Shale gas exploration company Cuadrilla has been ordered no to use an information brochure in its present form after a complaint from anti-fracking campaigners Refracktion.

The Advertising Standards Agency (ASA) ruled that some of the company’s claims exaggerated evidence on the safety of hydraulic fracturing, or “fracking”. It ordered Cuadrilla to caveat and qualify some of the language, and that the brochure should not appear again in its current format.

However, 11 of the 18 controversial passages identified in the brochure, sent to households in Lancashire, were deemed to be acceptable.

A spokesman for Refracktion claimed victory. He said: “Cuadrilla make great play of their commitment to a “fact-based conversation” about fracking and have even suggested that the case against fracking has been commandeered by extremists. What we can clearly see here is that the necessary “conversation” is not being distorted by extremists but by Cuadrilla themselves.”

However, Cuadrilla described some of the requirements as “absurd and pedantic” and may appeal the decision, according to the Guardian. In one passage, the firm was banned from saying its “fracturing fluid does not contain hazardous or toxic components”. Although it has only used water, sand and a non-toxic lubricant to date, it could use other substances in future, the ASA said.

Cuadrilla chief executive Francis Egan said he was disappointed the ASA had ruled against seven of the passages, but added “it is important to note the ASA has confirmed that hydraulic fracturing can be done safely”.

Egan said: “We do believe the ASA should have consulted scientific experts before reaching its conclusions, and has made some very fine distinctions about what we can and cannot say, but we will be examining the adjudication carefully to see what communication lessons can be learned in future.”

Egan also stated he was pleased the ASA “validated the majority of the points” Cuadrilla made in its leaflet.