Rabbits Were Killed

I found a bottle of Expo-brand white board cleaner on the table outside my office, and I was curious to know what was in it, so I Googled “expo whiteboard care msds” and ended up at this list of Material Safety Data Sheets, one of which was for Expo Cleaner in Bottles.

This MSDS lists the composition of the white board cleaner as a 0.1% to 2% concentration of 3-butoxypropan-2-ol, another search for which leads me to another MSDS for this ingredient alone, under the brand name “Dowanol PnB,” from Dow Chemical. It’s described there as follows:

DOWANOL^TM PnB glycol ether is a fast-evaporating, hydrophobic glycol ether with high solvency and excellent coupling abilities. DOWANOL^TM PnB glycol ether is extensively used in heavy-duty cleaning formulations. It does an excellent job of solvating and coupling hydrophobic greases and oils in household as well as industrial formulations. It is partly water soluble and miscible with most organic solvents. DOWANOL^TM PnB glycol ether also provides excellent surface-tension lowering ability. In coatings DOWANOL^TM PnB offers good coalescing ability in systems requiring fast evaporation.

If you’re curious, here’s what the molecule looks like.

But back to the rabbits.

Here’s Section 11, Toxicological Information, from the Expo Cleaner in Bottles information:

I was just quickly breezing through the details on the sheet when the word “Rabbit” jumped out at me.

“Rabbit?”, I wondered to myself. What does this have to do with rabbits?

Some more Googling led me to the Canadian Centre for Occupational Health and Safety page about LD50, which defined the term thus:

LD stands for “Lethal Dose”. LD50 is the amount of a material, given all at once, which causes the death of 50% (one half) of a group of test animals. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material.

Toxicologists can use many kinds of animals but most often testing is done with rats and mice. It is usually expressed as the amount of chemical administered (e.g., milligrams) per 100 grams (for smaller animals) or per kilogram (for bigger test subjects) of the body weight of the test animal. The LD50 can be found for any route of entry or administration but dermal (applied to the skin) and oral (given by mouth) administration methods are the most common.

So if I’m reading this correctly, 50% of rabbits that were given a dermal 3100 mg/kg dose of 3-butoxypropan-2-ol died as a result.

The heart of the popular opposition to animal testing has focused on cosmetics; indeed the Body Shop page on the issue is headed by adorable-looking rabbits. I don’t know if I’ve ever come across office products, like white board cleaner, that make animal testing claims; it had never occurred to me that the cousins–or at least half of the cousins–of the Body Shop’s rabbits were killed to allow me to feel safe cleaning my white boards.

I’d like to know more about this.