Table 1 ELoC of PFBS (IUPAC name (1,1,2,2,3,3,4,4,4-Nonafluorobutane-1-sulfonic acid) compared to PBT/vPvB substances

Serious effects to human health

 Poses a threat to human health?

PFBS can easily pass through drinking water treatment facilities due to its low adsorption potential. This means that PFBS can enter and not be removed from the drinking water production chain and will pose a threat to human health via a permanent exposure through drinking water. PFBS has shown a high propensity to transfer and enrich in plants due to its high mobility in plant xylem and can, therefore, enter the human food chain. PFBS has been detected in blood samples from citizens from Italy, Sweden and China. In addition, it has been detected in tissue samples from lungs and kidneys from Spanish citizens. The observed probable serious effects for human health and the environment include thyroid hormonal disturbances and reproductive toxicity, and effects on liver, kidney and haematological system, hormonal disturbances and effects on reproduction and effects on expression of hormone receptors

 Irreversible health effects?

Together the threats above lead to a very high potential for irreversible effects

 Delayed health effects?

Long-term, low dose exposure may potentially lead to currently unexpected or even still unknown effects over longer time periods

 Impaired quality of life?

Drinking water quality is compromised and the toxic effects mentioned above will impair quality of life

Serious effects to the environment

 Irreversible exposure?

PFBS has high potential for irreversible exposure. Based on experimental and quantitative structure–activity relationship (QSAR) results, the degradation of PFBS is very low or negligible. Exposures are not expected to decrease upon cessation of releases because of the high persistence of the substance. Degradation of other PFAS precursors constitutes a secondary source of PFBS which results in continued exposure. PFBS is also mobile in the aquatic environment. Thus, the very high persistence, together with low adsorption potential and high mobility, imply a very high potential for increasing environmental concentrations and potential irreversible exposures of wildlife and of humans via the environment

 Irreversible effect?

Based on predicted continuous exposure, there will be an increasing and poorly reversible environmental background concentration which will accumulate in organisms until reaching an equilibrium. The permanent and irreversible exposure to organisms can lead to irreversible effects. Half-lives in the environment exceed half-lives in organisms

 Intergenerational exposure and effect?

PFBS has been found to transfer from mother to offspring in humans, whales and in birds and may disturb development at sensitive life stages and in vulnerable populations. Thus, intergenerational effects can be assumed via a transport with breast milk from mother to child over generations

 Unknown/uncertain spatial scale?

The high potential to cause very long-term exposures means it is difficult to quantify exposures with sufficient certainty. PFBS is very mobile and can spread to other environmental compartments rapidly, confirmed by its environmental distribution. PFBS has been frequently detected in fresh water, snow, ice and surface water close to point source releases and far from point source releases in marine water

 Disparity between point of release and point of effect?

Prior to 2012, the majority of studies on arctic marine biota did not report PFBS above detection limits. However, in these earlier studies it is likely that the analytical detection limits were inferior to those today. Thus, in more recent studies this observation has been reversed showing that PFBS can migrate to areas far from the point of release and cause effects there. Future concentration levels are uncertain

 Unknown/uncertain temporal scale?

The high global transport potential (characteristic travel distance (CTD) = 17,616 km, P_OV = 220 days), is demonstrated by detection of PFBS in samples of surface water, snow, ice, air and marine water from remote areas such as the Arctic and the Antarctic

 Uncertain/difficult to predict long term fate and toxic effects?

Long-term, low dose exposure may potentially lead to currently unexpected or even still unknown effects

 Harmful to the aquatic environment?

PFBS has been detected in marine (arctic and non-arctic) and freshwater biota throughout the world. PFBS meets the ecotoxicity threshold for the T criterion in Annex XIII of REACH (see above)

 Potential to reach remote pristine areas?

PFBS has a high global transport potential and is already globally distributed (oceans, soil, biota) including in remote pristine areas (arctic, Antarctic). PFBS has been reported in atmospheric samples at trace levels throughout the world, though mostly in rain. The tendency for PFBS to prefer water to air (based on the K_aw value), means that air emissions are likely prone to wet deposition by partitioning with clouds and rain droplets. This serves as a mechanism for transport from one area to another

Other effects

 Increased societal costs?

Short and long term negative effects on human health present costs for society. The cost of breaking the C-F bond in PFBS is high and requires a lot of energy. There are few technically feasible methods for the remediation of PFBS contaminated water. Drinking water analysed for PFBS in areas near and far removed from PFAS source zones report the ubiquitous presence of PFBS. The effects on human health above also result in an increased societal cost, for example through increased healthcare demands. These factors combined pose a high societal cost, currently estimated to be 100 s of millions of Euros for PFAS contaminated soil across Europe [44]

 Negative effect on resources?

There are very few methods that can be used to treat water on the larger scale. PFBS accumulates in the food chain. These factors demonstrate negative effects on resources

 Do emissions need to be minimized?

The consequences of an underestimation of adverse effects are not easily reversible by regulatory action. Even if there is immediate regulatory action to prevent further emission, the adverse effect will continue. Regulatory action can eliminate point source emissions, but they have no influence on what has already been emitted. Environmental redistribution will continue for decades and background levels will keep increasing