Hi, Corey,

Thank you for this information. It is very useful. While I did not 
"discover" D5, I have perhaps done more than anyone else to raise 
awareness that it is an interesting liquid for tape re-lubrication. I 
was originally pointed in that direction by Scott Dorsey.

I have added MSDS links on my page (several days ago as I said I would 
in the thread) saving people from Googling.

My use of D5 is NOT constant. I use it less than once per week on 
average. I have not seen 50 ppm in the MSDS sheets that I have looked 
at, but let's see how that works out because I'm curious.

My studio is approximately 11 x 13 x 7.5 feet or a bit over 1,000 cu ft. 
That translates into 335 x 396 x 228 cm or a volume a bit over 
30,000,000 cu cm. 1 cu cm = 1 ml.

My normal "dosage" for a cassette is about 5 ml that dissipates over a 
few hours. Assuming it all evaporates into the air at once, that is an 
exposure level of 0.2 ppm. Let's assume I'm really sloppy with a reel 
tape and use one ounce (30 ml) of D5 and that it all evaporates at once. 
Here I end up with 1 ppm.

I do have mechanical ventilation on my studio. There is a supply fan and 
an exhaust fan. I usually keep them well throttled back for noise 
reasons (I meet NC25 with one computer and both fans running low) so 
let's assume that the average rate of air replacement is about 50 cfm. 
That means that I replace the air completely every four hours or less. 
The volume of the house is about 667,000,000 cu cm providing a further 
22 x dilution if no outside air is replaced. At this point, I suspect 
that the house exchanges outside air at least four times per day--more 
in the fall and spring--so I do not see any real chance of buildup of D5 
to even 50 ppm.

I currently have less than 5 l of D5 in the house and if all of that 
were to evaporate at once, the average concentration in the house would 
be 8 ppm.

Obviously local doses would be higher.

The lethal dose for 50 % of the rabbits tested was >16 ml/kg. Assuming 
that I weigh 100 kg and that I have the same sensitivity to contact as 
rabbits, that would require 1.6 l of D5 to be absorbed through my skin. 
I think that is unlikely to happen. Isopropyl alcohol is equally toxic 
(12.8 g/kg in rabbits -- please note that the MSDS for this which I link 
on the D5 page specifies it as 12,800 mg/kg which makes it LOOK much 
safer) which is very close to the 16 ml/kg for D5 (factoring in that 
isopropyl is lighter than D5). I wonder if the test is stopped at 16 
ml/kg and that's why the D5 sheet says > 16 ml/kg???

This EU report shows a much higher LD50 number 

The above-referenced EU report notes that, on average, cosmetic and 
personal care products that contain D4/D5 or some combination thereof 
contain about 8.3 %, The highest concentration noted was 45 % in a 
stick-type antiperspirant with rouge powder at a maximum of 33.6% (pp 

So, using the 8.3 % average concentration means that for every 12 g or 
12 ml of the product you APPLY DIRECTLY TO YOUR BODY, you are applying 1 
g or 1 ml of D4/D5.

Both the EU and the Canadian report (referenced in the blog post) seem 
to think that D5 is safe in its personal care role but needs to be 
watched for long-term environmental effects.

Please note that I would be concerned working around D5 in a 
dry-cleaning establishment, but no where near as concerned as with 
earlier chemicals that were used.

I'm not being cavalier but I am also not being alarmist. Everyone must 
make up their own minds about the relative safety. It is good to think 
about workplace safety, but at least my studio allows me to use D5 
without worrying about coming anywhere near the 50 ppm exposure level. 
My relative infrequent usage of the technique also helps in this regard.

One of the unknowns is tape baking and at this point I am recommending 
the use of a "range hood" type exhaust fan to remove the materials that 
are evaporated off the tapes during the baking process.

As an aside, when I had the Mt. St. Helens seismic tapes here, I could 
smell the presumed-to-be whale-oil lubricants until about a month after 
the tapes were removed. It was very faint, but I could smell 
them...through the cardboard boxes that they were packed in!

Thanks again for the discussion.



On 2012-10-17 3:14 AM, Corey Bailey wrote:
> Hi Jeff,
> Apologies for the delayed reply.
> During the early 1990’s, I experimented with various chemicals and
> off-the-shelf products looking for the holy grail of lubricants for analog tape
> and magnetic film suffering from binder hydrolyses and other forms of degradation.
> D5:
> I’ve never used D5. I’ve only had some discussions with Richard Hess about this
> particular chemical. However, my concerns are; according to the MSDS, D5 should
> be limited to an exposure level of 50ppm (Parts per Million) and Richard uses
> this stuff at full strength. The MSDS also recommends vented eye protection,
> respirator, etc. I can send you the MSDS off list if you are interested. My
> other concern with D5 is the possible effects on the oxide for long term
> storage. Richard Hess discovered D5 for use as a lubricant for magnetic media and is the resident authority on its use.
> IPA:
> Marie O'Connell's method works. I tried something similar during my 1990’s experiments
> and had good results. My experimental method consisted of applying the IPA with
> a large eye dropper directly onto the tape oxide while in play mode. The erase and record
> heads acted as a squeegee and problem tapes played surprisingly well. My
> concern at the time was the amount of IPA that was getting into the electronics.
> Marie has modified her machines so that the IPA is contained. IPA is not harmful to tape oxide and since it evaporates completely, there should be no adverse effects on long term storage. Marie would be the authority here on observed long term effects, if any.
> What I use is Last factory lubricants:
> This lubricant is safe to handle (MSDS is available) and has
> no long term consequences that I have been able to discover. According to the
> company, their lubricants will enhance the shelf life of analog tape. I have
> used it on hundreds of analog tapes and magnetic film elements with great
> success (about 95%). According to Walt Davies at Last Factory, I was the first
> to try their product on magnetic film.
> This stuff is expensive and if you have a large collection
> or do a large volume of tape transfers, it could get costly. I simply build it
> into the cost of doing business.
> Some other products I’ve tried with success:
> Zecote
> This is a lubricant designed to lubricate film for use in
> projectors. It can be aggressive on oxide if used excessively. I’m not sure if
> Zecote is still available.
> Filmguard;
> Also a lubricant designed to lubricate film for use in
> projectors however, it is touted as safe for magnetic oxide. My findings have
> been that it works well and has no immediate adverse effects. It does leave a
> residue on the oxide which makes me wary of its long term effects on stored
> media.
> Jojoba oil:
> Organic, works well, easily available, but like the others,
> leaves a film that may be harmful for long term storage.
> Cheers!
> Corey
> Corey Bailey Audio Engineering
> ________________________________
>   From: Jeff Brown <[log in to unmask]>
> To: [log in to unmask]
> Sent: Tuesday, October 9, 2012 10:13 AM
> Subject: Re: [ARSCLIST] Source for D5 - decamethylcyclopentasiloxane
> What are the advantages/disadvantages of working with D5 versus
> working with an isopropyl alcohol drip like Marie O'Connell did?
> Jeff
> At 10:42 AM 10/9/2012, you wrote:
>> After much research I found a reasonable source for D5 here in
>> Canada and they will ship to the U.S.A.
>> You may find the info at the top of my blog page at the moment.
>> or go directly there
>> I know I have been discussing this off-list with a few of you.
>> There is also another blog post a couple of articles down about it
>> working very well with Sony PR-150 on a Sony APR-5003 recorder with
>> a simplified applicator using an envelope moistener found at many
>> major stationary suppliers.
>> And, for something completely different, I have updated my article
>> about my personal image scanning work, celebrating the completion of
>> the bulk of it.
>> but all three of these are currently the top three articles on the
>> blog (on my blog they sort by last-edited date so updated articles
>> are recycled on the main page).
>> Cheers,
>> Richard
>> --
>> Richard L. Hess                   email: [log in to unmask]
>> Aurora, Ontario, Canada           (905) 713 6733     1-877-TAPE-FIX
>> Quality tape transfers -- even from hard-to-play tapes.
>> -----
>> No virus found in this message.
>> Checked by AVG -
>> Version: 10.0.1427 / Virus Database: 2441/5317 - Release Date: 10/08/12

Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada           (905) 713 6733     1-877-TAPE-FIX
Quality tape transfers -- even from hard-to-play tapes.