Child Safe Packaging Group

The Background, Current Regulations and Ideas for the Future

Date of page: Wed 13 Feb 2002 at 5:25pm

Child Resistant Packaging ??? The Background, Current Regulations and Ideas for the Future.

The Background

Child resistant (CR) packaging emerged in the early 1970???s in the United Kingdom, and slightly later throughout other European Union Countries. Initially testing, using panels of children, was undertaken only for reclosable systems; the familiar bottle and child resistant closure. It was considered then and it continued to be believed until recently that flexible, or non-reclosable packs; the familiar blister or strip, were inherently child resistant.

The standards to which reclosables needed to comply have, during the past 27years, undergone change and modernisation to conform to the changing characteristics and needs of the population. In the UK the standards were BS 5321 (1975), BS 6652 (1985) and, in its latest manifestation, ISO 8317 (2000).

Non-reclosables enjoyed the ascription of ???inherent child resistance??? until December 21st last year, through compliance with BS 7236 (1989), which did not specify child panel testing or testing by adult panels, merely materials, seal strength, seal integrity, freedom from rattle and resistance to bending. It was set out in the introduction to BS 7236 that if compliance was achieved the pack would ?????..(be) comparable to reclosable child resistant packaging in terms of child safety.???

It was easy to see that compliance with BS 7236 granted protection in the event of prosecution for breach of consumer protection legislation or the EU directive on general product safety and would provide a suitable defence in the event of any civil action. Similarly it enabled lip service to be paid to the Royal Pharmaceutical Society???s practice direction that ???..prescription medicines should be packed in child resistant containers.???

In 1997 BS EN 862 was published, this standard was subsequently updated in 2001, it is entitled ??? Packaging ??? Child Resistant Packaging ??? Requirements and Testing Procedures for Non-Reclosable Packages for Non Pharmaceutical Products.

The major sea change in the standards to which flexible packaging need to comply arose though in December 2001 with the publication of BS 8404 (2001) entitled ??? Packaging ??? Child Resistant Packaging ??? Requirements and Testing Procedures for Non-Reclosable Packages for Pharmaceutical Products.

A child resistant non-reclosable packaging standard for medicinal products has been in existence in Germany since October 1980. Its reference number is DIN 55 559 and it was up-dated in October 1998.

All four standards are intended for type approval, in other words to certify products as child resistant formed from a specified set of materials, and clearly they are not designed for QC procedures

A Discussion Concerning the Standards

All three standards dealing with non-reclosables and the standard dealing with reclosables differ in a number of respects and it is worth setting down the major areas of difference to enable us to gain an understanding of the environment of the regulatory structure. If desired a more detailed comparison can be provided or dealt with during discussion.

The Child Test

In the case of all standards the child sample consists of a maximum of 200 children aged 42 to 51 months, equal in distribution between boys and girls.

In all standards sequential testing is used, which by measuring trends enables a success or failure to be ascertained after testing a minimum of 25 individuals. This is achieved by plotting results as they occur, either above the previous result or immediately to the right of it, and when the resulting curve passes into either an acceptance or a rejection zone the pack will pass or fail. This procedure is based upon AQLs of 10% before demonstration and 15% post demonstration. LQ 20% before demonstration and 25% post demonstration with both Alpha and Beta values of 5%.

If the total sample is used, in all cases, a pack will be considered child resistant if at least 85% of the children in the test panel shall be unable to open the package without a demonstration or at least 80% of the children in the test panel shall be unable to open the package after a demonstration.

The Definition of an Opening

BS EN 862 ??? simply that the pack be opened.

DIN 55 559 ??? ???..a child is able to gain access to sufficient unit doses to cause severe injury or damage or to remove more than eight units.???

BS 84 04 ??? ?????the children are able to access more than eight units.???

ISO 8317 ??? A simple opening.

The Test Period

In the case of BS 8404, DIN 55 559 and ISO 8317 the test period is 5 minutes prior to a silent demonstration and 5 minutes after. In the case of BS EN 862 (2001) the period is 3 minutes prior to demonstration and 3 minutes after.

There is no satisfactory reason for the different test period, 3 minutes or 5 minutes, and clearly there is no satisfactory reason for the difference in the definition of an opening, viz. ??? ?????.more than 8 units??? (BS 8404) or ?????.sufficient unit doses to cause severe injury or damage.??? (DIN 55 559).

Brand owners and packer/fillers will obviously wish to act prudently in this regard.

The Adult Test

Child resistant packaging remains the only system of packaging that needs to pass a panel test for openability by adults.

In the case of BS 8404 the adult test group consists of 100 literate participants, selected randomly, between the ages of 50 and 70; 25% 50 to 54, 25% 55 to 59 and 50% 60 to 70, skewed 70% female.

In the case of BS EN 862 the adult test ??? which is optional, utilises a panel of 100, again 70% shall be female, 80% must be between 18 and 60 years of age and 20% between 61 and 65 years of age.

In the case of DIN 55 559 the adult test uses a group of 100 persons between 18 and 45 years of age, and 70 persons between 61 and 65 years of age. Again skewed 70% female to 30% male.

In the case of ISO 8317 the test panel consists of 100 adults between the ages of 50 and 70 configured identically to BS 8404 namely 25% 50 to 54, 25% 55 to 59, 50% 60 to 70 and skewed 70% female.

Passing the adult test is achieved in the following fashion.

BS 8404 ??? after a period of familiarisation 90% of the sample must be able to extract 1 unit dose within 1 minute without a demonstration.

For BS EN 862 optional adult test shall be deemed to have failed if the package cannot be opened within 5 minutes by 90% of the sample, or as specified in the sequential procedure; no demonstration is allowed.

In the case of DIN 55 559 the period for opening is 5 minutes and the failure threshold is 15%.

In the case of ISO 8317 the pack must be opened and reclosed within 1 minute without demonstration.

Again there are no good reasons other than the fact that these standards are legacy based for the lack of standardisation.

Making Blister Packs and other Non-Reclosables Child Resistant

In the United States where blister packs are less popular than in the European Union child resistance is generally achieved using a peel back and push mechanism instead of the simple push through that is the preferred European non child resistant design.

Peel back and push has a number of inherent problems when considered alongside the limitations of elderly users. According to the UK charity Age Concern, which has undertaken a programme to assist designers in assimilating the modalities of old age; it is possible to test the finger tip friction by coating the fingertips in talcum powder, this, according to Age Concern, replicates the lack of grip experienced by those between 60 and 70.

It is for this reason that blister packs using the traditional peel back and push, or merely peel back system, have not achieved popularity in the United States where the system originated and has been used since the late 1970???s.

Our organisation, the Child-Safe Packaging Group, has investigated a number of alternative designs to achieve both child resistance and senior friendliness and, at the same time, be easily manufacturable by brand owners and packer/fillers.

One of the first solutions that we considered was to utilise a label solution by adhering over the foil a security strip, which we termed ???unburstable.??? In fact it exhibited high burst but low tear strength. This was a patent originated by Doctor James Robertson, a Paediatrician and Consultant to the Child-Safe Packaging Group. Development work was undertaken by Pago Limited, the label print and label print machinery manufacturers.

The security strip system was subjected to child testing in a number of configurations using ever more aggressive adhesives. Unfortunately it did not work. The worst case scenario being generated by the security strip giving greater integrity to the foil, which instead of breaking at the first blister was torn off in its entirety thus enabling all the contents to be extracted.

We have toyed with ideas using peel back and push with a channel along the centre of a blister enabling a thumb nail to be inserted thus assisting the peel back. This is satisfactory for all those who have thumb nails!

A number of solutions have been observed that are presently being developed and these revolve around an integral box, which is itself child resistant. However, it is questionable as to whether the blisters contained within the box are child resistant and, according to BS 8404, ???..the packages should be presented to the children without the outer retail package, giving them access to the individual blister units.???

There has been discussion as to whether the child resistant outer box constitutes an integral part of the blister pack or an outer retail unit. However, the form of words, ???..access to the individual units??? is totally unequivocal, therefore an outer box that is child resistant may well qualify under ISO 8317 as a child resistant reclosable but does not qualify under BS 8404 as a non-reclosable package for pharmaceutical products.

The Concept of Child Resistance

Child resistance is achieved by creating a barrier of either dexterity or cognisance. Examples of barriers of dexterity are generally the necessity to undertake two opposing actions simultaneously, hence push down & turn the most popular child resistant closure system and squeeze & turn ??? less popular particularly with the elderly constituency.

Amongst reclosables an example of a barrier of cognisance is a ???line up the arrows??? solution, and amongst non-reclosables barriers of cognisance are achieved through an instruction ??? for example ???fold a 45?? and reveal a hidden tear start.??? Peel back and push is also a barrier of cognisance as generally a graphic or written instruction is required.

Whilst mid or end line manufacturing systems for child resistance, for example label solutions, are desirable from a cost point of view, it is debatable as to whether these will find acceptance in use by the elderly constituency. And my belief is that the European packaging supply industry can distinguish itself by developing a cognitive system of child resistance, which will defeat the attempts of children to open a package but present no difficulty for adults to of all ages to use properly.

Designing the Cognitive Solution

Our organisation the Child-Safe Packaging Group has considered a number of designs that we have either sponsored or sponsored and developed, which will create a barrier of cognisance. I am including in this section other designs which bear upon cognisance but rely upon physical attributes.

Firstly let us consider a system not originated by us but in use by Glaxo SmithKline. This is a laminate obscuring the blister but indicating the location of them. Never designed to be child resistant this system could be made so. If suitable integrity is given to the PVC and the outer foil.

Reverting briefly to a physical/cognisant barrier, we assisted in the concept of a system where a double blister pack was used but the push out portion of the blister was only exposed when compressed with an adult sized hand. Male or female, old or young the hand needed to be adult sized and a child???s hand would simply not accomplish the task. That claimed cognisance on the basis that the system was sufficiently complex as to require a written or graphic guide.

I believe that the best route forward though lies along the lines of one of our developments whereby in unit dose medicines each unit is housed within a child proof, indeed adult proof or impregnable chamber, and for extraction it needs to be encouraged along a channel into an expulsion chamber. The Child-Safe Packaging Group has sponsored a number of ideas utilising this system. It is this sort of barrier of cognisance that I believe will constitute the best route forward.

Dr James Robertson said in despair that children could tear any flexible packaging system to pieces. This may well be true but it is worth considering the testing requirements and the requirements in the real world.

1. The child sample consists of children 42 to 51 months old
2. The ingestions peak at 36 months and fall off to 5% of a normal distribution, namely 1.96 standard deviations at 42 months.

The difference in the danger range and the panel occurs through the practicalities of testing ??? you just cannot test children of 36 months. If they do not want to do as they are asked they won???t.

1. Whilst it has been observed in testing that the panel will literally tear packs apart it is necessary to consider the amount of encouragement and desire to please that is present in such testing. It has been observed that in cases of real ingestion children, not only younger than the panel, but bored and unsupervised, will explore but will not destroy packs. It is for this reason that the impenetrable or almost impenetrable initial chamber and expulsion chamber is a workable solution.

Brand owners and packer/fillers though could look again at tried and tested systems and certainly for many prescription drugs, prescribed for ???walking wounded??? for many analgesics used by ???walking wounded??? namely those people who though sick continue with their daily lives, the bottle and CRC may well be the best solution.

Unit dose packaging is unique, it protects the product not merely from the environment but from contact with other products. But where such sophisticated packaging is not required, consideration should well given to reclosable systems.

Stephen Wilkins
Wednesday, 13 February 2002
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