Yam, Kit L. (ed.). The Wiley encyclopedia of packaging technology

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is thought of as applying mainly to the setup portion of

changeover. That is important, but it applies to clean-up

as well as other areas such as documentation and material

handling.

Older home cooking ranges have individual burners

that can be time-consuming and difﬁcult to clean. Newer

ranges have a ﬂat ceramic surface that can be easily wiped

clean in a single motion. This concept can be applied to

machinery by replacing exposed nuts, with acorn nuts and

replacing exposed hex head bolts with round head bolts or,

better, ﬂat-head bolts. These provide a smoother surface,

easier to clean (Figure 4).

If walls need to be wiped down during cleaning, sys-

tems designed to facilitate this should be provided rather

than relying on rags and buckets.

Adequate and appropriate tools are a must. If me-

chanics do not have the right tool when they need it,

time is lost searching for it. Lack of the correct tool, readily

available, increases the temptation to use the wrong tool,

such as pliers. Improper tool usage not only causes delays,

it frequently damages the machine so that every future

changeover is delayed. Each machine should have a

shadow board with the correct tools needed for change-

over. The shadowboard should be located on or inside the

machine for maximum convenience.

Repetitive operations, where a large number of fasten-

ers need to be loosened or removed, may beneﬁt from the

use of power tools. Pneumatic or battery-powered wrenches

or screwdrivers should be permanently mounted at the

point of use with the appropriate bit or wrench.

Ideally, no tools at all should be used in changeover.

There are a number of devices that can be used to

substitute for bolts or other fasteners. These include

handknobs and handlevers, toggle clamps, cam locks,

magnetic, pneumatic and vacuum ﬁxturing devices, and

various types of pins.

When pneumatic, ﬂuid, or electrical connections need

to be made, they should be made by quick connects with

multiple inputs. A pneumatic cylinder requires two air

connections. If a dual quick connector is used, it not only

cuts connection time, it also makes it impossible to connect

them backwards. Connectors are available that allow

simultaneous connection of multiple electrical, control,

pneumatic, and ﬂuid supplies (Figure 5).

Photoeyes can be time-consuming and difﬁcult to reset

between products. Multiple photoeyes, one for each

product, should be permanently mounted and adjusted.

Changeover goes from requiring positioning and adjust-

ment of a photoeye by a mechanic to turning a selector

switch by an operator. Depending on the machine, this

may be done automatically via the PLC (Figure 6).

Einstein said: ‘‘Imagination is more important than

knowledge.’’ Simpliﬁcation of changeover is a good place to

turn creative imaginations loose.

EXTERNALIZE

Changeover tasks can be broken into two categories: inter-

nal and external. (These are sometimes called intrinsic and

extrinsic.) This concept was ﬁrst described by Japanese

industrial engineer Shigeo Shingo after he had been tasked

Figure 5. Multiple tube connector.

Flush fasteners facilitate cleaning

Figure 4. Flush surfaces simplify cleaning.

Figure 3. Servo driven capping chuck, with permission from

Elau Inc.

258 CHANGEOVER OF PACKAGING LINES

with reducing changeover times on stamping presses at

Toyota. Shingo documented this in detail in his book

Revolution in Manufacturing: The SMED System (2).

Internal tasks are those that are performed when the

line is stopped. External tasks are those that are per-

formed while the line is running. In almost every change-

over process, it is possible to ﬁnd tasks that may be shifted

from internal to external. They can be performed either

before or after changeover while the line is running.

One example is cleaning of the pumps on a liquid ﬁller.

If only a single set of pumps is available, these must be

removed, cleaned, and reassembled before changeover is

complete. This may extend total changeover time. If there

is an additional set of pumps, the ‘‘dirty’’ set may be

removed and set aside, and the clean set can immediately

be mounted. After the line has restarted, the other set of

pumps is cleaned and stored in readiness for the next

changeover.

Managements may object to spending money on an

additional set of pumps. They can be expensive, perhaps

$5000–10,000 per set or more. This is why it is critical for

the plant to know the costs of changeover downtime. It

is difﬁcult for management to justify the expenditure

of dollars to save minutes. It is comparing apples and

oranges and can’t be done in any meaningful way.

If costs are known, a cost–beneﬁt analysis is simple. If

having an additional set of pumps saves 15 minutes per

changeover and changeover cost is $2000/hr, the pumps

save $500/changeover. If the set cost $5000, the payback is

10 changeovers. If changeover is daily, this is a two-week

payback.

Other opportunities for externalization include:

Install additional liquid product transfer piping from

the formulating area to the line can be equipped with

clean-in-place (CIP) systems (Figure 7). This allows one

transfer line to be cleaned while the other is in use.

Organize changeparts and materials required for the

next run prior to the end of the current run. These should

be staged as close to the line as possible.

Prepare documentation, such as line clearance, setup

sheets, batch records, production orders, and the like,

during the current run.

Change out instead of changing over machines. At least

one labeler manufacturer builds machines in which the

entire labeling head is mounted on rollers. It is discon-

nected from the labeler base, and rolled out; and a

different head, which is cleaned and changed externally,

is rolled into place. Several manufacturers of ﬁllers do the

same.

EXACTLY!

The key to successful changeover is eliminating variabil-

ity from the process. This means that changeover must be

Cap sensor photoeye

Photoeye selector

Photoeye trigger-100cc

Photoeye trigger-500cc

Figure 6. Multiple photoeyes with selector switch.

Final

rinse

Wash

Pre-

rinse

Compounding room

Clean in place (CIP) system

Filling room

Transfer line

return line

transfer line

Cleaning tanks

Pump

Filler

reservoir

To filler

To drain

Main

product

supply

Figure 7. Clean-In-Place (CIP) system.

CHANGEOVER OF PACKAGING LINES 259

performed exactly the same way, to the same settings

every time. There are two components to this. The ﬁrst is

to completely describe and document what is to be done

during changeover and how. The second is to provide

measurable and repeatable setpoints for each required

adjustment. Neither is of much use without the other.

The document describing the changeover process is

often called a Standard Operating Procedure (SOP) but

will have various names in different companies and

industries. In addition to the SOP, or as part of it, a

checklist should be provided. The SOP describes, in great

detail, exactly how the changeover is to be carried out.

It should include a list of parts and materials required,

safety precautions to be taken, and tools to be used. It

will include, often as in tabular form, a complete list of all

setpoints for each product and size. Annotated photo-

graphs or diagrams should be incorporated as needed for

maximum clarity. In short, the SOP should be detailed

enough that a person with minimal training will be able to

successfully perform a changeover using it. This document

will often be too cumbersome for daily use. If it is not used,

variation in the setup will invariably result. To ensure

daily use, an abbreviated checklist is required in addition

to the SOP. This should be a one- to three-page document

detailing what is to be done. It assumes that the person is

trained, so there does not need to be much detail as to how

it is to be done.

One way to achieve this is to write the SOP as an

outline in MSWord. The major headings are the what

items with the subheadings covering the how. Once com-

plete, a table of contents can be generated showing the

major headings. This becomes the checklist.

There are many other formats that will work, and some

companies will have existing formats that must be used.

The important thing to bear in mind is that if the process

for changeover is not written down, changeover cannot be

done the same way twice. If supervisors and managers do

not continually make sure it is being followed, changeover

will not be done the same way twice.

The SOP will tell how the changeover is to be per-

formed and will document the setpoints for each adjust-

ment. This is a good start but not enough. If the tools are

not available to reliably achieve those setpoints, the SOP

cannot be reliably performed.

All adjustments must have easy and foolproof means of

measurment. These may be as simple as scribe marks on

the machine. These work but are not generally recom-

mended. They can be a source of confusion as they build up

over time. Obsolete scribe marks are difﬁcult to remove.

Scales, denominated in inch or metric, can be another

tool. The scale by itself is not enough, there must be a good

pointer to go with it. Where scales are used, they should be

in either metric or decimal inch because fractional scales

can be difﬁcult to read.

Digital indicators are available in a variety of styles. If

properly applied and mounted, they are rugged and easy

to read. The advantage to digital indicators is that they

are much harder to misread or misinterpret than the scale

(Figure 8).

Gauges, unless they are permanently mounted to the

machine, should be avoided. They can be easily mislaid.

When that happens, the machine will be adjusted, impre-

cisely, by eye. Gauges can be permanently mounted in

several styles such as a leaf gauge. This consists of several

gauges, hinged by a pin in a common mounting block. In

use, the appropriate gauge leaf is swung up and the

machine is adjusted to touch (Figure 9).

Temperature, pressure, time, and other settings should

be made using digital rather than analog controllers for

the least chance of error.

Speed is a critical parameter that is often not mea-

sured. Conveyor speeds may be set based on the position of

a single-turn potentiometer. Tachometers are a must on

all machines, including conveyors. The optimal speed of

each machine must be noted in the SOP and set during

changeover.

It is only be providing the capability of performing all

changeover tasks exactly that variability can be reduced

or eliminated.

OVERALL OPERATIONAL EFFICIENCY (OEE)

OEE is used in many plants to measure and compare line

efﬁciency. It is the product of performance, availability,

and quality. One way to improve OEE is to reduce

variability in changeover. Reducing changeover variabil-

ity impacts all three components.

Performance is improved because better changeovers

result in smoother running machinery. Smoother running

machinery will result in fewer minor stoppages.

Figure 8. Digital position indicator.

260 CHANGEOVER OF PACKAGING LINES

Availability is increased because better changeovers

will take less time.

Quality is doubly improved. Properly adjusted machin-

ery produce more closely to target parameters as well as

reducing the amount of rejected product.

Changeover of packaging lines has grown greatly in

importance in recent years. It will continue to do so as the

number and variety of products demanded by the market

increases. Ever-increasing competitive pressures mean

that it can no longer be ignored or treated as simply a

necessary evil. A company with reduced changeover times

will have a signiﬁcant market advantage over companies

with long changeovers.

Changeover must be viewed as both a tactical and a

strategic competitive opportunity.

BIBLIOGRAPHY

1. John S. McConnell, Safer than a Known Way, 2nd edition, The

Delaware Group, 1988.

2. Shigeo Shingo, A Revolution in Manufacturing: The SMED

System, (Productivity Inc., Portland, OR, 1985.

CHECKWEIGHERS

Automatic, in-line checkweighers have long been used to

perform basic weight-inspection functions. These units, as

distinguished from static, off-line check scales, perform

100% weight inspection of products in a production process

or packaging line. Furthermore, these machines perform

their functions without interrupting product ﬂow and

normally require no operator attention during production.

These charactertistics allow the machines to be used in

several different ways. The applications can be broadly

categorized as weight-regulation compliance, process con-

trol, and production reporting. This article describes a

number of checkweigher applications in these categories.

The emphasis is on problem solutions and beneﬁts,

although some description of the machine hardware and

features employed is necessary.

WEIGHT-REGULATION COMPLIANCE

The earliest use of in-line checkweighers was to help

producers guard against shipment of underweight pro-

ducts, and today various regulatory agencies set stan-

dards for weight compliance of packaged goods. Most

of these standards are adopted from recommendations

made by the National Bureau of Standards (NBS) in their

various handbooks. In general, these standards recom-

mend that the average product weight shipped by the

producer be equal to or greater than the declared weight

and that no unreasonable underweights be shipped. The

in-line checkweigher provides assurance to the producer

that these general requirements are met. With proper

adjustment of checkweigher and process, an additional

beneﬁt of reduced product giveaway can be enjoyed.

The equipment required to carry out the basic weight-

compliance requirement consists of a weighing element

(weighcell), associated setup controls and indicators, a

product transport mechanism for continuous- or intermit-

tentmotion product movement, and a reject device for

diverting off-weight items out of the production stream.

A typical machine comprising these elements is shown in

Figure 1.

The central portion of this machine shows a weighcell

consisting of a strain-gauge loadcell that is connected to

the integrally mounted electronics enclosure. Associated

6oz

16oz

10oz

12oz

Figure 9. Leaf gauge.

CHECKWEIGHERS 261

with the weighcell is a product transport, in this case

consisting of a pair of stainless-steel roller chains. Shown

on the left (upstream) side of the unit is an infeed belt

conveyor, which serves as a product-spacing (speedup)

device and ensures that only one product at a time passes

over the weighcell. On the right (downstream) side of

the unit is a channelizer product-reject device. This unit

receives signals from the checkweigher and provides a

gentle lateral displacement of rejected product by carrying

it to the side on sliding carrier plaques. Other commonly

used reject devices include air blasts, air pushers, swing

gates, and drop-through mechanisms.

Rejection of underweight products (and in some cases

overweight products, such as critical pharmaceutical

packages or expensive products) provides the required

consumer protection. The added beneﬁt to the producer

of reduced product giveaway frequently provides addi-

tional incentive to install the checkweighing machine.

The information from the typical modern checkweigher

allows the producer to control the target weight of the

process and ensures minimum average product weight,

and it minimizes rejected underweight products. The

following application example illustrates these points.

New-Contents Weight. Company A prepares a variety

of expensive frozen-food products. These products are

clearly labeled showing net-contents weight and come

under close scrutiny from regulatory agencies. Some

ingredients, such as chunky pieces, are of somewhat

nonuniform piece weight. Until an accurate in-line check-

weigher was installed, the producer was forced to overﬁll

most packages to prevent underweight shipments. The

company installed a number of checkweighers that pro-

vide the required controls. Now, by means of digital

displays and easily adjustable reject cutpoints on the

checkweigher, the processor is able to closely monitor

the ﬁlling process and establish the best compromise

between product giveaway and excessive rejects.

Product-Weight Distribution. Figure 2 illustrates a ty-

pical product-weight distribution curve before and after a

suitable checkweigher is installed.

Before checkweigher installation, the mean product

weight was maintained at approximately 293 g to ensure

against underweight shipments. After checkweigher in-

stallation, the mean product weight is reduced to approxi-

mately 289 g. This results in less than 1% underweight

rejects but saves an average of 4 g per package. The

economics of this checkweigher installation is illustrated

below:

Package labeled weight 283 g

Average overweight per package 10 g

Possible reduction in average overweight 4 g

Annual production 900,000 kg

Value of product $0.75/kg

Cost of checkweigher (including freight and

installation)

$10,000

RESULTS

Product savings 1.4%

Product saved per year 12,720 kg

Savings per year $9540

Payback period, approx. 1 yr

PROCESS CONTROL

Many products that are sold on the basis of a declared

(labeled) weight are packaged by a volumetric ﬁller or

count or other nongravimetric processes. These processes

frequently yield products of varying weight because of

product density changes. Density changes typically occur

with hygroscopic products under conditions of changing

humidity. Also, material-handling methods can cause

bulk-density changes in other products. Frequently, the

Figure 1. A typical checkweigher.

Figure 2. Weight distributions before and after checkweighing.

262 CHECKWEIGHERS

density changes occur in the form of a drift or periodic

change. These changes lend themselves well to automatic-

feedback control from a weight sensor (checkweigher)

back upstream to the process controller. Figure 3 dia-

grams a checkweigher/ﬁller feedback-control system.

This feedback loop continually adjusts the process

setpoint and maintains delivered product weight within

acceptable limits, even under conditions of density varia-

tions. These adjustments in turn reduce the long-term

weight standard deviation of the packaged products. This

allows the process setpoint to be set at a lower average

value while minimizing the number of underweight (re-

jected) packages. The result is product savings. Two

applications are described to illustrate the use of check-

weighers with feedback for process control.

Feedback Control. Company B packages a low-density,

hygroscopic product using a volumetric ﬁller. Spot checks

revealed that moisture variations from batch to batch and

humidity changes throughout the day resulted in sub-

stantial density changes. These changes often went un-

noticed until a large number of off-weight packages were

produced, which caused either excessive product giveaway

or an excessive number of underweights being rejected by

the old checkweigher. In the former case, the giveaway

represented considerable revenue loss and in the latter

case resulted in product waste due to the impracticability

of recycling and repackaging the rejected product.

The company purchased a replacement checkweigher

equipped with feedback-control features for signaling

their existing ﬁller. The checkweigher is located as close

as possible to the ﬁller to achieve maximum responsive-

ness of the feedback loop. In this case, the feedback signals

are electronically adjusting the setpoint of the ﬁller.

However, other control arrangements are possible that

include signaling a servo motor attached directly to the

control shaft of a ﬁller. This company was able to justify

purchase of the checkweighing system solely on the basis

of product savings. Figure 4 illustrates how long-term

standard deviation reduction allows lowering of average

setpoint with resultant product savings. Short-term stan-

dard deviation that results from package-to-package ﬁller

errors is inherently beyond the control capability of the

checkweigher.

Company C packages sliced luncheon meats. The ‘‘stick’’

or ‘‘load’’ of luncheon meat is fed through a slicer that

counts a preset number of slices per draft to be packaged.

Because of density changes of the meat, the correct slice

count did not always yield the declared weight of the draft

within allowable limits. With no on-line way to detect these

Figure 3. Checkweigher feedback-control to ﬁller.

CHECKWEIGHERS 263

density changes, the company had to supply an extra

number of slices to ensure labeled weight or take a chance

on packaging underweights with correct slice count. It

installed an in-line checkweighing machine that very

accurately weighs each draft of sliced meat just after it

leaves the slicer. Error signals, which represent departures

of delivered weight from target weight, are fed back to the

slicer controls. The controls in turn cause slice thickness to

be adjusted so that the preset slice count results in correct

draft weight within very narrow limits. The result was

control over the slicing process that economically justiﬁed

the checkweigher quickly.

PRODUCTION REPORTING

Automatic production reporting by a checkweigher can

provide running analysis of packaging-line performance.

Checkweigher-generated production data can be trans-

mitted to printers, computers, terminals, and other data

receivers. Whatever the reporting medium, the result

is virtually instantaneous indications of production-line

performance or automatically kept records of production

data. Productivity gains and material savings result from

such uses. Here are two applications of the checkweigher

for production recording:

Company D requires that a statistical sampling proce-

dure be carried out on each of its production lines.

Historically, quality assurance personnel periodically

removed a number of product samples from the production

line, weighed them on manual scales, recorded the

weights, and returned the samples to the production

line. Using the raw data they had collected, quality-

assurance personnel manually calculated statistical infor-

mation about the samples. From this information, they

prepared a product sampling report. Because of the fre-

quency of the sampling procedure and the number of lines

involved, a full-time quality-assurance (QA) person was

employed to perform this task. Furthermore, the manual

nature of the weighing and recording resulted in reports of

questionable accuracy.

Microprocessor-Controlled Checkweigher. The company

purchased a modern microprocessor-controlled check-

weigher that is capable of accumulating production-

weight data in real time and performing the required

sampling calculations for transmission to a printer in the

QA supervisor’s ofﬁce. Data reported to the supervisor

include data and time of report, product code, operator

identiﬁcation number, average weight, standard devia-

tion, and total weight for both accepted and rejected

product over the selected sample size. Additionally, ver-

iﬁcation of checkweigher setup parameters, such as target

weight and reject cutpoint settings, are recorded. Installa-

tion of the checkweighing system results in cost savings in

personnel for acquiring the sample data and virtually

instantaneous feedback of production data to QA and

production personnel.

Company E ships large quantities of product to custo-

mers for further processing. To corroborate material-

amount reports between supplier and customer, accurate

total production records were required. In addition to

actual weight of shipped product, an accounting of under-

weight (rejected) packages would yield important produc-

tion-efﬁciency data.

The company installed an automatic checkweighing

system and appropriate data-collection capabilities along

with a printer for location in the accounting ofﬁce. On

command, accumulated data are transmitted from the

checkweigher to the printer, which provide subtotals and

totals of average weight, total weight of product shipped

and rejected, package counts, and a ﬁgure for ‘‘yield’’

(shipped product divided by total production) on the basis

of both weight and package count. The result of this

installation is a true and accurate summary report for

the accounting department of product shipped to each of

their customers, thereby minimizing protests. The addi-

tional beneﬁt is a more accurate report of actual produc-

tion efﬁciency.

The application examples presented here describe a few

of the many kinds of packaging lines that can and should

beneﬁt from the use of in-line automatic checkweighers. A

few additional applications are suggested below:

Piece-count veriﬁcation in packages and cases

Product-safety assurance by detecting undesirable un-

derﬁlls or overﬁlls

Multizone classiﬁcation of natural products such as

chicken parts, ﬁsh, etc.

Detection of missing components in ‘‘recipe’’ food

packages

A survey of product weights in any processing/packa-

ging line may reveal opportunities for substantial

cost savings through use of an automatic

checkweigher.

BIBLIOGRAPHY

‘‘Checkweighers’’ in J. F. Jacobs ed., The Wiley Encyclopedia of

Packaging Technology, 1st edition, Ramsey Engineering Com-

pany, Icore Products, pp. 163–166.

Figure 4. Filler setpoint reduction with servo system.

264 CHECKWEIGHERS

General References

C. S. Brickenkamp, S. Hasko, and M. G. Natrilla, Checking the

Net Contents of Packaged Goods, National Bureau of Stan-

dards, Washington, DC, 1979.

C. Andres, ‘‘Microprocessor-Equipped Checkweighers,’’ Food Pro-

cess. 40, (1979).

C. Andres. ‘‘Special Report: Expanding Capabilities of Check-

weighers,’’ Food Process. 42, (1981).

N. W. Rhea, ‘‘Are You Ready For Checkweighing?,’’ Mater. Handl.

Eng. 5, (1983).

Automatic Checkweigher Test Procedure, Scale Manufacturers

Association, Inc., Washington, DC, Jan. 1977.

‘‘Checkweighing Scales,’’ Mod. Mater. Handl. 37, (1982).

U.S. Department of Commerce/National Bureau of Standards,

NBS Handbook 130, 1979 (Draft), U.S. Government Printing

Ofﬁce, Washington, DC, 1979.

U.S. Department of Commerce/National Bureau of Standards,

NBS Handbook 133, Checking the Net Contents of Packaged

Goods, U.S. Government Printing Ofﬁce, Washington, DC,

1981.

U.S. Department of Commerce/National Bureau of Standards,

NBS Handbook 44, Speciﬁcations, Tolerances, and Other

Technical Requirements for Commercial Weighing and Mea-

suring Devices, (4th edition), U.S. Government Printing Ofﬁce,

Washington, DC, 1976.

CHILD-RESISTANT PACKAGING

RICHARD WARD

Perritt Laboratories, Inc.,

Hightstown, New Jersey

Child-resistant (CR) packaging, a term synonymous with

poison-prevention packaging (PPP) and special packaging

(SP), is deﬁned as ‘‘packaging that is designed or con-

structed to be signiﬁcantly difﬁcult for children under 5

years of age to open or obtain a toxic or harmful amount of

the substance contained therein within a reasonable time

and not difﬁcult for normal adults to use properly’’ (1).

This can include hazardous substances such as drugs,

household cleaning agents, and pesticides. Packaging of

this nature may take a number of forms, including bottles,

drums, pouches, and blister packs. Many children have

been saved from bodily harm and even death as a result of

CR packaging.

HISTORICAL ASPECTS

Designs for CR packaging can be traced back to 1880,

when the ﬁrst U.S. patent was issued for a CR package.

The U.S. Congress began to take direct interest in 1966, in

response to public concern about the large number of

children gaining access to harmful substances in the

home. As a result of Congressional hearings that year,

the commissioner of the FDA appointed Dr. Edward Press

to be chairman of a committee to review the ‘‘state of the

art of safety packaging.’’ The Press committee, as it came

to be known, comprised members from U.S. industry and

government. The committee reviewed the 63 patents on

CR packaging that had been awarded between 1880 and

1966 and decided that the most realistic and practical

approach to this problem was to establish a performance

standard, using children to test the units. A series of

closure studies was conducted, involving more than 1000

panelists: adults from 18 to over 65 years of age and

children between the ages of 18 and 52 months. From

the data obtained in these studies, a protocol to evaluate

child-resistant packaging was derived. This protocol, sub-

mitted to the FDA in 1970, is reﬂected in the protocol cited

in the Code of Federal Regulations (CFR) (1), with the

exception that the Press committee protocol contained two

3-min test periods for adults, one before a demonstration

and one after a demonstration. The FDA-revised protocol,

as it appeared in the CFR, cited one 5-min test period for

adults without a demonstration. This was later changed in

1995 to a 5-min, 1-min test (2).

The U.S. Poison-Prevention Packaging Act (PPPA),

signed into law December 30, 1970, was under the jur-

isdiction of the FDA. The protocol for the evaluation of

poison-prevention packaging appeared in the Federal

in the Federal Register in 1972, ﬁrst for aspirin and then

for controlled drugs, methyl salicylate, and furniture

polish. In May 1973, jurisdiction was transferred from

the FDA to the newly formed U.S. Consumer Product

Safety Commission (CPSC), and additional products

came under regulation. The CPSC was given the respon-

sibility for medicines and household substances, and in

1979 the U.S. Environmental Protection Agency (EPA)

was delegated to administer the compliance of pesticides.

Household pesticides of a hazardous nature were regu-

lated in March 1981 (4). The initial EPA regulation was

more stringent than the CPSC regulation, but much of the

initial draft regulation was deleted to a point where the

EPA regulation (5) approximates the CPSC regulation

regarding testing requirements and standards. The major

difference between the two regulations, at this point, has

been that the CPSC regulation makes provisions for a

noncompliance package that can be used by older adults

and/or households without children, and the EPA regula-

tion does not.

EFFECT OF REGULATION

As of 2007, there were 31 substances regulated by the

CPSC. They are listed in Table 1. Regulations were placed

on these substances because of their harmful nature to

small children and the large number or severity of in-

cidences of ingestions noted. The substances appear in

this table by virtue of the ingestion patterns they have

demonstrated from the data generated by poison-control

centers located in the United States and compiled by the

CPSC. Because of the increased sophistication of data

collection since the government began collecting this

information, in some cases it is difﬁcult to measure actual

reductions in ingestions by children. However, it was

CHILD-RESISTANT PACKAGING 265

possible to present comparative ingestion data up until

1982 showing considerable ingestion reductions in many

regulated products, with reductions of up to 86% as shown

in Table 2. Currently, tables of mortality rates can be used

to demonstrate the reduction of deaths because of CR

packaging. These ﬁgures can be noted in Table 3, which

cites deaths of children under age 5 involving household

products and aspirins. This table indicates that there has

been a considerable reduction in child deaths as a result of

the ingestion of either household products or aspirins.

Testing Procedures

The ﬁrst U.S. test procedures protocol for the evaluation of

child-resistant packaging were published in the Federal

decades of experience in generating data utilizing this

protocol. Poisoning statistics have demonstrated that the

use of CR packaging aids in the reduction of child inges-

tions and deaths from harmful materials. Nevertheless, as

data gathering methodology became more sophisticated, it

appeared that there was an area still to be addressed

when it came to child-resistant packaging. It was the use

of CR packaging by older adults. This point was demon-

strated by the fact that the ingestion statistics for pre-

scription drugs showed the highest level of the regulated

products. Older adults were the major users of these

products and were thought to be contributing to child

ingestions. Further studies conducted under contract to

CPSC found this to be true (6). In interviews with these

older adults, it was found that they misuse CR packaging

often due to poor initial opening experiences. They either

did not secure the packaging properly, left the caps off

completely, or transferred their drugs to easy-to-open

unsafe containers. Recognizing that older adults had

problems opening CR packaging, the CPSC devised new

test procedures to encourage the design and manufacture

of easy-to-open so-called ‘‘senior-friendly’’ CR packaging.

Initially, the CPSC let contracts to three universities

to design new CR packaging concepts that would satisfy

‘‘senior-friendly’’ criteria, and then a mockup and a unit

cavity production package was prepared from the best

concept. From this point over a period of time, changes

were made to the test protocol to ensure that senior adults

could access newly designed packaging of the universities

Table 1. Regulated Substances—CPSC

Aspirin >45 grains

Furniture polish Z10% petroleum distillates

Methyl salicylate >5% by weight

Controlled drugs All oral forms

Na or K hydroxide Z10% by weight

Turpentine Z10% by weight

Kindling and illuminating

preparations

Z10% petroleum distillates

Methyl alcohol Z4 by weight

Sulfuric acid Z10% by weight

Prescription drugs all oral forms

Ethylene glycol Z10% by weight

Iron-containing drugs Z250 mg elemental iron

Dietary iron supplements Z250 mg elemental iron

Solvents Z10% by weight

Acetaminophen >1000 mg acetaminophen

Diphenhydramine >66 mg diphenhydramine

Glue removers >500 mg acetonitrile

Permanent-wave neutralizers >600 mg Na bromate

>50 mg K bromate

Ibuproﬁn >1000 mg ibuproﬁn

Loperamide >0.45 mg loperamide

Lidocaine (April 10, 1996) Z5mg

Dibucaine (April 10, 1996) Z0.5 mg

Mouthwash (ethanol) Z3g

Naproxen sodium (February 6,

1996)

Z20 mg

Ketoprofen >50 mg

Fluoride >50 mg elemental ﬂuoride

+ >0.5% elemental ﬂuoride

Minoxidil >14 mg

Methacrylic acid >5%

OTC drugs From prescription drug

Low-viscosity hydrocarbons 10% or more by weight and

viscosity >100 SUS at

1001F

Table 2. A Comparison of the Number of Regulated Substances by Children Under 5 Years Old

Regulated Substances Effective

Year

Ingestions During the

Effective Year

Ingestions During

1982

Decrease Since

Effective Year (%)

Aspirin 1972 8146 1753 78

Controlled drugs 1972 1810 541 70

Methyl salicylate 1972 161 49 70

Furniture polishes 1972 697 229 67

Illuminating and kindling preparations 1973 1736 452 74

Turpentine 1973 777 110 86

Lye preparations 1973 508 69 86

Sulfuric acid

1973 7 1 86

Methanol

1973 37 21 44

Prescription drugs (oral) 1974 4180 2251 46

Ethylene glycol 1974 138 59 57

Iron preparations 1977 359 163 55

Paint solvents 1977 641 180 72

Acetaminophen 1980 1511 1118 26

Since these ﬁgures are based on a few cases, the percent decrease may not be reliable.

266 CHILD-RESISTANT PACKAGING

design as well as packaging designed by individual in-

ventors and designs developed within the packaging

industry. Concepts that were devised included ones that

required cognitive skills to activate. That is, they relied on

the mental ability of the adults to determine how to open

units versus high forces as push and turn or pull as have

been required with the ongoing type CR packaging

systems. In addition to the new cognitive skill concepts,

package manufacturers reﬁned their current CR packa-

ging design to make them easier to open for senior adults

yet still difﬁcult for children.

The ﬁrst U.S. CR packaging test procedure (protocol)

appeared in the Federal Register in the spring of 1971, and

this protocol was adhered to up until the summer of 1995,

at which time a new and modiﬁed CR protocol appeared in

the Federal Register. The original 1971 protocol cited the

need to employ 200 children between the ages of 42 and 51

months of age equally divided according to age and sex

with an allowance of 10% variance, and also 100 adults

between the ages of 18 and 45 years representing 70

women and 30 men. The children were to be tested in

pairs in familiar surroundings and would have two 5-min

test periods, one without a demonstration and one with a

demonstration and they were told they could use their

teeth if they had not used them in the ﬁrst 5-min test

period. The adults were allowed a 5-min test period and

were told that they should open and resecure (if appro-

priate) the packaging according to the directions.

Standards for the children were set as 85% unsuccess-

ful before demonstration and 80% total after demonstra-

tion. Ninety percent of the adults had to open and close (if

appropriate) the package in a 5-min test period.

The 1995 CR protocol takes into consideration a num-

ber of features that have been observed over the years that

would help standardize the testing procedure from one

test agency to the next. In addition, it includes major

changes in the ages of the adult test group. These features

will be discussed later. The ages of the child panelists has

remained 42–51 months, but instead of immediately uti-

lizing a group of 200 children, 42–51 months of age, the

test is conducted in groups of 50 children on a sequential

basis up to 200 if it is required according to an established

pass–continue–fail pattern based upon package openings

(see Table 4). In order to make it easier to obtain child

panelists, the number of chronological groupings has been

changed from 10 to 3. The three selected groups are to

include

30%

40%

30%

42–44 months of age

45–48 months of age

49–51 months of age

Table 3. Deaths of Children Under Age 5 Involving Household Products

Deaths Due to All Household Chemicals Deaths Due to Aspirin Products

Year No. deaths Decline (%) Since 1972 Year No. deaths Decline (%) Since 1972

1972 216 — 1972 46 —

1973 149 31 1973 26 43

1974 135 38 1974 24 48

1975 114 47 1975 17 63

1976 105 51 1976 25 46

1977 94 56 1977 11 76

1978 81 63 1978 13 72

1979 78 64 1979 8 83

1980 73 66 1980 12 74

1981 55 75 1981 6 87

1982 67 69 1982 5 89

1983 55 75 1983 7 85

1984 64 70 1984 7 85

1985 56 74 1985 0 100

1986 59 73 1986 2 96

1987 31 86 1987 3 93

1988 42 81 1988 3 93

1989 55 75 1989 2 96

1990 49 77 1990 1 98

1991 62 71 1991 2 96

1992 42 81 1992 0 100

1993 50 77 1993 2 96

1994 34 84 1994 1 98

1995 29 87 — — —

1996 47 78 — — —

1997 22 90 — — —

1998 26 88 — — —

1999 29 87 — — —

2000 28 87 — — —

Data obtained from the National Center for Health Statistics in Washington, DC.

CHILD-RESISTANT PACKAGING 267