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| Posted on 4/23/08 at 09:51 AM | |
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Ok. This may be a bit long...but bear with me. I'm not a chemist, but after being in several thousand plants and pretty much printing everything, I have had...since about 1994, severe allergies to a range of things you cannot imagine. Some that have put me in the hospital. Again, I am not a chemist. I expect you to research for yourself, everything I might write here. I know enough to be dangerous thats all. Some things I can tell you about these chemicals. First...you need to identify whats what and why they are concerned and connected. This issue with Bisphenol A is not a new issue. The first study for the exposure limits for Bisphenol A were first done in 1998. The first studies done on Bisphenol A as a chemical that would work like...and/or replace in certain chemical reactions ....Estrogens....was 1930. Bisphenol is not really the total focus of what we as printers should worry about. It is important...but you have other related chemicals all around you. Here is the gist: You have among all of our toys: Phenol...phenyl... Bisphenol-A and paraphenylenediamene (also called 1,4-diamenobenzene, 1,4-phenylenediamene or just PPD)....among others. They all have one key element in common......phenyl. Phenol....notice the "O"...not the "Y" (also known as carbolic acid) is actually what is known in chemistry as the "benzene" ring group. Its usually used as a molecular bonding agent used in aromatic hydrocarbons....to form polymers. Its is generally synthesized from Phenyl (notcie the "Y"  ...which is made from benzene.Phneyl is directly used in styrene as a molecular bonding agent. Where is all of this used? Well...phenol for instance can be used in everything from drugs to antiseptics in its compounded form of phenol. For us old timers..remember the green bottles of hand disinfecting soap that they used at the doctors...called Physo-hex (sp)? That used a variant of Phenol called hexochlorophene as a serious anti-bacterial. High usage eventually led to skin sensitization (dermatitis)...so they dropped the phenol and renamed it Physo-derm...which you can now buy at the drug store. Bisphenol-A (the one in the news right now) has lots of chemical variation names...but can really be thought of as..."Bi-phenol". It has two "benzene rings" in its molecule. It is used in plastics or POLYMERS (very important distinction even though all plastics ARE polymers)..as a molecular bonding agent and the extra benzene ring helps to faster polymerize some of the more difficult newer plastics. This extra benzene ring makes for some instability and leftover phenyl that can leach out....under certain cirumstances and only in certain plastics Ok...there are Seven (7) different categories of plastic.....that you will see in the little recycling triangle symbols on containers. here is what they are and what they have (Bisphenol-A wise) For easier typing...Bisphenol-A will be called "BPA" Symbol #: (1) PET (polyethylene Terepthhalate plastic). It uses no "BPA" as a plasticizer. But has pthhalates...remember that. (2) HDPE (high density polyethylene)...uses no BPA (3) PVC (polyvinylchloride...or vinyl). BPA is used in vinyl as a plasticizer, which means there is a lot of free active BPA. Some of this "MAY" affect you on skin contact, but since BPA generally starts to become unstable with heat and shed its spare benzene ring....the curing process of vinyls and vinyl based inks may actually be the suspect part of exposure. Remember that for later. (4)LDPE (low density polyethylene) Has no BPA (5) Polypropylene has no BPA (6) Polystyrene ...has no BPA...but again has pthhalates. Now we come to the last and maligned class ...7 (7) This is a conglomerate category. It comprises epoxies and PC (polycarbonate)as well a some reground or recycled versions of it. Since BPA...with its extra benzene ring become unstable with low to high acids (like say fruit juice or vinegar) or heat, these plastics shed phenols or phenyl about 50 times faster than all of the others...except possibly vinyls that have not been through a heating process yet to release the extra phenol from the BPA. The worry here is that as they found in the 1930's...the phenyl or phenol leaching from BPA....can mimic estrogen in teh body. Itcan cause hormonal reactions, or early on in infants and growing children...defects related to hormonal imbalances. Our last chemical: Paraphenylenediamene...or also known as 1,4-diamenobenzene or... 1,4-phenylenediamine (known as PPD). I repeat this name game...because as you can see....its got that "benzene ring thing"...going on. This compound is an aromatic amine. Epoxies are amines that also include BPA. Amines on their own..even without BPA....have their own toxicity issues. PPD...is in more substances than BPA by far. Like: Black or dark colored dyes Dyed clothing in general Inks of almost every type Laundry soaps Hair dyes Photo chemicals. It is used in one form or another as a color stabilizer. I have a PPD allergy. Once you are sensitized...you have it for life. Everyone has a certain level of PPD in their system at all times from all of the products it is used in. This does not mean that it affects them on a daily basis. They have not reached a high enough PPD level to be "sensitized" to it. For some people (maybe because their PPD levels are already high enough to be close to the edge),... the first time they start working in a print shop...the sheer volume of PPD in ink products and plastic/paper sheet materials ....kicks them over the edge. The first give away sign I usually see...is a rash...that only seems to be....exactly under their clothes ONLY...if they are wearing dyed goods. It is their skin reacting to the PPD in teh dyes. You will see printers working in black T shirts with a rash that is everywhere the shirt is...and nowhere else. The only solution is to either get them out of the shop...or reduce the levels of PPD's in the rest of their outside lives...to bring their total threshhold below that of an allergic reaction. This means...change soaps, hair products and wera light colored non-dyed goods. It usally takes 10-days to three weeks of "clean" living to get rid of the reaction. But...once sensitized....relapse is almost instantaneous when you get back to old habits or get in really PPD rich environments. Other allergy symptoms of PPD are asthma attacks and cold like symptoms. Pthhalates...are another currently disputed chemical. Just suffice it to say that they are present in the plastic types that cause the most problems. Beware of epoxies. I am highly allergic to them. Beware of almost any amine. Ventilate well. The final gist....BPA is the current issue because of one peculiarity (the Estrogen connection). For us grown people....anything with phenyl, phenol, the benzene ring connection or an amine connection can lead to allergy sensitization. In the long term....it wears your immune system down. Sorry for the length...just some thinmgs you should study yourself....and remember that plastisol is mostly vinyl. Ventilate your shop. Ray | ||
 
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