garden hose

Garden Hose Study Methods

Each hose was cut apart and its components tested separately. The flexible plastic hose was often composed of layers. Some hoses had only one homogeneous layer; others had up to five stacked layers. Before testing, the layers were separated, with Layer 1 representing the exterior, Layer 2 the next layer in, and so on.

A high definition X-ray fluorescence spectrometer (HD XRF) by XOS was used to measure element concentrations, including lead, bromine, chlorine, antimony, and tin, in each component. Chlorine content higher than 10% by mass suggests the presence of PVC plastic.

A Nicolet Fourier Transform Infrared Spectrometer (FTIR) from Thermo Scientific was used to determine polymer type, including PVC. FTIR was also used to detect the presence of plasticizers, particularly in PVC hoses, where phthalates are a concern. Other plasticizers analyzed in hoses were adipates and trimellitates.

Our FTIR plasticizer detection techniques have been validated during the past year for many PVC products by a CPSC-certified, third-party lab using mass spectrometry. Our FTIR limit of detection for phthalates is, conservatively, about 1% by mass in PVC.

In this 2016 study, CPSC-certified lab tested three of the 32 new garden hoses for phthalates and other plasticizers using gas chromatography/mass spectrometry (GC/MS). Their results were consistent with our FTIR findings.

Additionally, seven hoses were selected for a leaching test. Municipal drinking water was held in the hoses for 48 hours, then the water was sent to a certified lab. Six water samples were tested for lead using inductively coupled plasma mass spectrometry (EPA method 6020 with sample preparation method 3005A) and three water samples were tested for phthalates and BPA using gas chromatography/mass spectrometry (EPA method 8270C with sample preparation method 3510C). A “faucet blank” sample containing fresh tap water was also collected and tested for comparison. The faucet blank contained no detectable phthalates, lead, or BPA.