Practical Advice for the Design of Child Resistant Packaging

1. Get information about design options in good time.

In more than 30 years of existence, we have come across a lot of very effective safety features and some that were not effective.

The design of child resistant packaging is based on the fact that children at the relevant age of 42 to 51 months are not fully capable of performing two movements - push and turn - at the same time and in a coordinated manner.

Consequently the point is not to develop closures which are generally difficult to open, but which require two coordinated movements to be performed simultaneously. This requirement can be met by several designs which differ significantly in convenience, safety and expense. Careful planning can help to make packaging a success - for the safety of children and for the benefit of the company. This is especially the case when a new safety mechanism is to be developed.

2. Do not think of children's hands alone.

Especially senior citizens often have difficulties in opening child resistant packages.

This is due to a lack of strength or agility which many older consumers have to contend with. As tests conducted over the last 30 years show, the problem encountered in earlier days, namely understanding the opening mechanism, has become unimportant nowadays. Even the critical test group of senior citizens aged 60 to 70 takes only two to five seconds to open a child resistant packaging if the opening requires little physical effort. The opening mechanism is understood immediately.

3. Prevent wear.

The longer deflection has another important benefit. It permits the use of larger lock cams with greater overlap. This makes it harder for children to open the package and prevents the fragile cam tips from wearing off quickly, if the package is used improperly. The wear of cams is one of the main problems that makes the child resistant system of "squeeze and turn" closures fail from time to time.

4. Round and round.

The risk of cam wear is reduced if the lock cams on the bottleneck and inside the cap are not pointed, but rather rounded or almost spherical. The child resistant function will last longer. Rounded lock cams combined with a long cap deflection are a very effective closure system for plastic packaging containers. This provides good child resistance, but is easy to open for adults.

5. Think big.

The small hands of children can grab small-diameter closures more easily and so do their teeth. Small diameters are inconvenient for the hands of adults anyway, because the radii are smaller and thus permit only designs with small deflections, which means that more force must be exerted to remove the closure. Wider closures are easier to use for adults, and at the same time they are just the type of closure that is hard to open for children.

6. Listen to the “click”.

Testing how easy or hard it is to reseal a package is part of the standardised adult testing procedure, because the hazardous product must be kept safe also after its first opening. There are numerous packages, however, that make it difficult for non-professionals to be sure that the closure is sealed correctly. As a result, the closure is either left half-open or screwed on so tight, that a lot of physical effort is needed to remove it. A clicking noise signalling that the closure has been safely resealed is a fine convenience feature.

7. Use leverage.

Regarding "push down and turn" closures it is important to make sure that the outer part of the closure is always pushed up again. This task is performed by small levers inside the two-piece closure. Many levers make the opening smooth and easy and ensure life-long child resistance. Accurate spacing between the two closure parts prevents the closure from getting stuck.

8. Watch out for the triangle.

The typical weak point of tab packaging is the transition area from the welds to the nominal film thickness. Small triangular reinforcements placed at the points where the welds meet give significantly better results.

9. "Once bitten, twice shy..."

You should not rely on that! Children often attack packagings with their teeth, especially film packagings for tabs. There are relatively "bite-resistant" films which prevent a child from getting to the toxic contents.

Please don't hesitate to contact us even before you start developing a child resistant packaging. We might help you to avoid mistakes from the very beginning and avoid major costs.

10. Think outside the box.

While adults open blisters by pressing down the pill or tablet, tests have shown that only 50 per cent of all infants use the same method. They rather try to destroy the back film with their fingernails; they try to pick off the film and remove the pills. Hard and solid films have been developed to prevent that. It is equally efficient to adapt the shape of the pills to the cavities.

 

11. Blister shape and films.

Flat pills and tablets that fit exactly into the cavities have turned out to be safer in tests with children than oval-shaped or round pills, especially if these are packaged in cavities too large. Blister cards with small, flat pills that fill out the cavities completely are safe even if they have a relatively thin back film. Even back films made of paper have proven good. Oval and long pills and cavities offer more targets for childrens’ hands because of the leverage. The same is true for pills that don’t fill out the cavities, it is then easier for infants to pick off the film.

 

12. Flexibility is the key

Children often try to open blisters by twisting them. Therefore combining the right materials is especially important in order to prevent the lidding film from tearing. The more flexible the back film, the more difficult it is for infants to open. Perforations will keep children away from the pills and tablets because when a child twists a perforated blister, the blister will fall apart.

 

13. Peel Push for security and convenience

Peel Push films are suitable for child resistant packaging as well as convenient for the elderly. The double film is equipped with a hidden slit where the pills are to be removed. By bending the film, the slit becomes visible and the content can be removed easily. If you are in the beginnings of the construction of child resistant packaging, our associate company, IPC International Packaging Consulting, is pleased to advise you at any time and without obligation. The staff of IPC is specialised in child resistance and especially in convenient packaging for senior citizens. The IPC staff can help you avoid errors from the start and thus avoid the risk of enormous expenses. In a word: Play safe.

If you would like more information about the certification of child resistant packaging, please contact us for any further requests without obligation.