Phenol, 4-nonyl-, branched

Toxicity to terrestrial arthropods

Description of key information

No reliable short-term data were available specifically relating to arthropods. However, the key study by Scott-Fordsmand et al., (2004) reported an EC10 based on Folsomia fimetaria reproduction of 23 mg nonylphenol/kg.  This study is reliable with restriction, using the Folsomia genus, an oven-dried soil and is equivalent to an international ISO protocol. Importantly, this is the lowest EC10 in the reliable dataset.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil dwelling arthropods:

23 mg/kg soil dw

Additional information

There were five reliable studies relating to the long-term exposure of arthropods to nonylphenol; no reliable short-term data were available. Two studies met the strict adequacy requirements of the IUCLID Robust Study Summary; these were the Scott-Fordsmand et al., (2004) and the Domeneet al.,(2009) study. The long-term data for Collembola species ranged from 23 to 63.2 mg nonylphenol/kg with test durations ranging from 21 to 64 days.

Three studies provided comparable data forFolsomia fimetariaexposure to nonylphenol for 21 days with EC10 values of 23, 24 and 27 mg nonylphenol/kg, relating to the studies by Scott-Fordsmand and Krogh (2004), Krogh (1996) and Holm (undated, but reported in the nonylphenol EU Risk Assessment Report, 2002). ENVIRON has not been able to review the Krogh (1996) and Holm studies directly but the data from these studies is taken directly from the EURAR (2002) and offered as supporting information here. The study by Widartoet al.,(2007) presented a 64-day NOEC value based on survival onFolsomia candidaof 32 mg nonylphenol/kg. These four studies correspond closely to each other and provide strong evidence that no-effect or EC₁₀levels for Collembola are between 23 and 32 mg/kg.

However, these three studies whilst considered acceptable for REACH purposes were classified as ‘reliable with restrictions’ (Klimisch 2) as the studies were all shorter than the standard duration (28 days) and lacked crucial information, such as the purity of the chemical. The studies considered to provide adequate information for a Robust Study Summary, whilst being reliable, were those by Scott-Fordsmand et al., (2004) and Domeneet al,. 2009. In the Scott-Fordsmand study reported Folsomia fimetaria long-term toxicity EC10 of 23 mg/kg. The Domene et al., (2009) study reported,Folsomia candida, the preferred test species was exposed to nonylphenol in artificial soil for the recommended duration of 28 days. The resulting EC₁₀was 63.2 mg nonylphenol/kg. However, the Scott-Fordsmand et al (2004) study is recommended as the key study as this represents the most sensitive toxicity data and is supported by the evidence of similar or slightly higher toxicity-based NOEC/EC10 values. The study meets the reliability and adequacy requirements of REACH.