Democrats on the Energy and Commerce Committee are flagging problems with third-party inspections, which many growers and retailers rely on for food safety oversight, and urging federal officials to reform the audit system.

Lawmakers sent a letter to Food and Drug Administration Commissioner Margaret Hamburg Tuesday citing the “significant problems” the panel found during its investigation of the multi-state cantaloupe listeria outbreak, the deadliest foodborne illness outbreak in 100 years.

“We urge you to review closely the information uncovered during our investigation,” read the letter, signed by Ranking Member Henry Waxman, D-CA; Dianna DeGette, D-CO; John Dingell, D-MI; and Frank Pallone, D-NJ.  “In particular, the investigation identified significant problems with the third-party inspection system used by growers and distributors to ensure the safety of fresh produce, This auditing system is often the first and only line of defense against a deadly food borne disease outbreak.”

In their investigation, Committee staff obtained documents from and interviewed “high-ranking officials” at FDA, Jensen Farms, the cantaloupe grower, Primus Labs, the third-party auditor that inspected Jensen right before the outbreak, and Frontera Produce, the distributor that shipped the cantaloupe across the country.

The staff report points out that though FDA officials identified serious problems and design flaws at Jensen Farms, the company was given a “superior” rating by Primus Labs just weeks before the outbreak began to grab national headlines.

“Our investigation reveals some of the reasons why: the auditors’ findings were not based on the practices of the best farms and failed to ensure that the producer met FDA guidance; the auditors missed or failed to prioritize important food safety deficiencies; the auditors lacked any regulatory authority and did not report identified problems to the FDA or other state or federal authorities; the auditors did not ensure that identified problems were resolved; and the auditors provided advance notice of site visits and spent only a short period of time on-site. It also became apparent in the investigation that the auditors had multiple conflicts of interest.”

The letter calls for FDA to develop a model program for domestic auditors “that could become the standard of care for third-party auditing programs in the United States.”

Lawmakers also called attention to the inherent conflict of interest issues with third party audits — the company that depends on a passing audit often gets to choose which company conducts the audit, which would contribute to certain company’s “extraordinarily high” pass rate. For Primus Labs, it was 97 percent.

“Indeed, the problems identified in the audits of Jensen Farms are similar to those that the Committee identified in food safety investigations in 2009 and 2010. In 2009, following the Salmonella outbreak in peanut butter products sold by the Peanut Corporation of America (PCA), a Committee investigation revealed that a private, for-profit auditing firm gave the company glowing reviews. The auditor, AlB, was selected by PCA, it was paid by PCA, and it reported to PCA. The auditor awarded a “superior” rating to the company’s plant. Six months after the audit, PCA’s products killed nine people and sickened 691 people.”

AIB also awarded Wright County Egg — the massive farm involved in a half-billion egg recall and Salmonella outbreak in 2010 — a “superior” rating and had awarded the company a “recognition of achievement.” Two months later, FDA reported a much different picture of “serious violations of food safety standards, including barns infested with mice, chicken manure piled eight feet high, and un-caged hens tracking through excrement,” according to the staff report.

“Like it or not our food safety system relies heavily on third-party auditors to identify dangerous practices and prevent contaminated foods from reaching the market,” concludes the letter. “We believe reforms in third-party audits are essential. We call on you to address the problems identified in this investigation in regulation and guidance.”

Read the full letter here.