1 Human & Environmental Risk Assessment on ingredients of household cleaning products - Version 1 . April 2005. Secondary Alkane Sulfonate (SAS). (CAS 68037-49-0). All rights reserved. No part of this publication may be used, reproduced, copied, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the HERA Substance Team or the involved company. The content of this document has been prepared and reviewed by experts on behalf of HERA with all possible care and from the available scientific information. It is provided for information only. Much of the original underlying data which has helped to develop the risk assessment is in the ownership of individual companies.
2 HERA cannot accept any responsibility or liability and does not provide a warranty for any use or interpretation of the material contained in this publication. 1. Executive Summary General Secondary Alkane Sulfonate (SAS) is an anionic surfactant, also called paraffine Sulfonate . It was synthesized for the first time in 1940 and has been used as surfactant since the 1960ies. SAS is one of the major anionic surfactants used in the market of dishwashing, laundry and cleaning products. The European consumption of SAS in detergent application covered by HERA was about tons/year in 2001. Environment This Environmental Risk Assessment of SAS is based on the methodology of the EU. Technical Guidance Document for Risk Assessment of Chemicals (TGD Exposure Scenario) and the HERA Exposure Scenario.
3 SAS is removed readily in sewage treatment plants (STP) mostly by biodegradation (ca. 83%) and by sorption to sewage sludge (ca. 16%). Only around 1% of the mass load from sewage is discharged into surface water and readily biodegraded in river as well. The Predicted Environmental Concentrations (PECs) for STP, water, sediment and soil were estimated for both scenarios (HERA and TGD). Due to the low volatility of SAS air concentrations are very low and are therefore not considered in this assessment. For the aquatic compartment acute and chronic data for all three trophic levels are available and the PNEC aquatic was calculated from the NOEC reproduction based on a 21d Daphnia study. As no sediment and terrestrial ecotoxicity data are available the equilibrium partitioning method was used to derive a PNEC sediment and PNEC soil.
4 The PNECSTP was derived from a chronic study on bacterial cell growth. The Environmental Risk Characterisation for all compartments (STP, water, sediment and soil) and both scenarios (HERA and TGD) gave PEC/PNEC quotients below 1. From the comparison of the Predicted Environmental Concentrations with measured data it is obvious that the HERA Scenario is more realistic than the TGD Scenario. Indirect exposure of humans via the environment was also taken into account. Based on the calculated local and regional doses in drinking water and food indirect exposure for humans can be neglected. Human Health The presence of SAS in many commonly used household detergents gives rise to a variety of possible consumer contact scenarios including direct and indirect skin contact, inhalation, and oral ingestion derived either from residues deposited on dishes, from accidental product ingestion, or indirectly from drinking water.
5 The consumer aggregate exposure from direct and indirect skin contact as well as from inhalation and from oral route in drinking water and dishware results in an estimated total body burden of g/kg bw/day. The toxicological data show that SAS was not genotoxic in vitro or in vivo, did not induce tumors in rodents after two years daily dosing using both, the oral and dermal route of exposure, and failed to induce either reproductive toxicity or developmental or teratogenic effects. The critical adverse effects identified are of local nature mainly due to the irritating properties of high concentrated SAS. Comparison of the aggregate consumer exposure to SAS with a systemic NOEL of 180. mg/kg body weigh per day (assuming 90% absorption; adapted from Michael, 1968).
6 Which is based on a chronic feeding study, results in an estimated Margin of Exposure (MOE) of 46500. This is a very large Margin of Exposure, large enough to account for the inherent uncertainty and variability of the hazard database and inter species and intra species extrapolations (which are usually conventionally estimated at a factor of 100). Neat SAS is an irritant to skin and eyes in rabbits. The irritation potential of aqueous solutions of SAS depends on concentration. However, well documented human volunteer studies indicate that SAS up to concentrations of 60% active matter is not a significant skin irritant in humans. Local effects of hand wash solutions containing SAS do not cause concern given that SAS is not a contact sensitizer and that the concentrations of SAS in such solutions are well below 1% and therefore not expected to be irritating to eye or skin.
7 Laundry pre-treatment tasks, which may translate into brief hand skin contact with higher concentrations of SAS, may occasionally result in mild irritation easily neutralized by prompt rinsing of the hands in water. Potential irritation of the respiratory tract is not a concern given the very low levels of airborne SAS generated as a consequence of cleaning spray aerosols or laundry powder detergent dust. In view of the extensive database on toxic effects, the low exposure values calculated and the resulting large Margin of Exposure described above, it can be concluded that use of SAS in household laundry and cleaning products raises no safety concerns for the consumers. 2. Contents 1. Executive Summary _____ 2.
8 2. Contents _____ 4. 3. Substance Characterisation _____ 6. CAS No. and Grouping Information _____ 6. Manufacturing Route and Production/Volume Statistics _____ 10. Manufacturing Route _____ 10. Production/Volume statistics _____ 11. Use applications summary _____ 12. 4. Environmental Assessment _____ 13. Environmental Exposure Assessment_____ 13. Environmental Fate _____ 13. Biodegradation in Water _____ 13. Biodegradation in Sediment and Soil _____ 16. Abiotic Degradation in Air _____ 17. Abiotic Degradation in Water, Sediment and Soil_____ 17. Volatilisation _____ 17. Sorption to soil, sediment and sludge _____ 17. Bioconcentration _____ 18. Removal _____ 19. Monitoring studies _____ 21.
9 PEC Calculations _____ 23. Summary of the data used in exposure calculations _____ 23. Aquatic Compartment _____ 25. Sediment Compartment _____ 25. Soil Compartment _____ 25. Sewage Treatment Plant (STP) _____ 26. Secondary Poisoning _____ 26. Indirect Exposure of Humans via Environment_____ 26. Environmental Effects Assessment _____ 27. Ecotoxicity _____ 27. Aquatic Ecotoxicity _____ 27. Sediment and Soil Ecotoxicity_____ 32. PNEC Calculations _____ 33. PNEC water _____ 33. PNEC sediment _____ 33. PNEC soil _____ 33. PNECstp _____ 33. Environmental Risk Characterisation _____ 34. Discussion and Conclusions _____ 35. 5. Human health assessment _____ 36. Consumer exposure _____ 36. Product types _____ 36.
10 Consumer Contact Scenarios _____ 37. Consumer exposure estimates_____ 38. Direct skin contact from hand dishwashing_____ 38. Direct skin contact from hand washed laundry _____ 40. Direct skin contact from laundry tablets _____ 41. Direct skin contact from pre-treatment of clothes _____ 41. Indirect skin contact from wearing clothes _____ 42. Inhalation of aerosols from cleaning sprays _____ 43. Oral Exposures to SAS _____ 44. Accidental or intentional overexposure _____ 45. Hazard assessment_____ 46. Summary of the available toxicological data _____ 46. Acute toxicity _____ 46. Skin Irritation_____ 49. Eye irritation _____ 52. Sensitisation_____ 53. Repeated Dose Toxicity_____ 55. Genetic Toxicity _____ 57.