 1 i-Size: IsoFix only & birth to 105cm/0-4 years

4. i-Size car seats will fit all i-Size cars and almost all cars with ISOFIX

1.Universal (top tether)

2.Semi universal (support leg)

3.Car specific

□ Universal (support leg & top tether)

5. Length/Height of child classification makes choosing the right car seat easier

Current seats are categorised under  6 different weight based group: Group 0, 0+, 0-1,1, 1/2/3, 2-3

No groups

□ Length classification(cm based)

□ Rearward facing mandatory up to 15 months

6. Why is it safer to transport a child up to 15 months rearward facing rather than forward facing?

Up until 15 months, the baby’s neck is not developed enough yet to withstand the forces of an average frontal collision because of their relatively heavy head. The excessive pressure on the neck of the baby might lead to serious neck injury. When travelling rearward facing, the forces of a frontal collision are better spread over a greater area of the body of the baby, which leads to less pressure on the head and neck.

The biggest leap in safety enhancement can be achieved by prolonging rearward facing travelling until 15 months (compared to 9 months in many cases). As of 15 months, the neck is more developed and withstands the forces in forward collision better.

It is important to note that Maxi-Cosi recommends to use car seats as long as possible rearward facing. New car seats that are currently being developed by Maxi-Cosi will allow for rearward facing travelling up until 4 years.

7. Are there also i-Size cars being developed? How does this affect the fitting of car seats in cars?

i-Size cars are being developed at the same time as i-Size car seats. Since the 9th of July, the automotive industry has been able to test their cars according to the i-Size regulation. i-Size though is not mandatory for car manufacturers, while ISOFIX is.

One of the advantages of the i-Size legislation is that the automotive industry is also involved, resulting in better compatibility between car seats and cars: all i-Size car seats will fit all i-Size cars. For non i-Size cars with ISOFIX fixing anchor points, the correct fitting is also improved but must still be checked against a compatibility list

8. What is the effect of side-airbags on travelling rearward facing? 

Side-airbags have no negative effect on child restraint systems, whether they are used in rearward or forward facing mode. In some but not all cases of a side-impact collision, the side-airbag will provide additional safety for the child.

Frontal airbags do have a negative impact on the safety of rearward facing transported children. The airbags have to always be switched off when travelling rearward facing on the front passenger seat. Maxi-Cosi recommends not to use a rearward facing car seat on the front passenger seat, even when the airbag is de-activated. 

9. If rearward facing travel is safer, are current ECE R44/04 forward-facing group 1 car seats not safe anymore?

All forward facing group 1 car seats tested to ECE R44/04 are still safe to use, however they do not offer the additional support to the head and neck that rearward facing travel offers. These products are also tested by independent test institutes such as STIWA, ADAC, ANWB, ÖAMTC and TCS. Many of these tests also include side-impact parameters. Maxi-Cosi has established an advanced Technical Center in France which also includes a crash sled for crash testing. In this center all products are tested extensively on frontal and side- impact and misuse. Maxi-Cosi introduced side-protection-systems into its car seats several years ago, and has been carrying out its own voluntary testing on ECE R44/04 seats for many years

The current ECE R44/04 car seats are totally safe while new i-Size seats that allow rearward facing longer can be called even safer.

10. Why has the classification of car seats changed from weight to length of the child? Why not make the up-sizing decision based on the child’s age?

The child’s length is a better scale to determine the fit in a car seat than weight or age. There is a lot of variation between the length of children and their age. Children are known to grow differently, as they can have growth spurts at different times.

Age and kilos can still be used as an indication to the fit in a car seat next to the length. Length however will be the main denominator since it tells best if a child fits a seat well and when a parent should switch to the next car seat. The exception to this is the point at which you can change from rearward to forward facing travel which is 15 months minimum.

11. Why does the i-Size legislation not use minimal length for rearward facing but 15 months instead?

This is because research[1] has shown that on average the neck of a 15 month old child is developed enough to withstand the forces of a forward collision. This is based on the child’s age and not his length or weight

[1] Casper 2007, Accident reconstructions

12. What will Maxi-Cosi do to enable longer rearward facing travelling?

Maxi-Cosi has been highly active in establishing the new i-Size legislation. Thereby, all manufacturers will be obliged in the future to enable longer rearward facing travelling with their products.

Maxi-Cosi 2way Family expected to launch autumn 2013 will allow rearward facing travel up to 4 years. 

13. Why do parents currently move their child to the next stage car seat too early?

It is known that parents are eager to switch from rearward to forward facing seats since this enables the baby to interact more with other car passengers. A common misinterpretation is the 9kg limit for forward facing that is often mistakenly understood as 9 months. Another misunderstanding is that parents think that the child has outgrown the child seat when the child’s feet stick out of the child seat. Only when the baby’s head sticks out of the top of the baby car seat or when the baby reaches 13kg , should parents move the baby to the next stage car seat. (see below diagram)


i-Size dictates that rearward facing travel is mandatory up to 15 months which removes any doubts as to when the child should be changed from the rearward to forward facing position.

14. Who has been involved in defining the new i-Size legislation? What is the role of Maxi-Cosi in this process?

The European Union has formed a committee  that has defined the i-Size legislation. All the following parties are involved in the development of i-Size:

Dorel is the parent company of Maxi-Cosi. Representatives of Dorel form part of the i-Size task group. As a long-time and leading manufacturer of child car seats, Dorel has established an advanced Technical Centre in France. This center encompasses everything necessary to conceive, design, build and test car seats in a modern, state-of-the-art facility. This facility, along with Dorel’s experience and expertise in child seat design and manufacture were deployed by the UNECE (United Nations Economic Commission for Europe) to help develop and define the new i-Size regulation.



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