How to prioritise chemicals during acquisition due diligence

The rules that matter depend on where the products are sold and to whom, so define the scope first. List each product with its formulation, the markets it is sold in, whether it goes to consumers or professional users, and any claims it makes, such as disinfecting. Add the markets the buyer plans to enter, because they bring their own rules.

Take a fictional target, Ostlake Hygiene, which makes household and institutional cleaning products. It sells in the EU and the US, including California and Minnesota. Its range includes all-purpose cleaners, a solvent degreaser for workshops, floor polishes, laundry products with encapsulated fragrance, and a surface disinfectant. The buyer plans to sell the household range in more EU countries.

Ask for full formulations, not safety data sheets alone. A safety data sheet lists only the ingredients its hazard classification requires, so it can miss restricted substances at low concentrations, fragrance components and impurities. For each ingredient, get the CAS and EC numbers, the concentration, its function and its supplier. For fragrances, get the fragrance supplier's breakdown of allergens and restricted substances.

Then collect the records that show how the target has met its duties. In the EU these include biocidal product authorisations, and evidence that each active substance supplier is on the list in Article 95 of the Biocidal Products Regulation. In the US they include pesticide registrations for products with antimicrobial claims, ingredient disclosures under California's Cleaning Product Right to Know Act, and PFAS reports filed in Minnesota. Ask for past reformulation decisions and correspondence with regulators, which show what the team already knew.

Screen each ingredient against the official records, and read each entry in full. A CAS number search can miss group entries and the conditions that limit a rule to certain uses or concentrations.

In the EU, the main records are harmonised classifications in Annex VI to the CLP Regulation and its amendments, the REACH Authorisation List in Annex XIV, the restrictions in Annex XVII, and the Candidate List of substances of very high concern. Then check the European Chemicals Agency's registries of intentions for harmonised classification, substances of very high concern and restrictions. For cleaning products, add the Detergents Regulation and the Biocidal Products Regulation.

In the US, check the rules under section 6 of the Toxic Substances Control Act in 40 CFR Part 751, state laws such as Minnesota's and Maine's bans on PFAS in cleaning products, and California's disclosure rules. Check court records too. On 15 September 2026, the Fifth Circuit vacated the EPA's 2024 rule restricting methylene chloride, but the eCFR, current to 9 October 2026, still showed it. A screen of the Code alone would have missed that.

Date each check. The record changes often. For example, the Candidate List had 253 entries on 14 October 2026, and its last update was on 4 February 2026.

Ostlake's issue register sorts each finding by status.

Applies now. The workshop degreaser contains trichloroethylene. The EPA's rule prohibits processing and distributing it, including by retailers, after 16 June 2025, and most industrial and commercial use after 15 September 2025, with some uses exempt until later (40 CFR 751.305). A floor polish for consumers contains a fluorosurfactant. Since 10 October 2026, REACH has restricted PFHxA, its salts and related substances in mixtures for the general public (Annex XVII, entry 79), with an exemption for goods already on the market before that date. Minnesota has banned cleaning products with intentionally added PFAS since 1 January 2025, and Maine since 1 January 2026.

Adopted with a future date. A degreaser variant contains perchloroethylene. The EPA's rule prohibits distributing it to retailers after 8 December 2026, and its industrial and commercial use after 7 June 2027 (40 CFR 751.605). The laundry range's encapsulated fragrance falls under the EU microplastics restriction from 17 October 2029 (Annex XVII, entry 78). The new EU Detergents Regulation (EU) 2026/405 applies from 23 September 2029, with new labelling rules including a longer list of fragrance allergens. A preservative, IPBC, gets a stricter harmonised classification from 1 February 2027, which may change labels.

Proposals. The EU's universal PFAS restriction had a final opinion from ECHA's risk assessment committee on 2 March 2026, and its socio-economic committee expects to adopt its final opinion by the end of 2026. The Commission then proposes a restriction for Member States to vote on. A draft amendment to CLP Annex VI, notified to the WTO in November 2025, would classify tea tree oil as toxic for reproduction, category 1B. Ostlake's natural range uses it.

Each finding becomes a question for the seller and, where needed, a remediation task with an owner and date. For the trichloroethylene degreaser, ask when sales stopped, what stock remains, and which customers received it after the prohibition dates. For the fluorosurfactant polish, ask for test results for PFHxA and related substances, and the date each batch was placed on the market. Ask for Minnesota sales records and any PFAS reports or extensions.

Adopted future rules become cost estimates. Price the reformulation of the perchloroethylene variant before its 2027 dates, the replacement of encapsulated fragrance before October 2029, and new labels for the Detergents Regulation and the IPBC classification. Proposals become watch items with a trigger, weighted by how far each has progressed. If the tea tree oil classification is adopted, the natural range needs relabelling or reformulation.

Give the register to the team that will own the products after closing, so the open items carry on as monitored tasks.