An electrical experiment for Easter

I was thinking further about whether manufacturers should give warnings. Generally, I view these things along the lines of a cooker having a warning which says "may get hot". May or will?

In the box of my iPhone, purchased about 13 months ago, are some leaflets in various tongues, whose wring is so small that i could barely read it. They say, "For information about charging, see "important safety information" in the iPhone User Guide."

So, how do you read the guide before you have charged the phone?

Having charged the phone by whatever means, you go online.

Philip Oakley said:

Cheap replacement chargers are the most suspicious for needing a test.

It says, "You can also charge iPhone with “Made for iPhone” or other third-party cables and power adapters that are compliant with USB 2.0 or later and with applicable country regulations and international and regional safety standards. Other adapters may not meet applicable safety standards, and charging with such adapters could pose a risk of death or injury."

And later on, "Donʼt use the power adapter in wet locations, such as near a sink, bathtub, or shower stall, and don’t connect or disconnect the power adapter with wet hands."

There's your warning, and it might get Apple off the hook in a court, but is it enough? You tell me.

Chris Pearson said:

There's your warning, and it might get Apple off the hook in a court, but is it enough? You tell me.

When I'm advising clients about hazard mitigation, for a start putting anything in the manual is a last resort (since we know hardly anyone reads them), but if you do need to then it only really works if it's right next to something they will need to read to make the whatever-it-is work. Grouping 50 safety instructions in the front of the manual, which most manufacturers do, is actually the worst pace to put them. (One or two big ones might be ok there.) 

Frankly, I think safety warnings in manuals where we know the user is not going to read those manuals - i.e. where we know they can work out for themselves how to use the device - are not credible mitigations for hazards.

Personally I don't know of any test cases for this (I probably should), but I would expect that if "the man on the Clapham omnibus" thought something was a reasonable action to take with a device, then writing in the manual that they mustn't do that would probably not constitute a reasonably practicable measure in law. Basically, I think it's unlikely to be a defence. Even if you print on the manual (as everyone does) "Important read this first".

This particular case would make an interesting test case though, as it's slightly new territory. I think if it had been, say, a mains powered radio a court would determine that the average person could be expected to know not to take that in the bath with them. But we are used to taking USB powered devices into a wider range of locations. That's the challenge with the law in this area, it's all down to what a court decides is "reasonable".

It's why I'm very glad I've never worked with domestic equipment, with "professional" equipment we can make slightly more reasoned assumptions about how the users should behave (and e.g. what they should be expected to read and follow). Not that they always do, and we still have to take that knowledge into account.

Andy Millar said:

Frankly, I think safety warnings in manuals where we know the user is not going to read those manuals - i.e. where we know they can work out for themselves how to use the device - are not credible mitigations for hazards.

Agreed. I think in answer to my own question, no it is not enough.

Andy Millar said:

the man on the Clapham omnibus

He is on his Easter holiday today, but his good friend, "the officious bystander" insisted on the warning.

There may be no caselaw because of consumer protection statutes.

R.7(2) of the General Product Safety Regulations 2005 says, "The presence of warnings does not exempt any person from compliance with the other requirements of these Regulations."

R2 (Interpretation) says, " “safe product” means a product which, under normal or reasonably foreseeable conditions of use ... does not present any risk [etc.]".

My personal view is that plugging in a USB cable when in a bath is foreseeable.

On the face of it, my experiment shows that I could do that safely with my equipment under my conditions (as GK pointed out). However, what if your charger were faulty and you suffered serious harm? I don't think that the warning would make a scrap of difference because the product is plainly not safe. Had you received a mild shock because you were sitting at your desk, the charger still would not have been safe.

Andy Millar said:

Frankly, I think safety warnings in manuals where we know the user is not going to read those manuals - i.e. where we know they can work out for themselves how to use the device - are not credible mitigations for hazards.

Agreed. I think in answer to my own question, no it is not enough.

Andy Millar said:

the man on the Clapham omnibus

He is on his Easter holiday today, but his good friend, "the officious bystander" insisted on the warning.

There may be no caselaw because of consumer protection statutes.

R.7(2) of the General Product Safety Regulations 2005 says, "The presence of warnings does not exempt any person from compliance with the other requirements of these Regulations."

R2 (Interpretation) says, " “safe product” means a product which, under normal or reasonably foreseeable conditions of use ... does not present any risk [etc.]".

My personal view is that plugging in a USB cable when in a bath is foreseeable.

On the face of it, my experiment shows that I could do that safely with my equipment under my conditions (as GK pointed out). However, what if your charger were faulty and you suffered serious harm? I don't think that the warning would make a scrap of difference because the product is plainly not safe. Had you received a mild shock because you were sitting at your desk, the charger still would not have been safe.