Bibra Toxicology Advice and Consulting | Toxicology News: WHO reviews…

Toxicology and Regulatory News in September covers reviews on PFAs chemicals, sensitisation testing methods, as well as safety and consumption recommendations for iodine and toluene.

In this month’s update:

WHO review on per- and polyfluoroalkyl substances (PFAS chemicals)

PFAS have become a global public health concern due to widespread human exposure, including through drinking water and food. The WHO conducted a landscape review of PFAS occurrence and associated health effects to identify priority PFAS and health effect categories for further assessment. The review compiled data on 66 PFAS from health-effect observations and 77 PFAS from occurrence observations, identifying 18 PFAS and six health effect categories for further evaluation to support the development of health-based values.

Reference: WHO

OECD review of respiratory sensitisation testing methods

The OECD reviewed the available methods for assessing the respiratory sensitisation potential of chemicals. The document provides an overview of the regulatory context, mechanisms of action and pathways, a list of about 25 reference chemicals (including isocyanates), and existing in silico, in vitro, ex vivo, and in vivo testing methods. As there are currently no standardised tests for respiratory sensitisation, the review aims to support the development and validation of reliable non-animal testing methods and identifies areas for further research.

Reference: OECD

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ECHA evaluates occupational limit values for toluene

In its draft evaluation of toluene, ECHA derived a candidate 8-hour Time-Weighted-Average (TWA) Occupational Exposure Limit (OEL) of 77 mg/m3, based on a No-Observed-Adverse-Effect Concentration (NOAEC) of 165 mg/m3 for colour vision impairment in occupationally-exposed individuals. A Short-Term (15-minute) Exposure Limit (STEL) of 383 mg/m3 was proposed on the basis that, at this level, transient neurobehavioral effects and respiratory and eye irritation are expected in humans after about 25 minutes of exposure.

Reference: ECHA

EFSA assessment of trifluoroacetic acid

In reassessing the health risks of trifluoroacetic acid (TFA) at the request of the European Commission, EFSA concluded that TFA and its sodium salt are unlikely to be genotoxic. Taking reduced thyroxine (T4) levels observed in an extended one-generation reproductive toxicity study in rats as the most sensitive effect, EFSA derived a benchmark dose lower confidence limit (BMDL20) of 8.6 mg/kg bw/day. This value was used to establish a new ADI of 0.014 mg/kg bw (previously 0.05 mg/kg bw) and an ARfD of 0.07 mg/kg bw.

References: EFSA

BfR and algae iodine content

Certain species of algae, for example seaweeds, are used in food, particularly in Asian countries such as Japan, Korea and China, and consumption is increasing in Europe. Algae can contain high levels of iodine, which can induce toxicity, particularly in vulnerable groups such as pregnant and breastfeeding women, and individuals with thyroid disorders or impaired kidney function.

BfR has recently concluded that limiting iodine levels to 1 g/kg of dry algae could protect against acute effects. They also recommended:

labelling ready-to-eat algae and algae-containing products with their iodine content
consumption recommendations
additional warnings to protect sensitive individuals

Reference: BfR

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