PT06 Organic, Metallic, Organometallic Pollutants
Exhibit Hall
8:00 AM - Tuesday
(PT083) Aquatic ecotoxicity of mono- and di-organotin stabilizers to freshwater organisms.
Phipps, T.1, Currie, S.1, Farr, C.2, Murphy, S.2, Costlow, R.3, Thomson, M.4, 1 Parametrix, Bellevue, WA, USA2 ATOFINA Chemicals, Inc., Philadelphia, PA, USA3 Rohm and Haas Co., Spring House, PA, USA4 Crompton Corp., Middlebury, CT, USA
ABSTRACT- In 1998, the USEPA launched the HPV Challenge Program, which called for chemical manufacturers to voluntarily commit to provide basic screening-level hazard data for high production volume (HPV) chemicals they manufacture. The organotin industry, through the Stabilizer Task Force of the Organotin Environmental Programme Association (ORTEP), volunteered 27 organotin and related inorganic compounds for this program. The mono- and di-organotin stabilizers — methyltin tris(2-ethyhexylmercaptoacetate) (2-EHMA), dimethyltin bis(2-EHMA), butyltin tris(2-EHMA), dibutyltin bis(2-EHMA), octyltin tris(2-EHMA), and dioctyltin bis(2-EHMA) — are used in PVC applications where high thermostability is required. Some tin stabilizers also are used in food contact applications and potable water pipe. Tin stabilizers are sparingly soluble in water due to their strong hydrophobic character, and limited ecotoxicity data based on standard tests of these tin stabilizers exist. Ecotoxicity studies were conducted using the Water Accommodated Fraction (WAF), Water Soluble Fraction (WSF), or filtered saturated solutions. The toxicity of these compounds to a fish (Brachydanio rerio), an invertebrate (Daphnia magna), and an alga (Scendesmus subspicatus) was tested following 96-h, 21-d, and 72-h exposures, respectively. Studies were conducted using standard OECD test guidelines. The results indicate that under standard test conditions, the tin stabilizers are not acutely toxicity to B. rerio, and there was little or no reduction in algal growth. Preliminary results of 21-day D. magna reproduction studies indicate reduced reproduction at concentrations below the 100% of the WAF. Final D. magna reproduction data will be presented. Based on the current results, there appears to be a low potential for acute environmental effects from tin stabilizers.
Key words: stabilizers, organotins, toxicity, HPV