Tetrafluoroboric acid

Endpoint summary

Description of key information

Since it is likely that hydrogen tetrafluoroborate will be absorbed and in the absence of substance-specific absorption data, the default absorption values from the REACH guidance (Chapter 8, R.8.4.2) are used for DNEL derivation, namely: 100% for inhalation, 50% for oral and 50% for dermal absorption.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

50

Absorption rate - dermal (%):

50

Absorption rate - inhalation (%):

100

Additional information

No data is available on the toxicokinetics of hydrogen tetrafluoroborate. Moreover, no in vivo toxicological data is availabe for hydrogen tetrafluoroborate due to the corrosive properties of the substance. Therefore data from the structural analogue potassium tetrefluoroborate has been used to determine the toxicological effects of repeated exposure to hydrogen tetrafluoroborate. An acute inhalation study and sub-acute oral and inhalation toxicity studies in rats are available for potassium tetrefluoroborate. In one of the two oral studies (28-day study according to OECD guideline 407), slight, reversible decreases in red blood cell counts, haematocrit and haemoglobin occurred in females. These systemic changes suggest absorption of the substance by the gastro-intestinal tract. In the other oral study (reproduction/developmental toxicity screening study according to OECD guideline 421) slight decreases in body weight (gain) and food intake occurred at 116.5 and 350 mg/kg bw/day. However, these findings cannot be unequivocally be interpreted as evidence of systemic availability of the substance. The marked growth retardation in male rats dosed with 1000 mg/kg bw/day was accompanied by a marked reduction in food intake, especially during the first few days of treatment, and provides, therefore, no clear evidence of oral absorption either. The other effects observed in this oral study (decreased numbers of pregnant females, corpora lutea and implantation sites; increased number of runts; mortality of dams and pups during lactation) may indicate systemic availability. In the sub-acute inhalation toxicity study, slightly decreased body weight and reduced food intake occurred in male rats of the high concentration group. Though such slight effects are not clear evidence of absorption of the substance upon inhalation, it is likely that the substance will be absorbed if it is inhaled because the oral studies indicate potential for absorption following ingestion.

Since it is likely that no differences exist between the absorption of potassium tetrafluoroborate and hydrogen tetrafluoroborate, and since no substance-specific absorption data is available, the default absorption values from the REACH guidance (Chapter 8, R.8.4.2) are used for DNEL derivation, namely: 100% for inhalation, 50% for oral and 50% for dermal absorption.