OK, on the whole, your attachment is pretty fair and covers a lot of the problem with nPB. However, there is one grave error in it. It states the ACGIH is an official level. This is not so, it is a recommendation by an NGO, although one that should be taken seriously. Only OSHA PEL's have the force of regulatory status in the USA and, as far as I know, OSHA have not made any regulation regarding nPB. A very early warning is contained in Sclar 1999: Encephalomyeloradiculoneuropathy following exposure to an industrial solvent, G. Sclar, Clin Neurol Neurosurg 101:199-202 (1999) and describes the case of a youth who virtually lost the use of his right arm after exposure to nPB. It is speculated that the protective gloves he was using did not offer sufficient protection and the transdermal uptake was sufficient to cause severe neuropathic conditions in the hand and arm. This was the first reported human neuropathy. Other cases have since been reported, including one where nPB was used as the solvent in adhesives used to make aircraft seats. The workers were exposed to massive vapour levels, peaking at >300 ppm, and several of them had sequelae. I was mandated by a company using nPB for cleaning PCB assemblies. Their equipment was well designed and the background levels were down to the extremely low 3 ppm in the workshop. However, the inspection/retouch operators complained of headaches after the switch from CFC-113 to nPB. It was speculated that, although the background level was low and the assemblies were vacuum dried, there was sufficient nPB vapour trapped in and under the components, especially wound coils, close to the operator's faces, to cause problems. I was co-chair of the UNEP Technical and Economic Assessment Panel nPB Working Group and I made a presentation to the Parties to the Montreal Protocol and my concluding remarks were: "With our current knowledge, the prudent course is to use the precautionary principle: - Do not use nPB where a better-known, non-OD, solvent will work - If it must be used, reduce emissions to the absolute minimum and ensure minimum operator exposure. - Err on the safe side" Of course, this was based more on the fact that nPB is ozone-depleting, rather than toxic. My 2003 report to the Parties concluded: "1.10 Conclusions i. The forecast global expansion of the nPB market has not yet occurred, because of the unclear regulatory situation, the current economic position and geopolitical tensions. ii. The bulk price of nPB, both raw and blended, has dropped to a level more acceptable for general degreasing operations. iii. The global production capacity of molecular nPB and blended solvents has expanded considerably and can meet foreseeable immediate demands once the regulatory and economic barriers are removed. Bromine production capacity is sufficient that more nPB can be produced at fairly short notice, if needed. iv. nPB manufacturers and blenders are heavily promoting their products as replacements for non-ozone-depleting chlorinated solvents, exploiting possible regulatory loopholes. v. The pharmaceutical, agrochemical and speciality chemical industries consume about 5,000 tonnes of nPB annually. The emissions from these are unknown. vi. There is very evident increased interest in the use of nPB in Article 5(1) countries, notably in the Peoples’ Republic of China. vii. Although there is no new information about the reproductive toxicity and neurotoxicity of nPB, there are grounds for grave concern with the incomplete toxicity or epidemiological information already available. viii. Recommended safety practices regarding the use of nPB are not always being observed, resulting in excessive emissions and potential over-exposure of operators. In particular, more attention must be paid to the risks of dermal uptake, which may be more rapid in humans than was thought. ix. In view of the still-unknown toxicology, epidemiology and risk to the ozone layer, Parties are urged to adopt the precautionary principle and to discourage use of nPB in solvents applications, except where it can be shown that no non-ozone-depleting solvent or process is suitable and provided that every measure is taken to protect the operators from any risk of undue exposure and to minimise emissions." Personally, I believe the ACGIH recommendation of a 10 ppm time-weighted exposure level probably presents little risk to operators, although the French ATOFIN recommendation of 5 ppm would be better. I discount the (proposed or promulgated?) Californian regulation of 1 ppm as being too restrictive and unnecessary. However, can 10 ppm be easily maintained? In very expensive and properly maintained/operated zero-emissions machines, probably. I measured 15 ppm round such a machine in China, but it had a minute leak. I measured 200 ppm round another similar machine in Egypt, but the operator removed the cleaned goods before the vacuum extraction had finished its work. I doubt whether it is possible in any open-top vapour degreaser, even with deep refrigerated freeboards. It may just be possible if the assemblies are kept in the freeboard of a very modern machine for at least 30-60 minutes but this cannot be guaranteed and is hardly conducive to a good throughput. BTW, I'm not liked in your country because the Dead Sea Bromine Corp is one of the major producers of nPB and my recommendations have been largely negative!!! Finally, I have a web page on the matter at http://www.cypenv.org/worldenv/files/npb.htm Brian Gabriela Bogdan wrote: > Thank you Brian. > I found several materials on the internet, some contradicting each > other, but this one frightened me. > See attachment. > Gaby > ----- Original Message ----- From: "Brian Ellis" <[log in to unmask]> > To: <[log in to unmask]> > Sent: Friday, December 14, 2007 7:05 PM > Subject: Re: [TN] ABZOLV > > >> The main component is n-propyl bromide. It depletes the ozone layer >> and there is evidence of reproductive toxicity and neurotoxicity. >> Because of the toxicity, various suppliers recommend operator exposure >> levels varying from 5 to 100 ppm. I could provide references tomorrow, >> if required. >> >> Brian >> >> Gabriela Bogdan wrote: >>> Is anybody cleaning assemblies with ABZOLV? >>> Do you know what the health hazards are? >>> Gaby >>> >>> --------------------------------------------------- >>> Technet Mail List provided as a service by IPC using LISTSERV 15.0 >>> To unsubscribe, send a message to [log in to unmask] with following >>> text in >>> the BODY (NOT the subject field): SIGNOFF Technet >>> To temporarily halt or (re-start) delivery of Technet send e-mail to >>> [log in to unmask]: SET Technet NOMAIL or (MAIL) >>> To receive ONE mailing per day of all the posts: send e-mail to >>> [log in to unmask]: SET Technet Digest >>> Search the archives of previous posts at: >>> http://listserv.ipc.org/archives >>> Please visit IPC web site >>> http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional >>> information, or contact Keach Sasamori at [log in to unmask] or >>> 847-615-7100 ext.2815 >>> ----------------------------------------------------- >>> >> >> --------------------------------------------------- >> Technet Mail List provided as a service by IPC using LISTSERV 15.0 >> To unsubscribe, send a message to [log in to unmask] with following text in >> the BODY (NOT the subject field): SIGNOFF Technet >> To temporarily halt or (re-start) delivery of Technet send e-mail to >> [log in to unmask]: SET Technet NOMAIL or (MAIL) >> To receive ONE mailing per day of all the posts: send e-mail to >> [log in to unmask]: SET Technet Digest >> Search the archives of previous posts at: >> http://listserv.ipc.org/archives >> Please visit IPC web site >> http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional >> information, or contact Keach Sasamori at [log in to unmask] or >> 847-615-7100 ext.2815 >> ----------------------------------------------------- >> --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------