Walking through the aisles of the supermarkets for Pesach shopping brings opens you up to an entirely new world of kashrut. It is actually not new, as this has been going on for a number of years already, and it really is not limited to just Pesach-time, but the issue comes up on Pesach time more than during the year...

That is - you will find kashrut symbols with kosher lpesach status marked on many household items, and every kitchen item. That's right - everything from paper plates and dishwashing soap to bleach and garbage bags. And, just the other day I saw a picture of plungers with a hechsher - if your drain gets stopped up, you can only use a kosher lpesach plunger to  clear the blockage!

Ask any of the kashrut organizations and they will tell you that from a kahrut perspective it is really unnecessary, but the public demands it. It seems "the public" is so unsure of itself and lacks self-confidence that the public demands a hechsher on bleach and plungers so that it will be secure when it purchases these things for Pesach.

Even if they try to abscond their responsibility by saying the public demands it, rather than admitting they are fleecing the companies out of their money, and raising the cost on the products purchased by the public, they should tell the demanding public that it is not necessary and refuse to play along. The rabbis tell the public what to do about every little aspect of their private and public lives, and there is no reason that on this issue they suddenly cannot withstand the demands of the public and must give in to those demands.

Anyways, the Rabbanut is no longer playing along. The Rabbanut announced that they checked into the manufacturing process of "paper plates", throw-away dishes, and concluded that in almost none of the many types of throw-away dishes out there in the market is there a concern for chametz. Rabbi Chagai Bar-Giyora therefore said, there is no need to look for a hechsher on these products. The exception to this rule is, according to Rav Bar Giyora, baking paper and paper cups.

For a more detailed list:
aluminum: does not need a hechsher. it used to be aluminum was made with the smearing of animal fats, so it needed a hechsher. Today that is not the case, and no hechsher is needed on aluminum - not for Pesach or for the rest of the year.
paper items: no hechsher required. The issue in the past was with starches used in the manufacturing. Now they all used recycled paper products to manufacture the items, and in the process the original starches, if there were any, are broken down and removed. In the process of making the new items from the recycled products, chemicals that are inedible are used...
Absorbent paper goods: no hecher required. in Israeli-made products no wheat or corn-based starches are added, but only potato based starches.
wrapping paper: no hechsher required. for Pesach the companies switch to using potato-based starch. (I am not sure why this does not need a special hechsher. maybe somebody has some year-round wrapping paper in their house that they will use for Pesach thinking it needs no special hechsher and must be ok. who is to say everyone is going to buy the pesach wrapping paper? Also, maybe a store will continue selling its stock of paper from the rest of the year and not get the stuff made closer to pesach?)
baking paper: hechsher required for Pesach. these are manufactured abroad, and while most have no kashrut problems, some are prepared with a silicon coating and some are prepared with starches.
tablecloths: no hechsher required
paper cups: recommended to have a hechsher. inside surface is sometimes coated. usually not starch, but sometimes it is.
plastic utensils: no hechsher needed
source: Srugim and in the latest Rabbanut update

unfortunately they did not include the laundry detergents, bleaches, soaps, plungers and other items in their list and statement. And let's not forget cellphones.