I work for a lab device manufacturing firm. During the testing of our electronic pipette according to IEC 61010-1,the safety test lab asked why it did not have the symbol indicating double insulation.

Our pipette is powered by a rechargeable battery and the DC two-pin adapter to charge the battery is provided within the box.

I know a bit about the classes of electrical products like Class I, Class II, and Class III, but I am confused about why, if the device is powered by a rechargeable battery and the DC adapter provided with the device is a two-pin adapter, it would be mandatory for the device to have double or reinforced insulation?

If the device has reinforced insulation then do we also have to place a double insulation symbol on the product? Should there be a double insulation symbol on the product itself of or is it allowed to place it on the packaging box?

Can anyone provide clarity on this topic?

  • \$\begingroup\$ Are they perhaps asking about the DC two-pin adapter to charge the battery is provided within the box not having the symbol? \$\endgroup\$ Dec 29, 2022 at 5:23
  • 1
    \$\begingroup\$ Hello Lars, They are not asking about the adapter as the adapter already has the symbol but they are asking about the product which is an electronic pipette. According to them, the pipette should also have the double insulation symbol. \$\endgroup\$
    – Harsh
    Dec 29, 2022 at 5:29
  • \$\begingroup\$ What was the answer given to the lab and what part of what specification the lab is working to suggests they are correct? \$\endgroup\$
    – Andy aka
    Dec 29, 2022 at 11:03
  • \$\begingroup\$ They have referred to clause 5.7.1 of IEC 61010-1. The answer is not given to the test lab yet. \$\endgroup\$
    – Harsh
    Dec 29, 2022 at 11:12

1 Answer 1


Double insulation might be needed for protection against electric shock (chapter 6 of 61010-1).

It says:

ACCESSIBLE parts (see 6.2) shall not be HAZARDOUS LIVE (see 6.3).

The minimum dc voltages for a circuit to potentially be hazardous live are 70V or 35V in wet locations (see 6.3).

If there are only lower voltage circuits within the device, I don't see why you would need double insulation. The charging adapter obviously needs reinforced isolation from the mains and you mentioned that this is the case along with having the corresponding symbol on it.

Using the double insulation symbol is generally optional as in 5.1.7 and forbidden if equipment is only partially protected by double insulation. So it's your call to decide if you want it to be printed on your product or not.

You could try to find out how other similar products of your company (or other companies) are labeled.

enter image description here

Equiment protected by double insulation symbol

  • \$\begingroup\$ Hello Lars, Thanks for the info. But what lab personnel saying is that there are no hazardous live parts present in the product & as the outer portion is completely made of plastic material the device is already double insulated & so the device should have the double insulation symbol on it. Is it really mandatory to have this symbol on the product? If it is not mandatory then how can we prove this point to him? Can you please suggest? Thanks. \$\endgroup\$
    – Harsh
    Dec 30, 2022 at 3:40
  • \$\begingroup\$ @Harsh Just added a small section on using the symbol. I personally find using the symbol counterintuitive in this case, because there is nothing dangerous to protect the user from. But it might be standard practice, I don't know. \$\endgroup\$ Dec 30, 2022 at 7:51
  • \$\begingroup\$ The problem is none of our competitors have this logo on their products & their products have been tested according to the same IEC 61010-1 standard. Also, their products are provided with two-pin adapters. So that's why I am unable to find the resolution to this question. But thanks for the info. \$\endgroup\$
    – Harsh
    Dec 30, 2022 at 9:28

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