|Substance Group: Fluorescent Brightener FWA-1|
1. Executive Summary
FWA-1 (Disodium 4,4'-bis[(4 anilino-6 morpholino-1,3,5 triazin-2 yl)amino]stilbene-2,2' disulphonate (CAS-No. 16090-02-1)) is a Fluorescent Whitening Agent (FWA) mainly used (more than 90%) in household detergents in concentrations ranging from 0.05 to 0.15%. It is also used to a far lesser extent (less than 10% in total) in textiles and paper. FWA-1 behaves like colorless direct cotton dyes. Its specific molecular structure is responsible for the high affinity to cotton.
1.1 Environmental Risk Assessment
The final fate and environmental risks of FWA-1 was characterized and assessed by an extensive research program of the Swiss Federal Institute of Technology (ETH) and the chemical industry.
It has been shown that FWA-1 (DAS-1) undergoes in aqueous system a rapid isomerization, followed by photodegradation. A mass balance was conducted, on the basis of monitoring data of a field study of lake Greifensee (Switzerland). Over a period of 12 months, 50% photolysis, 25 % each flushing and adsorption could be determined. Photodegradation leads to numerous metabolites that were not identified. However, this mix of break down products was shown to be less toxic in the aquatic compartment than FWA-1.
The environmental exposure assessment expressed as PEC (Predicted Environmental Concentration) was based on monitoring results from 18 Swiss and German rivers as well as from calculations from the HERA exposure scenario. The measured minimum/maximum concentrations in rivers and lakes ranged from 0.03 to 2 ¼g/L.
Acute effect data on aquatic and terrestrial organisms as well as chronic assays from daphnia and algae are available to calculate the PNECs (Predicted No Effect Concentration) for the different environmental compartments.
The Risk Characterization Ratios (RCR) from monitoring data, HERA and available effects data are below 1 and therefore do not indicate a concern to any environmental compartment.
1.2 Human Health Assessment
FWA-1 is designed to produce an optical brightening of the fabric by deposition of the substance to the fiber during laundering. In some instances or in certain geographical areas, clothes are hand-washed with detergents. It is also predictable that food-contact household items such as eating utensils or dishes may be washed in detergents containing FWA-1.
Based on these possible product uses we anticipate possible consumer contact scenarios including direct skin contact with undiluted consumer product by pretreating clothes or by manually washing laundry, indirect skin contact via residual deposits on clothing, inhalation of detergent dust during consumer product handling, and oral ingestion derived either from residues deposited on dishes, from accidental product ingestion, or indirectly from food and drinking water.
Exposure estimates based on the above summarized exposure scenarios indicate the aggregate estimated FWA 1 internal exposure is SED = 0.23 mg/kg bw/day, which accounts for all relevant dermal, oral and inhalation exposures.
The toxicological data show that FWA 1 is not acutely toxic both via the oral and the dermal route. FWA 1 is not eye or skin irritating and was shown not to induce skin contact hypersensitivity in animals and man. Studies in animals and man gave no evidence for phototoxicity or photosensitization. FWA 1 was shown not to be genotoxic in vitro or in vivo and does not induce tumors in rats and hairless mice after life-time oral or dermal treatment. FWA 1 is considered not to cause either reproductive toxicity or developmental or teratogenic effects. The most critical adverse effect identified after repeated long term dosing of FWA 1 to animals was an increase in absolute kidney weights. A systemic NOAEL of 524 mg/kg body weight/day was established.
Comparison of the aggregate consumer exposure estimate of FWA 1 with the overall oral NOAEL results in a Margin of Exposure of MOE total = 2278. This is a large Margin of Exposure and is adequate to cover all uncertainties in the toxicology database and extrapolations.
Based on the extensive database on toxicological endpoints, the low exposure values calculated for all foreseeable uses of FWA 1 and the resulting large Margin of Exposure described above, it can be concluded that use of FWA 1 in household laundry products is safe for the consumers.
From the available data it can be concluded that FWA-1 has no adverse effects to human and environment.