Each year consumer products are involved in millions of injuries and thousands of fatalities. Responsibility for this rests with the manufacturers. Most developed countries have also established government agencies that provide regulatory oversight. In the US, the Consumer Product Safety Commission (CPSC) maintains regulatory jurisdiction over more than 15,000 types of consumer products.
Consideration for public safety can improve product development and product quality. Formal tools of quantitative risk assessment add value by improving decision making at different stages.
Product characteristics and analysis of historical data on product-related injuries and deaths can inform safety assessment of a product design before it is manufactured.
Unintended declines in the quality of consumer items can pose safety hazards to consumers, causing unexpected financial burdens and potential legal liabilities to manufacturers. At the beginning of the production process, companies may implement acceptance sampling plans to ensure the quality of raw materials or components. The acceptable quality limits (AQLs) used in such plans can be chosen on the basis of a quantitative risk assessment. Standard tools for statistical process control are routinely deployed by manufacturers to provide checks on quality. A motivating principle is that successful business operations require continuous effort to reduce variation in process outputs. End-of-line testing is typically performed before manufacturers approve products for shipping to customers. In some industries such testing may be required by government regulation.
Information about the performance of a product after release to consumers comes from returns, warrantee programmes, and complaints. Records of incidents involving failure of a product during operation typically include information such as model and serial number of the unit, production date or date code, incident date, and location. In monitoring field performance, a manufacturer needs to determine whether an adverse change has occurred and, if so, assess its implications for product reliability and safety. If a background level of event risk is accepted, statistical methods can determine whether adverse events can be explained by random variation or require attention. Production, shipping, and sales records typically provide the raw data for such analyses.
Confirmation of a problem raises a series of questions: How bad is it? Do field data point to a particular production period or facility? A quantitative risk assessment can address these questions using statistical estimation and hypothesis testing. Risk analysts review the information about production history and seek changes in time period, plant, process, equipment, design, or supplier that are associated with subsequent problems. Parametric statistical models are frequently used to fit time-to-failure distributions in engineering applications.
Product recalls require identification of the units affected, typically by time or source of production, and determination of whether affected units will be repaired or replaced. Increasing globalisation challenges manufacturers and regulators of consumer products, as a product may contain components from different nations and be sold all over the world.
The process for implementing corrective action varies from country to country. In 1997 the US CPSC adopted a “Fast Track Product Recall Programme” for reports filed according to Section 15(b) of the Consumer Product Safety Act (CPSA). This programme requires manufacturers, distributors, and retailers of consumer products to notify the commission of certain defects, unreasonable risks, or noncompliance with voluntary or mandatory stan¬dards. Under the CPSC Fast Track programme, the staff refrains from making a preliminary determination when firms report and implement an acceptable corrective action plan. The plan submitted to CPSC must describe the recall action (refund, repair, or replace) that the company will take to eliminate the identified risk, and provide sufficient information on the product design, incident, and testing to allow the CPSC staff to determine whether the proposed action can correct the identified problem.
An effective risk assessment must link measured levels of risk to specific corrective actions. Supporting tools have been developed, particularly in the EU.
A community rapid information exchange system known as RAPEX assesses the risk of potentially hazardous consumer products by first considering (a) the probability of health damage from regular exposure, and (b) the severity of injury from the product. Depending on the probability and severity of damage the RAPEX method then classifies the overall gravity of an adverse outcome on a five-point ordinal scale ranging from very low to very high. The final judgment of whether the risk requires corrective action considers three additional factors: (a) the vulnerability of people exposed to the product, (b) whether the hazard is obvious to nonvulnerable adults, and (c) whether the product has adequate warnings and safeguards. The RAPEX methodology is sometimes viewed as the preferred approach in countries adopting a risk-averse approach to consumer product safety based on such rough scoring.
Although consumer products are required to be safe, safety does not mean zero risk. A safe product is one that has reasonable risks, given the magnitude of the benefit expected and the alternatives available. In managing consumer product risk, quantitative risk assessment and associated statistical methods are used to frame substantive issues in terms of estimable quantities and testable hypotheses, to extract infor¬mation on product performance from data on field incidents and manufacturing records, and to com¬municate findings to upper management, regulatory authorities, and consumers.
This article is an edited version of an entry in the “Encyclopedia of Quantitative Risk Analysis and Assessment”, Copyright © 2008 John Wiley & Sons Ltd. Used by permission.
