Greasy lego?

[arc]

I received a sealed dino attack t1 typhoon for christmas this year, and upon opening the t-rex, the arms had a grease like coat on them the left finger prints. the legs did not however.

here it is in comparison with a dino attack raptor I've had for a while.

the same thing was on the wings and legs for the pterodactyl. but it easily rubs off. so what I'm asking is has anyone else noticed this with other lego pieces? and do you know why some parts have this?

[CardinalBricks]

One time when I was about 9 I ate pizza and played with one of my sets. That's about the only time I've ever seen grease on LEGO before. That's really weird; maybe you should contact LEGO about it.

[Faefrost]

It looks like mold release residue. While we do not often see it on pieces Lego makes in house, I would not be surprised to see some on an outsourced Chinese made maxi fig. It should clean up with warm water and dish detergent using a soft toothbrush, or with alcohol. It is extremely common in plastic parts, and is why you always clean model parts thoroughly before painting or assembling a plastic model.

[LEGO Historian]

In the early days (1949-56) of slotted LEGO bricks, MRA (Mold Release Agent) was used to easily get the LEGO bricks out of their mold. In this image (the right column of bricks is modern) we see some of the MRA as a residual color on the older bricks... easily seen on white and yellow bricks...

(Image from my Unofficial LEGO Sets/Parts Collectors Guide chapter on LEGO Plastics.)