Silicon Grease Toxicity

[PeteMcK]

I vaugely remember decades ago warnings about not getting silicon grease on your hands when applying it; Doing a search for MSDS's it seems that modern grease is non toxic.

I scavenge parts off heatsinks that have a lot of grease on them, how concerned should I be?

[SY]

It depends on the filler. Older ones with beryllium oxide ought to be approached with caution. Newer ones with zinc oxide are pretty safe, but I'd still wash my hands after using. The silicone itself is pretty nonhazardous.

[wrenchone]

Don't rub your eyes if you have the stuff on your hands - it's a mild irritant. Also, silicone heat sink goop has a strange affinity for dark clothing - beware. Commercial flux remover (such as "Flux Off") does a good job of removing it.

[PeteMcK]

Thanks guys, BeO is carcinogenic, so good reason to be careful

[kevinkr]

Originally Posted by wrenchone

<snip>Also, silicone heat sink goop has a strange affinity for dark clothing - beware. <snip>

Reassuring to hear I am not the only one victimized by this "strange affinity.."

[Coconuts 500]

Originally Posted by SY

It depends on the filler. Older ones with beryllium oxide ought to be approached with caution. Newer ones with zinc oxide are pretty safe, but I'd still wash my hands after using. The silicone itself is pretty nonhazardous.

By older, about how old do you mean? 80s? 70s?

[SY]

Good question and I don't know when there was a changeover. I'd suspect '70s, but that's just guessing.

[KatieandDad]

Zinc Oxide is used in Baby Nappy Cream so it can't be too hazardous.

Personally I always wash my hands after messing with the goo anyway.

[djQUAN]

Originally Posted by kevinkr

Reassuring to hear I am not the only one victimized by this "strange affinity.."

We wear black long sleeved jackets at work as part of the uniform. One time, I put my arm on top of a computer CPU. And surprisingly, someone left a heatsink full of goop on it.

[Ian Finch]

Originally Posted by SY

Good question and I don't know when there was a changeover. I'd suspect '70s, but that's just guessing.

We were still using BeO pads enthusiastically in the early '80s but they disappeared in a hurry around 1983, IIRC.

Such government led safety measures tend to spread pretty quickly from the first country of introduction. It's one of the few things regulators do promptly so I guess things were similar elsewhere.

The initial objection to BeO was the massive levels of inhaled dust in preparing the substance, the ceramics manufacture and handling the various moulded and ground sheet products. Dispersed in a silicone oil, you would not have the concern of dust exposure until later when the oil oozed out and migrated across surfaces as it loves to do. Handling the cheesy gunk remaining would then be some hazard for repairmen and you can well expect, for DIYs like us who like to refurbish old gear.

I'd say be real careful with how you remove and clean up the grease remains of electronics built or repaired before 1990. Use wet methods rather than dry to suppress dust and fragments spreading around. I have a couple of Mosfet amps from 79-82 that still use the ceramic pads, They won't blow, so I won't need to touch them - just as I prefer!