1. What are cookies
A cookie is a small text file that is stored on your device by your browser when you visit a website. Cookies allow the site to recognise your device on subsequent visits, maintain your session, and remember preferences such as language or display settings.
Cookies can be session cookies, which are deleted when you close your browser, or persistent cookies, which remain on your device until they expire or you delete them. They can also be first-party (set by us) or third-party (set by services embedded on the page).
2. Strictly necessary cookies
These cookies are essential for the website to function. They cannot be disabled. They do not track you across other websites and contain no personal information beyond what is needed to maintain your session and preferences.
| Cookie name | Purpose | Duration |
|---|---|---|
| nmchem_gate | Researcher access gate session | 30 days |
| woocommerce_cart_hash | Stores cart state to detect changes | Session |
| woocommerce_items_in_cart | Indicates whether the cart contains items | Session |
| wp_woocommerce_session_[hash] | Links your cart to your browsing session | 2 days |
| wordpress_[hash] | WordPress authentication cookie for logged-in users | Session |
| wordpress_logged_in_[hash] | Indicates logged-in status for WordPress | Session |
| PHPSESSID | Standard PHP session identifier | Session |
| nmchem_consent | Remembers whether you accepted or rejected optional cookies, so we do not ask again | 1 year |
| __cf_bm | Set by Cloudflare, our security provider, to distinguish people from automated traffic | 30 minutes |
3. Functional cookies
Functional cookies remember your preferences and improve your experience. They are not strictly necessary, but their absence may affect features of the site.
| Name | Purpose | Duration |
|---|---|---|
| nmchem-theme | Stores your light or dark mode preference | Persistent (local storage, not a cookie technically) |
Note: this item is stored in browser localStorage rather than as a cookie, but is disclosed here for full transparency.
4. Optional cookies (only with your consent)
None of these are set unless you click Accept on the cookie banner. If you click Reject, they are not set, and any already on your device from an earlier visit are removed. You can change your mind at any time by deleting the nmchem_consent cookie, which brings the banner back.
| Cookie name | Set by | Purpose | Duration |
|---|---|---|---|
| _ga | Google Analytics | Distinguishes visitors so we can count how the site is used | 2 years |
| _ga_[ID] | Google Analytics | Keeps track of your current visit for the same purpose | 2 years |
| sbjs_current, sbjs_current_add, sbjs_first, sbjs_first_add, sbjs_session, sbjs_udata, sbjs_migrations | WooCommerce | Record how you found the site (for example a search engine or a link) so we can see which sources lead to orders | Session (cleared within 30 minutes) |
| mailchimp_user_email, mailchimp_user_previous_email, mailchimp_email_id, mailchimp_campaign_id | Mailchimp | Link a basket to the email address you enter, and record which of our emails you arrived from, so we can send a reminder about an unfinished order | 28 days |
Google Analytics runs in Google Consent Mode: until you accept, it receives no cookies and stores nothing on your device.
5. Managing your cookies
You can manage cookies through your browser settings. Each major browser provides controls to view, block, and delete cookies: in Chrome, via Settings → Privacy and security → Cookies; in Firefox, via Settings → Privacy & Security → Cookies and Site Data; in Safari, via Preferences → Privacy; and in Edge, via Settings → Cookies and site permissions. Detailed step-by-step instructions for all major browsers are available at aboutcookies.org.
Blocking strictly necessary cookies will prevent the site from functioning correctly, including the researcher access gate and the shopping cart. You will not be able to complete a purchase if these cookies are blocked.
Deleting the nmchem-theme localStorage entry will reset your theme preference. You can find localStorage in your browser's developer tools, typically under the Application tab (Chrome and Edge) or the Storage tab (Firefox and Safari), where you can inspect and delete entries by origin.
6. Changes to this policy
We will update this page when our cookie use changes. The date at the top of this page reflects the current version.