I did not want to hijack the thread that I saw this advice in

[nightrainfalls]

Btw we saw a study somewhere(forget atm) about how the ink on newapaper, because there is always some excess inks, and in general can be known to cause health problems after a while in reptiles and amphibians. Anyone else hear about, know, or experience anything?

Dear Chris,

You bring up and interesting point. I use newspaper as mulch in my vegetable garden, and in my reptile enclosures. I have checked into the possibility that newspaper mulch is toxic, both to myself and my pets. I am providing the following information regarding the background on the types of inks used in newspaper, industry recommendations for use of newspaper in agriculture and livestock husbandry, and studies on ink toxicity. First, let me say that in the past newspaper ink was mildly toxic. In the past it has contained lead, and cadmium. Currently, at least in the United States, lead based inks are not permitted and the majority of black newsprint uses some mixture of a highly refined carbon black and mineral oil or vegetable based soy carriers along with certain trace inorganic pigments. Since newspaper is a massive source of waste, the EPA actually keeps tight controls on the toxicity of the newspaper ink. You can read more about the materials used in newspaper inks at the following sources. http://www.usink.com/acrobat/whatisink.pdf The Chicago Tribune actually makes explicit statements about the safety of using its papers as compost http://articles.chicagotribune.com/2...nk-soybean-oil Ohio State University has done considerable research in this field and found

One major concern for livestock producers and consumers is the safety of livestock bedded on newspaper containing inks. Until 10 years ago, lead, cadmium and other toxic heavy metals were commonly used in paper inks.
Now, however, most publishers use organic pigments. Most of these pigments are the same as those used in tattoos, lipstick, hair coloring and other cosmetics.
You may have seen the "soy ink" symbol on a newspaper, which tells the reader that the newspaper company is using soy based inks for printing. Soy inks are derived from soybeans, one of Ohio's largest cash crops.
A Pennsylvania State University study of beef steers bedded on newspaper for 140 days revealed no detectable traces of heavy metals in the blood or liver tissues of the animals. It was noted that the paper used was primarily "black on-white" newsprint and contained a very limited amount of colored inks. Cornell University researchers fed pelletized newspaper at rates of up to 10 percent of the total diet to dairy cows and found no significant risk to human or bovine health.
The newspaper industry has made great efforts to generate a non-toxic waste stream. Printed matter from advertising inserts, catalogs and magazines, however, is not subject to the same voluntary controls of ink quality. Unregulated paper products for bedding of animals that provide meat and milk should be used with caution. http://ohioline.osu.edu/cd-fact/0136.html

Unfortunately, for economic reasons, studies have not been carried out on pythons and potential for toxicity, but they have been carried out for many other animals, including most forms of livestock. Studies on live stock have looked for increases in toxins in meat and milk. Obviously if toxins leached out of newspaper bedding, or were absorbed after bedding was ingested, it could not be used for human food production. These studies have found that black newsprint paper does not significantly increase toxin levels in any animal studied. http://www.wvu.edu/~agexten/pubnwsltr/TRIM/10852.pdf

Here is a discussion of ink toxicity it humans:

There are three ways ink can have contact with the human body. There is dermal absorption (through the skin), inhalation of ink particles into the respiratory tract (breathing), or ingestion through the mouth and into the digestive system (eating).
There is little threat of dermal absorption of ink or its ingredients once the ink is dry because the ink has achieved its stable state. The ingredients that were potentially absorbable become dry and are no longer able to be absorbed. Lead, which can be absorbed through the skin, was banned as an ingredient in ink by the EPA in 1985 and is, therefore, no longer a threat. Stall trials concluded that the ink rub-off from printed newsprint was not a concern for animals.
Inhalation is a concern only when the ink is in liquid form either in transportation or at the place of production. Particle droplets and evaporation of active ingredients are a concern because they can be inhaled if proper prevention techniques are not practiced during the printing of the newspapers. Again, however, once the ink is applied to the paper and dried, it is stable and there is little danger of inhaling ink particulates. There is a threat of inhalation of dust from finely shredded paper. In this case, the concern is over fibrous inhalation rather than the toxicity. To avoid fibrous inhalation, stall trial results suggest using shreds at least 1 inch x 1 1/2 inch or larger.
Ingestion of inks used on newsprint has not been an issue because the ingredients used in the inks are not considered toxic in either the liquid or dry state. The only animal that showed an indication of grazing on the newspaper bedding was the horse and the grazing was in limited amounts. No other animals indicated any interest in the newsprint as a food source.
These trials and ink references are for the black inks used in newsprint. The trials do not include the waxed or glossy inserts or supplements that accompany newspapers, nor does it include colored inks used on those publications. http://ohioline.osu.edu/cd-fact/0122.html Please note, this summary contains references for the actual studies mentioned in several other summaries.

There is some conflicting data on ink toxicity, which to be fair, I must present. The following study was designed to explore the occupational dangerous of dealing with printers inks. The ingredient in black ink, carbon black, when extracted with benzene has been shown to be carcinogenic, though carbon black itself is not carcinogenic. Furthermore, mineral oils which are currently being displaced by other alternatives have been shown to be skin irritants when applied directly to skin in liquid form. The study detailing these findings and the background of these finding is https://ntp.niehs.nih.gov/ntp/htdocs/st_rpts/tox017.pdf . The study is excellent, but applies more to long term liquid exposure to actual ink, not to ink absorbed in paper. Mineral oil that is not well refined can also contain trace carcinogenic impurities. Studies differ on whether carbon black is mutagenic depending on the presence of nitropyrenes. The study involved cutaneous application of ink directly to the skin of mice and rats for 13 weeks. Local skin irritation was found, and female rats had a statistically significant but small loss in weight compared to controls. The amounts of ink these animals were exposed to were artificially high, because the study was designed to evaluate occupational risks of using inks in printing rooms. It should be noted that dried carbon black would not contain benzene, since benzene is an aromatic compound that rapidly evaporates. Mineral oil is often used medicinally and purchased for human consumption. http://www.webmd.com/drugs/2/drug-15...e-oral/details Considering the bulk of the data, it seems likely that newspaper is safe to use as mulch in gardens and as animal bedding. The toxicity of the specific chemicals used is small, and the exposure is very low or non existent.

There is one small area for uncertainty. The safety of this material has never been studied in reptiles. Considering the facts-- the majority of the ink found in newsprint is dried and stable in the fibers of the paper, pythons do not ingest newspaper except by accident, the dangerous materials in ink are likely to evaporate long before the paper is used as substrate, and the relatively impervious nature of snake skin-- it is highly unlikely that newspaper is in any way toxic to pythons. This is probably true of most bedding's.

David