Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Biosolids Samples for 

D4

August 16, 2013

Silicones Environmental, Health and Safety Center 1

Synopsis: 

This testing standard provides guidelines for the collection and analysis of environmental samples for D4

in support of a Testing Program detailed in this Enforceable Consent Agreement (ECA). The purpose of 

the Testing Program is to “...develop environmental testing data for D4 in the vicinity of manufacturing 

and processing (including product formulating) sites and POTWs in the U.S. so that exposures and risks 

to sediment and aquatic organisms can be assessed.” An additional requirement of the ECA is to sample 

and analyze biosolids from each POTW. 

This standard cites the requirements for the sampling of biosolids as described in Section VII of the ECA 

and Appendices 2 and 3 and identifies specific guidelines and references that will be used in the 

preparation of site-specific Sampling Plans for the collection and analysis of biosolids samples, which will 

be included in a Study Plan for the Testing Program. 

Requirements for sampling biosolids:

Per Appendix 2, Environmental Testing for Indirect Discharge Sites and Appendix 3, POTWs Not 

Receiving D4 from Industrial Facilities: 

“Biosolids samples will be collected as close to the release point of the treatment facility as possible 

and the concentration of D4 in the biosolid samples will be measured.”

Establishment of the location for biosolids sample collection: 

At each POTW, biosolids samples shall be collected as close as possible to the biosolids release point as 

possible. To satisfy this requirement, detailed knowledge of each facility’s handling of biosolids is 

required. The chosen location for sampling should be where the biosolids are prepared, staged, or 

stored for transportation off site. The exact location of the point of release should be established during 

preparation of the site-specific Sampling Plans. 

Special considerations for the sampling and handling of biosolids samples for D4: 

Cyclic volatile methyl siloxane (cVMS) materials, such as D4, are widely used in consumer products and 

may be present in personal care products, commercial products, and lubricants, and may be 

components of antifoams widely used in waste water treatment plants. To avoid the potential for 

sample contamination during collection, processing, storage, and analysis for D4 in environmental 

matrices, appropriate quality control measures should be implemented to the extent possible in the 
Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Biosolids Samples for 

D4

August 16, 2013

Silicones Environmental, Health and Safety Center 2

field. For example, field crew shall refrain from using any personal care products (e.g. , sun-block, sunscreen, hand lotion, antiperspirants, etc.) while preparing for or conducting any field activities to 

minimize the possibility for contamination with cVMS materials. Appropriate requirements for collecting 

and handling biosolids samples that comply with the special considerations related to D4 shall be 

specified in the site-specific Sampling Plan. 

Collection of biosolids samples for analysis of D4: 

On the day of sampling at each POTW, two (n=2) composited biosolids samples shall be collected at the 

established location. The sample collection procedure will be based, as appropriate, on USEPA (1989, 

Section 2.2 Sample Point Selection and Section 2.3 Sample Collection) (see Annex 1). Once composited 

biosolids samples are collected, they will be processed in preparation for sending to an analytical 

laboratory following general procedures similar to those used for sediments as given in Powell and 

Woodburn (2009) (Sample Collection section, p. 9, Analysis of Cyclic Volatile Methylsiloxane (cVMS) 

Materials section, Extraction of Surface Sediments sub-section, p. 12, and Quality Control, p. 14) (see 

Annex 2). Sample collection methods as well as specific requirements for sample container preparation, 

sample handling, sample preservation, shipping and storage of the samples will be detailed in the sitespecific Sampling Plans. 

During each sampling event at a given site, two field blanks will be prepared as described in Powell and 

Woodburn (2009). Serving as field blanks for biosolids collection and handling, two reference sediment 

samples having very low or non-detectable concentrations of cVMS materials shall be taken into the 

field and processed like a biosolids sample. The reference sediment samples will be used to evaluate 

contamination bias resulting from collection, processing, transport, storage, and analysis of samples.

Specific requirements for preparation, processing, and analysis of field blanks shall be detailed in the 

Study Plan and the Quality Assurance Project Plan (QAPP).

Following collection of biosolids samples, subsamples shall be separately prepared from the composited 

samples for analysis of carbon and water content following procedures equivalent to those used for 

sediments as given in Powell and Woodburn (2009) Characterization of Sediments, p. 10 (see Annex 2). 

The biosolids samples should be analyzed by carbon coulometry or an equivalent method for total 

carbon, total inorganic carbon, and total organic carbon, and loss-on-ignition for total water content and 

total organic matter content.

Analysis of Biosolids Samples for D4: 

All biosolids samples shall be analyzed for D4 at a commercial testing laboratory. The commercial 

laboratory will validate a method for the analysis of D4 in the biosolids samples that shall be adapted 

from the analytical method specified in Knoerr (2012) (see Annex 3). The specific level of detection shall 
Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Biosolids Samples for 

D4

August 16, 2013

Silicones Environmental, Health and Safety Center 3

be based on the Practical Quantitation Limit (PQL) (USEPA 1985 and APHA 1999, Part 1030C, see 

Annexes 4 and 5). The PQL is in turn based on the matrix-specific Method Detection Limit (MDL). These 

terms are defined as follows:

Practical Quantitation Limit (PQL): Minimum concentration of a constituent in a sample that can be 

measured among laboratories within specified limits during routine laboratory operations. The PQL 

is proposed because different laboratories may produce different MDLs even though they may be 

using the same analytical procedures, instruments and sample matrices. The PQL is typically defined 

as 5 to 10 times the MDL.

Method Detection Limit (MDL): Concentration of a constituent in a sample, that when processed 

through the complete analytical method, can be measured and reported with 99% probability that it 

is greater than 0 or statistically different from a blank. The MDL is a measure of a methods ability to 

quantify a constituent in a sample matrix.

During method development, the Knoerr (2012) analytical method for D4 did not determine a matrixspecific Method Detection Limit (MDL). However, since the analytical method (Knoerr 2012, Annex 2) is 

very similar to that of sediment (Powell and Woodburn 2009, see Annex 3), the sediment MDL of 8.5 

ng/g (wet weight, ww) will be the basis of the biosolids PQL. For use at a commercial laboratory, the 

targeted PQL for D4 in biosolids shall be calculated as 5 times the Powell and Woodburn (2009) MDL for 

sediment. Therefore, when rounded to one significant figure, the PQL for D4 in biosolids shall be 40 

ng/g, ww.

Compliance with Good Laboratory Practices:

Sample collection, handling, and transfer activities should be conducted in accordance with GLP 

requirements, as applicable. The analytical laboratory conducting the analyses of D4 shall be a GLP 

certified facility and all analytical work shall be conducted in accordance with GLP requirements. The 

QAPP shall be prepared according to USEPA guidance and shall include information on all field and 

laboratory quality control measures to be followed. 

Annex 1 – USEPA (1989): POTW Sludge Sampling and Analysis Guidance Document, Section 2.2 Sample 

Point Selection and Section 2.3 Sample Collection. EPA 833-B-89-100, August, 1989. 

Annex 2 – Powell DE, Woodburn KB. 2009. Trophic Dilution of Cyclic Volatile Methylsiloxane (cVMS) 

Materials in a Temperate Freshwater Lake. Dow Corning Corporation, HES Study No. 10771-108.

Annex 3 – Knoerr SM. 2012. Non-Regulated Study: Development of a Method for the Collection, Storage 

and Analysis of Biosolids Obtained from a Waste Water Treatment Plant for the Quantitation of 

Octamethylcyclotetrasiloxane. Dow Corning Corporation Study Number 11800-108. 
Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Biosolids Samples for 

D4

August 16, 2013

Silicones Environmental, Health and Safety Center 4

Annex 4 – USEPA 1985. National primary water drinking standards: synthetic organics, inorganics, and 

bacteriologicals. 40 CFR Part 141; Federal Register 50: No. 219, November 13. 1985.

Annex 5 – APHA 1999. Standard Methods for the Examination of Water and Wastewater, Part 1030 C. 

Method Detection Level, Section 2 Determining Detection Levels. American Public Health Association, 

American Water Works Association, Water Environment Federation.