Emergency stop devices: the risks of installer liability

This entry is part 10 of 13 in the series Emer­gency Stop

On the MachineBuilding.net blog today, Alex D’Arcy, Sales Direc­tor at Hylec-APL pro­vides some inter­est­ing insights into the lia­bil­i­ties asso­ci­at­ed with the instal­la­tion of emer­gency stop devices on machin­ery. Hylec-APL pro­vides tech­ni­cal prod­ucts and solu­tions in the field of indus­tri­al machin­ery and emer­gency stop sys­tems. Check out Alex’s arti­cle.

If you need to know more about the tech­ni­cal design side of emer­gency stop sys­tems, there are a num­ber of tech­ni­cal arti­cles on the top­ic on this blog.

The Third Level of the Hierarchy: Information for Use

This entry is part 3 of 3 in the series Hier­ar­chy of Con­trols

I’ve writ­ten about the Hier­ar­chy of Con­trols in past posts, but I’ve focused on the ‘engi­neer­ing’ side of the con­trol equa­tion: Phys­i­cal changes to machine design to elim­i­nate haz­ards, and mechan­i­cal or elec­tri­cal con­trol sys­tems that can reduce risk.

The first two lev­els of the Hier­ar­chy, Elimination/Substitution and Engi­neer­ing Con­trols, are typ­i­cal­ly more chal­leng­ing to apply in most people’s minds, because expert knowl­edge is required. These lev­els are also more effec­tive in con­trol­ling risk than the sub­se­quent lev­els.

The Third Level

iStock_000009386795Small - Photo of Instruction manualThe third lev­el of the Hier­ar­chy is ‘Infor­ma­tion for Use’, some­times abbre­vi­at­ed as ‘IFU.’ This lev­el is decep­tive­ly sim­ple, and is fre­quent­ly the lev­el peo­ple want to jump to when the oth­er con­trols seem too dif­fi­cult to imple­ment. Done well, infor­ma­tion for use can make a sig­nif­i­cant con­tri­bu­tion to risk con­trol. Unfor­tu­nate­ly, it’s done poor­ly or not at all more often than it’s done well.

Infor­ma­tion for use includes:

  • Instruc­tions and Man­u­als;
  • Oper­a­tor Device tags and Leg­end Plates;
  • HMI screens;
  • Haz­ard Warn­ing signs and labels;
  • Train­ing Mate­ri­als (text, video, audio) and Train­ing (face-to-face, webi­na­rs, self-direct­ed);
  • Sales and mar­ket­ing mate­ri­als.

Infor­ma­tion for use is need­ed in all the stages of the prod­uct life cycle: Trans­porta­tion, Instal­la­tion, Com­mis­sion­ing, Use, Main­te­nance, Ser­vice, Decom­mis­sion­ing and Dis­pos­al [1]. At each stage in the life cycle, the con­tent of the infor­ma­tion and the pre­sen­ta­tion may be dif­fer­ent. In every stage it can make a sig­nif­i­cant con­tri­bu­tion to risk reduc­tion by com­mu­ni­cat­ing the safe approach to the tasks in that stage, and the risks relat­ed to those tasks. The infor­ma­tion should include the intend­ed use and the fore­see­able mis­us­es of the prod­uct. This is a legal require­ment in the EU [2], and is a best-prac­tice in North Amer­i­ca.

In this arti­cle I’m going to focus on instruc­tion man­u­als. If you’re inter­est­ed in Haz­ard Warn­ings, includ­ing signs, labels, and inte­gra­tion into man­u­als and instruc­tions, watch for a future post on this top­ic.

Legal requirements and standards

In the Euro­pean Union, the legal oblig­a­tion to pro­vide infor­ma­tion with a prod­uct is enshrined in law [2].
No North Amer­i­can juris­dic­tions make an explic­it require­ment for instruc­tions or infor­ma­tion for use in law, but many prod­uct spe­cif­ic stan­dards include require­ments for the con­tent of man­u­als.

CSA Z432 [3] out­lines require­ments for con­tent in Clause 17, and in EN 60204–1 [7]. IEC 62079 [4], pro­vides guid­ance on the design and pre­sen­ta­tion of instruc­tions. ANSI Z535.6 [5], pro­vides spe­cif­ic instruc­tions on inclu­sion of haz­ard warn­ings in man­u­als and instruc­tions.

Train­ing require­ments are also dis­cussed in CSA Z432 [3], Clause 18.

5% Dis­count on ISO and IEC Stan­dards with code: CC2011

In the USA, pro­vid­ing infor­ma­tion for use with a prod­uct is con­sid­ered to be sound ‘due dili­gence’, how­ev­er, pro­vid­ing infor­ma­tion on resid­ual risk is often seen by lia­bil­i­ty lawyers as dan­ger­ous, since man­u­fac­tur­ers are pro­vid­ing infor­ma­tion, in writ­ing, that their prod­uct is not ‘per­fect­ly safe.’ If you’ve read any­thing I’ve writ­ten on risk assess­ment, you’ll know that there is no such state as ‘per­fect­ly safe.’ If a haz­ard exists, a poten­tial for harm exists, a prob­a­bil­i­ty can be assessed and thus risk exists, how­ev­er remote that risk may be. I think that this argu­ment by some lia­bil­i­ty lawyers is fatu­ous at best.

Ken­neth Ross, one of the lead­ing prod­uct lia­bil­i­ty lawyers in the USA, dis­cuss­es the require­ments for warn­ings and instruc­tions in an arti­cle pub­lished in 2007 [6]. In the arti­cle, he explains the US require­ments:

Prod­uct sell­ers must pro­vide “rea­son­able warn­ings and instruc­tions” about their prod­ucts’ risks. The law dif­fer­en­ti­ates warn­ings and instruc­tions as fol­lows:

Warn­ings alert users and con­sumers to the exis­tence and nature of prod­uct risks so that they can pre­vent harm either by appro­pri­ate con­duct dur­ing use or con­sump­tion or by choos­ing not to use or con­sume.”

Instruc­tions “inform per­sons how to use and con­sume prod­ucts safe­ly.”

A court has held that warn­ings, stand­ing alone, may have no prac­ti­cal rel­e­vance with­out instruc­tions and that instruc­tions with­out warn­ings may not be ade­quate.

There­fore, when the law talks about the “duty to warn,” it includes warn­ings on prod­ucts in the form of warn­ing labels; safe­ty infor­ma­tion in instruc­tions; instruc­tions that affir­ma­tive­ly describe how to use a prod­uct safe­ly; and safe­ty infor­ma­tion in oth­er means of com­mu­ni­ca­tion such as videos, adver­tis­ing, cat­a­logs and web­sites.

The law says that a man­u­fac­tur­er has a duty to warn where: (1) the prod­uct is dan­ger­ous; (2) the dan­ger is or should be known by the man­u­fac­tur­er; (3) the dan­ger is present when the prod­uct is used in the usu­al and expect­ed man­ner; and (4) the dan­ger is not obvi­ous or well known to the user.”

Read Mr. Ross’ lat­est arti­cle on warn­ings.

This prac­ti­cal and sen­si­ble approach is very sim­i­lar to that in the EU. Note the require­ment that “instruc­tions that affir­ma­tive­ly describe how to use a prod­uct safe­ly.” The  old list of “don’ts” doesn’t cut it — you must tell your user how to use the prod­uct in an affir­ma­tive way.

Second Best

So why is it that so many man­u­fac­tur­ers set­tle for man­u­als that are bare­ly ‘sec­ond best’? In many com­pa­nies, the doc­u­men­ta­tion func­tion is:

  • not seen to add val­ue to the prod­uct;
  • not under­stood to have legal import in lim­it­ing prod­uct lia­bil­i­ty;
  • giv­en lit­tle effort.

The per­cep­tion seems to be that man­u­als are pro­duced pri­mar­i­ly to fill fil­ing cab­i­nets and that cus­tomers don’t use the infor­ma­tion pro­vid­ed. This leads to man­u­als that are writ­ten after-the-fact by engi­neers, or worse, the role of ‘tech­ni­cal writer’ is seen to be an entry lev­el posi­tion often filled by interns or co-op stu­dents, with lit­tle over­sight by qual­i­fied peo­ple.

End-user train­ing is fre­quent­ly giv­en even less thought than the man­u­als. When designed togeth­er, the man­u­al will sup­port the train­ing pro­gram, and the train­ers can use the man­u­al as one of the pri­ma­ry train­ing tools. This pro­vides con­ti­nu­ity, and ensures that the train­ing process is prop­er­ly doc­u­ment­ed.

iStock_000012657812Small - Techncial ManualMy expe­ri­ence is that few engi­neers are excel­lent writ­ers. There are some, no doubt. Writ­ing man­u­als takes a sound under­stand­ing of edu­ca­tion­al the­o­ry, includ­ing an under­stand­ing of the audi­ence to whom the mate­r­i­al is direct­ed. The lev­el of tech­ni­cal sophis­ti­ca­tion required for a sim­ple house­hold prod­uct is com­plete­ly dif­fer­ent from that required for the tech­ni­cal sup­port man­u­al for an indus­tri­al weld­ing laser.
The engi­neers design­ing and inte­grat­ing an indus­tri­al sys­tem are often too close to the design of the prod­uct to be able to write effec­tive­ly to the tar­get audi­ence. Assump­tions about the lev­el of edu­ca­tion that the user will have are often incor­rect, and key steps may be skipped because they are assumed to be ‘com­mon knowl­edge.’

Qual­i­ty doc­u­men­ta­tion is also a cus­tomer ser­vice issue. Prod­ucts that are well doc­u­ment­ed require less cus­tomer ser­vice sup­port, and when cus­tomers do need sup­port, they are gen­er­al­ly more sat­is­fied with the result.

New Delivery Methods

The deliv­ery meth­ods for tech­ni­cal doc­u­ments have changed con­sid­er­ably in recent years. Large, ring-bound paper man­u­als are being dis­placed by on-line, inter­ac­tive doc­u­men­ta­tion that can be accessed at the user inter­face. The use of PDF-for­mat man­u­als has jumped, and this brings in the abil­i­ty to link error mes­sages gen­er­at­ed by the con­trol sys­tem to the sec­tions of the man­u­al that relat­ed to that aspect of the sys­tem. Video and ani­ma­tions can be added that pro­vide at-a-glance under­stand­ing of the oper­a­tion of the machin­ery. WiFi net­works in indus­tri­al facil­i­ties, along with the accep­tance of mobile pad-com­put­ing devices like the Apple iPad, mean users can have the instruc­tions where they need them, and tech­ni­cians and ser­vice per­son­nel can take the man­u­al with them to the area where a prob­lem exists, and can use the doc­u­ments even in very low-light con­di­tions.

Find­ing tech­ni­cal writ­ing resources can be a chal­lenge, par­tic­u­lar­ly if you are look­ing to move away from paper to elec­tron­ic doc­u­men­ta­tion. The stan­dards men­tioned in this arti­cle are a good place to start.
Doc­u­men­ta­tion can range from writ­ing through tech­ni­cal illus­tra­tions, ani­ma­tion and video pro­duc­tion. Find­ing indi­vid­u­als who can pro­vide you with pro­fes­sion­al ser­vices in these areas in a time­ly way and at a rea­son­able price is not an easy task. If you need assis­tance rang­ing from a few ques­tions that need answers to hir­ing a tech­ni­cal writer, Com­pli­ance InSight Con­sult­ing can help. Con­tact me for more infor­ma­tion!

Are your prod­uct man­u­als as good as they could be? What kinds of chal­lenges have you had with get­ting them writ­ten, or used? Add your com­ments below!


5% Dis­count on ISO and IEC Stan­dards with code: CC2011

[1]    “Safe­ty of machin­ery — Gen­er­al prin­ci­ples for design — Risk assess­ment and risk reduc­tion”, ISO Stan­dard 12100, 2010

[2]    “DIRECTIVE 2006/42/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 17 May 2006 on machin­ery, and amend­ing Direc­tive 95/16/EC”, Annex 1, Clause 1.7, Euro­pean Com­mis­sion, 2006.

[3]    “Safe­guard­ing of Machin­ery”, CSA Stan­dard Z432, Cana­di­an Stan­dards Asso­ci­a­tion, 2004.

[4]    “Prepa­ra­tion of instruc­tions – Struc­tur­ing, con­tent and pre­sen­ta­tion”, IEC Stan­dard 62079, Inter­na­tion­al Elec­trotech­ni­cal Com­mis­sion, 2001.

[5]    “Amer­i­can Nation­al Stan­dard For Prod­uct Safe­ty Infor­ma­tion in Prod­uct Man­u­als, Instruc­tions, and Oth­er Col­lat­er­al Mate­ri­als”, ANSI Stan­dard Z535.6, Amer­i­can Nation­al Stan­dards Insti­tute, 2006.

[6]    K. Ross. “Dan­ger! The Legal Duty to Warn and Instruct”, Risk Man­age­ment Mag­a­zine, [web] 2007, Avail­able: No longer avail­able.

[7]      “Safe­ty of machin­ery — Elec­tri­cal equip­ment of machines — Part 1: Gen­er­al require­ments”, CENELEC Stan­dard EN 60204–1, CENELEC, 2009.